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CLIMSEAS Project

Seminars

Contact

 

Scientific coordinator

Elena Roget correu

Web contents manager

Anna Drou correu

Seminars

 

In this section, presentation and working seminars organized to articulate the project are presented. Please refer to them using the CLIMSEAS reference identification indicated below the summary of each one (i.e.  Ivanova, E. 2010. Rapid climate and environmental changes in the Barents Sea during the postglacial epoch.  CLIMSEAS2010_S1 in Seminars at www.udg.edu/climseas/). Some of the results included in the seminar presentations have already been published in papers or presented in conferences and can be found in the Outputs section. Attached images illustrate the exchange progress at the host institutions (to enlarge the images right click on the photo).

 

 

Rapid climate and environmental changes in the Barents Sea during the postglacial epoch
Elena Ivanova, Shirshov Institute of Oceanology RAS

 

Elena Ivanova

The first part of the talk represented an overview of the existing knowledge on the orbital and millennial-scale climate variability, abrupt changes, controlling factors and feedbacks. The second part summarized the author’s recent study of the Barents Sea’s paleoceanography and paleoenvironments. The surface and sub-surface Atlantic water inflow into the Barents Sea strongly affects the regional climate and, in turn, is modulated by the outflow of Arctic water. The complexity of the postglacial climate in the Barents Sea is proven by the fact that different sites do not respond equally and synchronously to the rapid climate changes. In particular, this was demonstrated by our multi-proxy data on oxygen and carbon isotopes, paleotemperature, planktonic and benthic foraminiferal assemblages, and grain size distribution of sediments from specific oceanographic settings. These proxy records point to pronounced and sometimes abrupt climatic and paleoceanographic changes in the main Atlantic water passage in the southwestern Barents Sea during the Bølling/Allerød warming, the Younger Dryas cooling, the early and late Holocene, and on the sub-surface Atlantic water passage in the Franz Victoria Trough during and after the Holocene thermal maximum.

Modelling experiments have been performed to investigate a possible influence of variations in the Atlantic water input and NAO on the Holocene environmental changes inferred from the paleo-data. All together paleo-data and modelling results point to the primary importance of these two factors for regional climate and environmental changes. Further study is necessary to assess the effects associated with the variability in sub-surface Atlantic water inflow into the Barents Sea via the northern troughs. The third part of the talk provided basic information about the recent warming and its environmental and social consequences, notably for the Arctic.

 

Presentation. (Ref: CLIMSEAS2010_S1)

UBRUN, London. June 2010.


Environmental Fluid Dynamics Group: from ASU to ND
Iossif Lozovatsky, University of Notre Dame

 

seminari Iossif 2010

During the CLIMSEAS evaluation process the Center for Environmental Fluid Dynamics at Arizona State University moved to the University of Notre Dame in Indiana. The University of Notre Dame and the Environmental Fluid Dynamics Group, now home to the laboratory from Arizona, are presented in the first part of the talk. The second part reviews ongoing projects of the researchers that have moved from Arizona to Indiana. They include the study of mesoscale dynamics and lateral mixing in the China Seas and the Western Pacific, laboratory experiments and parameterization of the ripple dynamics and benthic transformations under variable wave forcing, wakes of maneuvering bodies in stratified fluids, double diffusive convection in SPR caverns, and the modeling of atmospheric flows and urban pollutants. The third part is devoted to the presentation of the Center for Aquatic Conservation at the University of Notre Dame.

 

 

Presentation. (Ref: CLIMSEAS2010_S2)

UdG, Girona. June 2010.


Bottom mixing dynamics within a turbid bottom layer
Imma Bastida, University of Girona

 

Imma2

Based on microstructure data the dynamics of a turbid bottom layer at the slope of a shallow zone in the Catalan coast of the Mediterranean Sea was analysed during a stratified period. Turbidity, precision CTD, and temperature and shear microstructure measurements were taken from a free falling profiler along a 25 km cross-shore transect in the north-western Mediterranean area during the 2004 campaign within the Response Project CMIMA (EU). The area was affected by a regional coastal current. Quasi inertial frequency oscillations in the area as well as mean velocity magnitude and direction were determined from recorded current meter measurements. Baroclinic modes were found and related to meteorology, specifically after two consecutive wind bursts. A second baroclinic mode is deduced to be excited in one case. Observational data also demonstrated the correspondence between the turbidity layer and local physical mixing processes, including the near-critical (sub-critical) reflection of internal waves, which our data support. Current and remaining mixing events recorded during the campaign are documented to show a rather high mixing activity below the thermocline, which is linked to the internal-inertial waves and baroclinic modes.

 

Presentation. (Ref: CLIMSEAS2010_S3)

SIO, Moscow. June 2010.


Seasonality and interdecadal changes in variability of European climate
Igor Zveryaev, Shirshov Institute of Oceanology RAS

 

IGOR_ZVERYAEV

The author presented results of the analysis of gridded monthly terrestrial precipitation and air temperature for 1901-2000 from the Climatic Research Unit, University of East Anglia (CRU) dataset, which were used to investigate leading seasonal modes in the long-term precipitation and air temperature variability over Europe and their links to atmospheric circulation. While long-term linear trends of precipitation and air temperature are mostly positive for all seasons and differ only in terms of strength and significance, leading modes of precipitation and air temperature variability over Europe are clearly season-dependent.

The first empirical orthogonal function (EOF) modes of winter, spring, and summer seasonal mean precipitation over Europe are associated with the North Atlantic Oscillation (NAO). However, because the summer NAO differs significantly from the winter and spring NAO, the first EOF mode of the summer precipitation has a spatial-temporal structure that is principally different from those of the winter and spring seasons. The first EOF mode of the fall precipitation is not associated with the NAO. This mode demonstrates a strong link with the Scandinavian teleconnection pattern. The second EOF modes of the winter and fall precipitation are linked respectively to the East Atlantic and the NAO teleconnection patterns.

 An analysis of running correlations between the principal components of the leading EOF modes of precipitation and air temperature and the NAO index has revealed essential non-stationarity of the links between European precipitation and the NAO. Moreover, there is evident seasonality in the character of long-term changes of the above links. Singular value decomposition analysis has shown that during certain climatic periods characterized by the weak influence of the NAO on the European climate, other regional teleconnections (such as Scandinavian and East Atlantic – West Russia teleconnections) play a role of major drivers for European climate variability.

 

Presentation. (Ref: CLIMSEAS2010_S4)

UBRUN, London. June 2010.


Factors affecting UV radiation
Jordi Badosa, University of Girona

 

Badosa2

The sun emits electromagnetic radiation mainly from 200 to 4000 nm. The solar ultraviolet radiation (UVR) (200-400 nm) reaching the top of the atmosphere is about 8% of the total solar radiation (39% is in the visible band and 53% belongs to the infrared band). UVR reaching the Earth’s surface is even less, both in absolute and in relative terms, as it is strongly absorbed by atmospheric constituents, in particular ozone and clouds. Despite being a small portion of solar radiation, UVR has a decisive role in the atmospheric chemistry and it is necessary for life, though in large amounts it can have serious harmful effects on living organisms. In particular, human exposure to UVR may have serious acute or chronic effects on skin, eyes and the immune system.

UVR is usually decomposed into three ranges, depending on its biological effect: UVC (200-280 nm), UVB (280-315 nm) and UVA (315-400 nm). All of the UVC and most of the UVB are absorbed in the upper atmosphere mainly by the molecules of ozone (O3) (in the bands of Hartley and Huggins) and oxygen (O2) (Herzberg band). UVA is much less affected by ozone.

A widely used variable to study the UVR is the UV Index (UVI), which is a quantitative approach to account for the UV levels that are important for the effects on the human skin. The amount of UVI that reaches a horizontal surface of the Earth is mainly affected by the Sun-Earth geometry, clouds, stratospheric ozone, aerosols, the surface albedo and the topography of the surrounding area. UVI can be measured with broadband radiometers (Robertson-Berger type) and spectroradiometers. Both instruments have been used and are presented in this presentation. UVI can also be modelled using simple parameterizations or radiative transfer models. TUV radiative transfer model is used to model UVI in the presented studies as well as PTUV, which is a parameterization of TUV for faster calculations. UVI model vs measurement analyses are very useful as quality control of the measurements and also to investigate the effect of the factors on UVI. Some particular results are shown to highlight the effects of aerosols and ozone on UVI.

Finally, to show the most recent investigations that we are undertaking, the effect of clouds on UVI is finally investigated. This effect is highly spatially and temporally variable so it is the factor that affects UVI with the largest uncertainty. For this, cloud cover information comes from total sky images (TSI) using a red-blue algorithm. Preliminary results of the effect of clouds on UVI for different solar zenith angles and cloud types are shown. The cloud enhancement effect is also investigated.  

 

Presentation. (Ref: CLIMSEAS2010_S5)

RHMC, Moscow. July 2010.


Hydrometeorological Research Centre
Valentina Khan, Hydrometeorological Research Centre of the Russian Federation

 

Valentina2

The objective of the presentation was to give the audience a general overview of the Hydrometcentre of Russia (RHMC) since this institution is a participant in the CLIMSEAS project. The Hydrometcentre of Russia, established on the basis of the World Meteorological Centre and Central Forecasting Institute, was founded on January 1st, 1930. In 1996 it was given the status of the State Scientific Centre of the Russian Federation by government decree. Its principal tasks are investigation of the atmosphere-ocean-land system for the purposes of hydrometeorological forecasting and providing the general population, policy makers and economists with operational hydrometeorological information, including warnings on adverse and disastrous weather phenomena. The principal areas of research are: 1) weather forming processes; 2) modelling and monitoring of atmospheric circulation; 3) modelling of the oceanic processes, investigation of the atmosphere-ocean interaction and hydrological processes on continents; 4) development of hydrometeorological forecasting methods; and 5) development and putting into operation new information technologies. There are 18 departments and laboratories and 11 other administrative and management units. The RHMC is in charge of preparing the general purpose hydrometeorological information and of providing specialized hydrometeorological services.

Custom hydrometeorological research and engineering work is also a part of RHMC activities. The users of the RHMC include executive authorities, the mass media, aviation, fleet and land transport specialists, the energy sector, agriculture, the armed forces, construction firms and other public and commercial organizations. Staff members of three laboratories, namely the Physics of the Atmosphere Numerical Research Laboratory, the Large-Scale Atmospheric Circulation Modelling Laboratory and the Long-Range Forecasting Laboratory are members of the CLIMSEAS project. The participation and working tasks of RHMC members within the project are briefly discussed.   

 

Presentation. (Ref: CLIMSEAS2010_S6)

UdG, Girona. July 2010.


Two studies on the Northern Hemisphere Annual Mode
Vladimir Kryjov, Hydrometeorological Research Centre of the Russian Federation

 

VKryjov

The Northern Hemisphere annular mode (NAM) is a dominant mode of atmospheric variability of the northern hemisphere. It strongly affects the weather and climatic conditions in the region of inland seas studied in our project. At the seminar, two NAM-related issues were discussed: the influence of the wintertime NAM on the following autumn circulation and temperature in Eastern Europe, and possible causes of the extremely low NAM index of last winter (2010).

In the first study, presented at the seminar, it was shown that winters with positive NAM index polarity tend to be followed by autumns with enhanced northern advection and negative temperature anomalies over East Europe and vice-versa. The mechanism of such delayed atmospheric response to the wintertime NAM is likely to be Arctic Sea ice, whose summer extent depends on wintertime circulation that, in turn, affects autumn circulation. In the second study, it was shown that the extremely cold 2009-10 winter in North Eurasia was associated with extremely negative NAM index polarity, i.e. extremely weak zonal and enhanced meridional circulation. The El Niño last winter was very strong.

Previous studies have shown that the ENSO may influence the NAM in both stratosphere and troposphere by planetary waves due to enhanced planetary Rossby wave activity during El Niño winters. The waves propagate into the stratosphere and interact with the polar vortex. Excited variations in the polar vortex intensity, indicated by the NAM index polarity and magnitude, communicate downward to the troposphere. However, the relationships between the NAM and ENSO appear statistically insignificant. So are direct correlations between the NAM and ENSO indices. Kryjov and Park (2007) have suggested that the alteration of planetary wave propagation in the stratosphere associated with different phases of solar activity in its 11-year cycle is the cause of the low statistical significance of the relationships between the ENSO and NAM when the solar effect is not accounted for, i.e., there is solar modulation of the ENSO impact on the NAM. Their study reveals that the ENSO strongly impacts the NAM only during solar cycle minima, with the autumn-winter El Niño exciting the negative winter NAM polarity and considerably weakening the zonal flow. The winter of 2009-10 was a solar cycle minimum winter and an autumn-winter El Niño with enhanced planetary Rossby wave activity in the autumn. The combined action of these phenomena has resulted in considerable weakening of the zonal circulation, enhancement of the meridional circulation, and corresponding weather conditions that are reflected in the extremely low NAM index.

 

Presentation. (Ref: CLIMSEAS2010_S7)

UdG, Girona. September 2010.


Impact of the large-scale atmospheric forcing on the long-term variability of surface temperature in the Black Sea
Alexander Kazmin, P.P. Shirshov Institute of Oceanology RAS
 

kazmin

Satellite, in situ and reanalysis data for the period of 1950-2005 were used to study the long-term variability of sea surface temperature (SST) in the Black Sea and its connection with the major large-scale atmospheric forcing (air temperature, surface wind and North Atlantic Oscillation - NAO). In contrast to the quasi-regular decadal oscillations of the SST typical for the Northern Atlantic, the pattern of long-term SST variability in the Black Sea is better described as intermittent periods of SST increase/decrease with durations of approximately 6-10 years and short (1-2 years) and quite abrupt transitions between them. The known existence of two major surface wind regimes over the Black Sea, i.e. Southern-Western (SW) and Northern-Eastern (NE), and new details on the correlations between the zonal and meridional wind components in each regime are added. A new important finding is that the switch between two regimes occurs quite abruptly at values of the NAO index slightly less then zero. It was shown that in high NAO situations the SW wind regime prevails and wind components are well correlated with the NAO index. The long-term variability of winter-mean SST in the Black Sea is reasonably well correlated with the variability of surface air temperature (SAT), which in turn is highly correlated with the meridional component of surface wind. It is shown that the strengthening/weakening of the southern wind or the weakening/strengthening of the northern wind cause an SAT and SST increase/decrease. Finally, a conceptual diagram of the NAO impact on the meridional component of the surface wind, SAT and SST is presented.

 

Presentation. (Ref: CLIMSEAS2010_S8)

UdG, Girona. September 2010.


Palaeoenvironmental and palaeoclimatic changes in the Caspian Sea region since the Lateglacial from palynological analyses of marine sediment cores
Suzanne Leroy, Brunel University

 

Suzanne2

The Caspian Sea has known many small and large scale changes of its water level which have in recent times had a dramatic impact on socio-economic activities around it (Kazancı et al., 2004; Leroy et al., 2010). To reconstruct past sea level changes in the Caspian Sea (CS) and the past climate of the region, the traditional approach has been to look at outcrops, to analyse their sediment and micro/macrofossil contents and to obtain radiocarbon dates on bivalve shells. Low stands are not recorded with this method other than by a hiatus. The CS level variability is dominated by the variability of precipitation over the Volga River basin. The precipitation during summer plays a dominant role and can explain two major events that happened in the 1930s (drop) and after 1977 (rise) (Arpe and Leroy, 2007). At a longer timescale it is not impossible that other drivers of water level change, such as anthropogenic and tectonic ones, played a role. Recently marine cores have been obtained in the shallow and, more rarely, in the deeper central and southern basins of the Caspian Sea. Multidisciplinary analyses covering both low and high stands hold the key to understanding when sea level changes occurred, which is an important step before understanding why they occur.

 

Presentation. (Ref: CLIMSEAS2010_S9)

SIO, Moscow. September 2010.


Shirshov Institute of Oceanology - RAS
Peter Zavialov, P.P. Shirshov Institute of Oceanology RAS

 

zavialov

In the first part of the presentation, a general overview of the Shirshov Institute of Oceanology of the Russian Academy of Sciences (IO RAS) was given. IO RAS is one of the world’s largest oceanographic institutes, numbering about 1600 employees, and operating a fleet of six oceanic research vessels. The Institute has regional branches in the Black, Caspian, White, and Baltic seas. The main objectives of the Institute lie in an interdisciplinary study of the world’s oceans and the Russian seas based on the entirety of the physical, chemical, biological and geological processes observed in them, laying scientific foundations for forecasting the Earth’s climate variability, rational using marine resources and safeguarding ecological security in the interests of sustainable development. The Physical Oceanography Division (POD) of SIORAS employs 161 scientists and engineers, as well as about 20 graduate students. The POD encompasses 13 departments, dedicated to particular areas of physical oceanography, ranging from turbulence and microscale processes to global ocean circulation and climate change. In the second part of the presentation, we reported some specific and recent results focused on dynamics in enclosed seas. In particular, we described a field investigation of a river plume in the Black Sea, indicating that the downwelling conditions favour the maximum spatial development of the plume. The dynamics of continental discharges is one of the important controllers of climatic variability in the inland seas. We also described findings from recent field investigations in the Aral Sea, in particular, those related to the abrupt ongoing changes of its thermohaline regime. Other relevant issues were also discussed.

 

Presentation. (Ref: CLIMSEAS2010_S10)

UdG, Girona. August 2010.


The modern state of the cloud cover and cloud microphysical property simulations in weather forecast and climate models
Lydia Dmitreva, Hydrometeorological Research Centre of the Russian Federation.
Marina Shatunova, Hydrometeorological Research Centre of the Russian Federation.

 

LidiaMarina3

The first part of the seminar was dedicated to cloud cover simulations in weather forecast and climate models. The comparison of methods for cloud cover parameterization used in the different hydrodynamic atmospheric models was presented. The vertical distributions of the critical relative humidity value and cloud cover were shown. It was noted that the cloud cover parameterization methods are the tuning parameters of the models. In the second part the principal theses of the method for the parameterization of the microphysical properties of stratiform clouds were presented. Cloud microphysical properties obtained from full-scale experiments were shown. The simulation results of the droplet size distribution function in the dependence of the form factor and mean droplet radius were displayed. Simulation results of the humidity transformation model (Dmitrieva-Arrago, 2004) for the space distribution of the cloud cover, integral cloud water content and mean droplet radius were also displayed. A basic description of the calculation method for the heat and radiation budget of the surface that is used in the COSMO-RU model was presented in the third part. Calculated values of the heat budget components were shown. A comparison of these values allows an evaluation of the required calculation accuracy of the corresponding fluxes. The experimental results of the sensitivity of the surface temperature to the variation of the absorbed solar radiation and cloud water content (CWC) were displayed.

 

Presentation. (Ref: CLIMSEAS2010_S11)

UdG, Girona. October 2010.


Black Sea dynamics: general aspects and recent results
Slava Kremenetskiy, P.P. Shirshov Institute of Oceanology RAS

 

kremenetskiy2

Spatial and temporal variability of hydrophysical structure and water dynamics on scales of 100-102 km and 100-102 hours is closely related to shelf-deep sea water exchange processes that are responsible for the shelf’s water renewal and self-purification from natural and anthropogenic pollution. These variability and water-exchange processes depend on a number of factors: wind regime, coastal relief and bottom topography, fresh water runoff, circulation regime over the continental slope and the deep part of the sea. The contribution of single mentioned factors is unknown, as it is for a combination of factors, and further investigation is required. In the talk a major feature of Black Sea circulation system is presented in relation to wind forcing, coastal relief and bottom topography. Different spatial scales of dynamic processes, from basin-scale to sub-mesoscale, are described and discussed. A new autonomous profiling system Aqualog, developed in IO RAS, is presented, as well as recent results obtained by means of Aqualog.

 

 

 

 

Presentation. (Ref: CLIMSEAS2010_S12)

UdG, Girona. November 2010.


Horizontal convective exchange flows above sloping topography
Irina Chubarenko, P.P. Shirshov Institute of Oceanology RAS

 

Irina2

Exchange flows, resulting from the temperature difference between shallow and deep waters, have many common features with what is known as horizontal convection. In this presentation, the descent of denser water and ascent of lighter water along slopes, resulting from differential coastal heating/cooling, are considered as environmental manifestations of horizontal convection. This allows descriptions of many specific features of thermally-induced cascading and upwelling processes in lakes, seas and oceans, as well as processes of the thermal bar and day/night circulation. The mechanism behind the formation of horizontal temperature/density gradients above underwater coastal slopes of natural basins was considered. It was shown that the formation time of the gradients is rather small (tens of minutes for a thermocline depth of tens of meters), but the corresponding flows may not develop even in a day-long cycle. The time dependence of the horizontal water exchange between the shallow and deep areas is analytically treated. The spatial scale of the problem is the main parameter that defines the resulting quasi-stationary value of the water exchange. Joint analysis of the published field, laboratory, and numerical data of many authors in the range of the above slope depths of 10**(–2) m < d < 3 × 10**2 m (d ≤ D, where D is the thickness of the upper thermally active layer of a basin) indicates that the relation between the value of the horizontal quasi-stationary volumetric water exchange and the local depth looks like Q = 0.00l3 × d**1.37 (R**2 = 0.96). Horizontal convective water exchange is shown to be generally two-layered, ageostrophic, and exhibits its maximum flow rate at the end of the slope. Conclusions are drawn for lakes and inland seas, where differential coastal heating is manifested at scales comparable to the scale of the basin itself. 

 

Presentation. (Ref: CLIMSEAS2011_S1)

UdG, Girona. January 2011.


Baltic Sea lagoons: observations of physical processes and climate change manifestations
Boris Chubarenko, P.P. Shirshov Institute of Oceanology RAS
 

bORIS2

We focus our interest on five coastal lagoons in the Baltic Sea, namely the Darss-Zingst Bodden Chain (Germany), the Sczcecin Lagoon or Oder Estuary, the Vistula Lagoon and the Curonian Lagoon, and Neva Bay. The last one is a recently made, artificial, lagoon-type water body bordered by artificial dams. All of them could be considered as choked estuarine type lagoons. Definitions and typologies of lagoons were discussed. The estuarine lagoons are arenas of permanent mixing of sea- and river-originated waters. Two types of water (sea and river) experienced permanent transformation within the lagoon. But it is an experimental fact that water characteristics in a lagoon do vary not continuously (linear change between marine and fresh waters), but stepwise. And those compartments in a lagoon with individual characteristics bordered by local frontal zone. The examples for the Darss-Zingst Bodden Chain and Vistula Lagoon were presented. External factors influencing mixing in the lagoon were discussed. In hydraulics two aspects of the mixing process leading to waters originating with intermediate characteristics are considered: (i) the mechanical exchange (steering) of a considerable amount of water with given characteristics by another one due to external forcing leading to the formation of intermediate, spatially averaged characteristics, and (ii) proper mixing as a final act of steering, when a water volume with individual characteristics becomes less than what the sensor measured (e.g. CTD sensor). Field measurements showed that the intrusion head accompanies eddies. Frontal divisions in different hydro-physical parameters do not coincide with each other. It indicates different rates of diffusion in a moving frontal zone around the intrusion head. As one mechanism of mixing, the Langmuir circulation was discussed in special commemoration of Prof. Irving Langmuir and on the occasion of his 130th birthday (31 January 1881). Examples of hydrophysical measurements across the circulation pattern in the Darss-Zingst Bodden Chain and the Vistula Lagoon were demonstrated. The conclusions were: Rolls structure is developed after 5-10 minutes of wind starts blowing. The vertical scale of Langmuir circulation in shallow waters is limited by depth. The processes of junction and disintegration of roles are in equilibrium, and Y-junctions of all four types are present. In addition, information was given about the study of the resuspension process in the Vistula Lagoon comprised from field measurements and analytical estimations on the basis of the wind assumption. In conclusion, the rise in level observed in the Baltic lagoons, attributed to recent climate change, was illustrated by data and discussed. 

 

Presentation. (Ref: CLIMSEAS2011_S2)

UdG, Girona. January 2011.


The classification of troposphere circulation patterns corresponding to blocking anticyclone situations in the Atlantic-European sector
Vladimir Tischenko, Hydrometeorological Research Centre of the Russian Federation

 

tischenko2

A catalogue of stationary anticyclones in the Euro-Atlantic region for the period from 1949 through 2007 developed at the Russian Institute of Hydrometeorological Information (RIHMI-WDC) and the Hydrometeorological Centre of Russia was analysed. This catalogue was created from the analysis of daily synoptic charts and contains information about the time of persistence of stationary anticyclones, their localization, the maximum pressure value in their centre at the surface and at the 500 hPa level. The classification of blocking anticyclones in the Atlantic-European sector and analysis of large-scale circulation in the lower and middle troposphere prior to and after the formation of blocking anticyclones for the types were carried out. Euclidian distance and correlation coefficients were used as similarity criteria for fields of H500, H1000 and T850 in the objective classification. As a result, it was found that the optimal number of blocking anticyclone types is 10. A regionalization of anomalies of the temperature and pressure regime in the European part of Russia for each type of blocking anticyclone has also been performed. It was found that there is a good agreement between the fields of T850 anomalies and flows in the middle troposphere. In the areas of potential block in the lower troposphere, the prior formation of hot and cold dipoles were revealed. Reformation of T850 fields after decay of the block occurs slowly during a period of up to six days. Preliminary analysis showed that the classified types of H500, H1000, and T850 fields preceding the blockings contain prognostic information about subsequent changes in the thermobaric regime during the blocking and within a few days of the destruction of the anticyclone.

 

Presentation.  (Ref: CLIMSEAS2011_S3)

UdG, Girona. February 2011.


CLIMSEAS project, progress and possible collaborative work with the UdG.
Ongoing activities of the CLIMSEAS project.
Elena Roget, University of Girona

 

elena2

The CLIMSEAS program, including the partners and the scientific objectives, is presented briefly. The program was officially presented at the UdG, the coordinating institution, with the participation of the coordinators of the program at RHMC and SIO, the vice-rectors of research and of international relations of the UdG and the Russian consul in Barcelona. The University of Girona – now with more than 14,000 students – was founded in1991. It is headquartered in the building where the widely recognized medieval university of Girona was located until 1717, when the rights of Catalonia were suppressed and the university was closed. In the presentation, the stays that have already occurred within the program are reviewed.

The research lines of the Environmental Physics group at UdG, to which most of the UdG participants belong, are also presented briefly. Double diffusion convection studies in  a lake are mentioned and it is emphasized that the ratio between the length scale of instabilities within the convective layers was found to be about 1/3 of the height of the stair case vertical structure observed on the scalar fields. The fittings of different flux models to the experimental data of the studied case, with a small stability ratio of 1.1, are discussed. Other convective examples at the upper surface layer of the ocean or of a reservoir are also discussed based on microstructure data. Turbulent patch detection techniques are mentioned and an example based on data recorded on the shelf of the Mediterranean Sea is presented to illustrate the link between mesoscale and small-scale dynamics.

Scientific collaboration results obtained within the first six month of the program are also reviewed. In the presentation 2 it is also mentioned a) the analysis of the cloud  data recorded at more than 1051 meteorological stations at the region studied by CLIMSEAS, b) the wind field data from reanalysis that have been downloaded from CFSR from 1970 to 2010 for the same region and c) the sensitivity of the net surface fluxes to the cloud cover due to the variation of the sea surface temperature. Without considering short wave radiation, variations of about 15 W/m2 were reported for a variation of 1/10 of the cloud cover. The results from the RHMC include the development of the Hydrodynamic Aral Sea data base, the download of SST and heat balance components of satellite data for the Black Sea, and the recompilation of drifter and altimetry data for the same period.

 

Presentation1, Presentation2. (Ref: CLIMSEAS2011_S4)

RHMC and SIO, Moscow. March 2011.


Air-sea interaction and turbulence in the upper boundary layer
Iossif Lozovatsky, University of Notre Dame

 

Iossif

 

After reviewing the main processes of turbulence generation in the surface boundary layer, several challenging problems are raised: diffusivities and mixing efficiency, parameterization of the dissipation via the surfaces fluxes, modeling and intermittency of turbulence, and the effect of the wind bursts. State of the art solutions to these problems are discussed based on the review of standard approaches and the presentation of new results.

 

 

 

 

Presentation. (Ref: CLIMSEAS2011_S5)

 UdG, Girona. May 2011.


Conflicting views on climate and sea level changes in the southern basin of the Caspian Sea
Suzanne Leroy, Brunel University

 

leroy2

Nowadays the Caspian Sea (CS) receives most of its water from the Volga River drainage basin. However, during the Late Pleistocene and the Early Holocene, the Amu-Darya River, via the Uzboy River, flew into the south basin of the CS. The sill that separates the middle basin from the south basin shows signs of overspill. Past salinities, hence past sea levels, are reconstructed from dinocyst assemblages while past climate is reconstructed using pollen and spores and other proxies. A series of cores taken in the south basin covers from the Late Glacial to the present.

Various topics and unanswered questions will be presented such as the Last Glacial Maximum (high or low water level), the Pleistocene-Holocene transition (coincident or not with the end of the Khvalynian transgression and the end of the Eurasian ice sheet), the 4 cal. BP transition (a late drop in sea level, role of western Himalayas and monsoon, and delayed expansion of temperate trees) and the Little Ice Age (high sea level stand). This will be discussed in relation to results from the middle basin, the regional climate and the sources of water for the Caspian basin.

 

Presentation. (Ref: CLIMSEAS2011_S6)

SIO, Moscow. May 2011.


New potentials: Dendrohydrology and Dendroecology
Andy Moir, Brunel University

 

Between the 14th and 15th September four samples from Saxual trees were collected to test their dendrochronological potential during an expedition organized by the SIO. Low ring counts <85 and a failure of cross-matching both within and between the four samples analysed suggest that Saxaul is as a tree species with no dendrochronological potential where it is found on the coast of the Aral Sea. A complete report is appended. 

 

 

 

Presentation. (Ref: CLIMSEAS2011_S7)

SIO, Moscow. May 2011.


Impact of the 2010 drought in European Russia on the Caspian Sea level
Klaus Arpe, Brunel University
 

Klaus Arpe2

The hydrological budgets of the Volga basin (VB) and the Caspian Sea (CS) have been established. The components of the water balance for the CS were calculated for the period 1993 to 2010 with emphasis on summer 2010 when a severe drought developed over European Russia.

A drop in precipitation over the VB in July 2010 occurred simultaneously with a decrease in evaporation for the same area, an increase in evaporation over the CS itself and a drop in the Caspian Sea level (CSL). The drop in the precipitation over the VB cannot have led to an instantaneous drop in the CSL because the precipitated water needs some months to reach the CS. The delay is estimated to be 1 to 3 months for excessive precipitation in summer, longer for other occasions. However, the evaporation over the CS itself is considered to be responsible for a simultaneous drop in the CSL from July to September 2010. The impact on the CSL from the precipitation deficit over the VB occurs in the months following the drought. The water deficit for June to September 2010 calculated from the anomalous precipitation minus evaporation over the VB would decrease the CSL by 22 cm, of which only 2.5 cm had been observed until end of September (Volga River discharge anomaly), 7 cm from October to the end of 2010 and another 5 cm to the end of May 2011. From October 2010 to February 2011 there was excessive precipitation over the Volga basin equivalent to an increase of the CSL of 7 cm which might just compensate the remaining deficit of 7 cm from the summer drought. In previous studies the precipitation over the VB has been identified as the main cause of CSL changes, but of a 10 cm drop from the beginning of July to the end of September, 6 cm can be directly assigned to the enhanced evaporation over the CS itself and 2 cm due to reduced precipitation over the CS.

Further periods with strong changes in the CSL are also investigated, providing some estimates concerning the accuracy of the analysis data.

The investigation was possible due to the new ECMWF interim reanalysis data used to provide data also for sensitive quantities like surface evaporation and precipitation. The comparison with independent data and the consistency between such data for calculating the water budget over the Caspian Sea provides a high degree of confidence in the quality of the data used. This investigation provides some scope for making forecasts of the CSL a few months ahead to allow for mitigating societal impacts.

 

Presentation. (Ref: CLIMSEAS2011_S8)

SIO, Moscow. May 2011.


High resolution remote sensing of inland and marginal seas by ship-borne ultraviolet fluorescence lidars
Vadim Pelevin, P.P. Shirshov Institute of Oceanology RAS

 

Pelevin

In the context of CLIMSEAS project we are studying several regions, and the Black Sea basin is one of the most interesting and important for us. With the help of the ultraviolet fluorescent LIDAR UFL-9, which is developed by our scientific and engineering group at SIO RAS, we try to estimate the small-scale (~10–1000 m) variability of chlorophyll, organic matter and total suspended matter in the estuarine zone of the Mzymta River near the city of Sochi, as well as the modulation of the variability pattern associated with climate change and anthropogenic impacts. To this end, we gather measurement data at 2 Hz LIDAR sampling rate on board the moving vessel. We specifically focus on the relationship between these parameters and oceanographic processes in the region, meteorological conditions and human-induced stresses.

 

 

 

Presentation. (Ref: CLIMSEAS2011_S9)

UdG, Girona. June 2011.


Small-scale variability of chlorophyll, dissolved organic matter and suspended sediment in Lake Balaton, measured by lidar UFL-8 in September 2008
Igor Goncharenko, P.P. Shirshov Institute of Oceanology RAS

 

IgorGoncharenko

Lake Balaton, located about 100 km from Budapest, is Europe's largest lake. It stretches from west to east, and the Zala River flows into western part of the lake. The water of the river is rich in organic and biological substances. The concentration of these substances decreases from west to east. Because of its shallow depth, there is suspended particulate matter, and the water has a silver-green colour due to high concentrations of minerals. The lake level is regulated by engineered devices. The Zala River is located near the south coast.

For the first time a LIDAR system was used in the freshwater of this lake. After the first day of instrumental research on the lake, the LIDAR holding device was corrupted due to vibration onto the boat and onto the LIDAR, caused by specific waves resulting from the shallow depth of the lake. We also had high values for the current strength of the photo detector, because water has a specific structure. We quickly defined all related problems. Every day during the expedition station measurements were taken at the same time that samples were obtained (about 30 per day). Samples showed a high correlation with the LIDAR data. Next, we attempted to calibrate MODIS data. The LIDAR was calibrated, and using this LIDAR data we worked out three specific regions. After that we tested the correlation between LIDAR and satellite data. These three days correlate poorly with the LIDAR data, because there were different atmospheric conditions every day. Nevertheless, data for each day correlated well. Examples of LIDAR data and satellite data for each day are presented and discussed.

 

Presentation. (Ref: CLIMSEAS2011_S10)

UdG, Girona. June 2011.


A Deterministic Model for Lake Clarity: Application to Management of Lake Tahoe (California, Nevada), USA
Joaquim Pérez, University of Girona
 

Perez3

Lake Tahoe (California-Nevada) is a deep ultra-oligotrophic, sub-alpine lake. Over the past decades, it has experienced the beginning of the early stages of eutrophication. The goal of this research is the quantitative evaluation of the application of coupled hydrodynamic, ecological and clarity models, to address the deterministic prediction of water clarity in lakes and reservoirs. The water quality model used is the Dynamic Lake Model - Water Quality (DLM-WQ).

Four specific objectives have driven this research effort toward achieving the goal mentioned above. The first objective was the implementation of new water quality and optical sub-models into the DLM-WQ. The water quality components reflect biochemical processes such as nutrient uptake and cycling, algae growth and zooplankton dynamics, and dissolved oxygen cycling. The optical component-derived Secchi depth and other optical parameters from absorption and scattering characteristics based on dissolved and particulate matter predictions from the other model components. The extinction coefficient, which is strongly dependent on the particle and chlorophyll concentration and size distributions, could be accurately estimated from the output of the DLM-WQ.

The second objective was to provide a calibration strategy based on a genetic algorithm technique. The third objective was to successfully validate the model. The model task is focused on reproducing the seasonal pattern and the proper trend of changes in the phytoplankton population, estimated as Chlorophyll a, and the nutrient concentrations, Secchi disk and other selected variables. The fourth objective was to describe, through simulation studies, the effects of different management and physical scenarios on the lake water quality and clarity.  

 

Presentation. (Ref: CLIMSEAS2011_S11)

 SIO, Moscow. June 2011.


Analysis of the extreme cyclones and storms over the coastal seas: application to climate variability and change in cyclone activity
Natalia Tilinina, P.P. Shirshov Institute of Oceanology RAS

 

Tilina

In our research we focus on the analysis of climate variability in atmosphere-related extreme events in the semi-enclosed seas of the Russian Federation, namely the Barents, Baltic, Black and Aral seas. In particular we concentrate on the extreme wind events over these seas associated with cyclone propagation in the domain. Extreme winds can lead to the extreme storms and disastrous winds and waves greatly affecting coastal and marine structures as well as marine carrier operations. In order to understand the mechanisms and quantify the genesis of extreme winds over the Barents, White, Baltic and Black seas we will use the archive of cyclone storm tracks developed at SAIL (Sea-Atmosphere Interaction and Climate Laboratory) of IORAS. This archive provides cyclone trajectories and associated parameters of the cyclone life cycle (cyclone intensity, deepening rates, propagation velocities, etc.) over the northern hemisphere and will be used to select specific regional cyclone sub-sets and to further analyse them. Since we have tracking results revealed from all presently available reanalyses, we use most advanced and high resolution products (such as NCEPCSFR and JRA25) to develop regional long-term climatologies of cyclone characteristics for individual basins.

From these sub-sets we select cyclone cases for the events of strong winds and will further associate the occurrence and characteristics of these cyclones with large scale circulation conditions. A major goal of the activity will be to develop robust statistics of cyclones that have the potential to cause extreme weather events over the seas. The project outcome will be regional data bases of cyclone trajectories and associated meteorological conditions as well as a statistical analysis of the time series for individual basins and an analysis of co-variability with large-scale circulation.

 

Presentation. (Ref: CLIMSEAS2011_S12)

UBRUN, London. June 2011.


New data on microfossils and rapid climate change on the NE Black Sea shelf during the Holocene and the last 150 years
Elena Ivanova, P.P. Shirshov Institute of Oceanology RAS
 

Ivanova

The major achievements of this study concern the evaluation of salinity changes on the NE and SW Black Sea shelves and the correlation of faunal and paleoceanographic changes between the two areas based on the calibration of the radiocarbon dates from the three cores on the NE shelf. Future work in cooperation with Russian colleagues from SIO RAS and ZIMB FED RAS is aimed at the detailed examination of ostracod and dinocyst assemblages on the NE shelf over the last 150-200 years in order to reconstruct the environmental changes that have occurred on the CLIMSEAS timescale. The study is supported by the age control using 210Pb and 137Cs measurements provided by Moscow State University.

  

 

 

Presentation. (Ref: CLIMSEAS2011_S13)

UBRUN, London. June 2011.


Breeze circulation over the Aral Sea: some results and future work
Valentina Khan, Hydrometeorological Research Centre of the Russian Federation

 

Valentina

Although the effects of desiccation of the Aral Sea on the environment are widely discussed in different publications, changes in the breeze circulation system are poorly represented. In the present study we discussed if is it still important to take into consideration the effect of the Aral Sea breeze circulation. Breeze circulation mechanisms were analysed on the basis of meteorological observations including pilot balloon observations at the western part of the Aral Sea. The pilot balloon observations were conducted during two comprehensive expeditions in October 2003 and August 2004 in the Uzbekistan part of the western Aral Sea basin. Along with PIBAL data, 1-3 hour surface meteorological data were obtained from the Aktumsuk meteorological station, located at a distance of ~7 km from the place where PIBAL observations were made and ~4 km from the sea shore. This station is a part of the WMO Global Observing System and performs regular observations in accordance with standard synoptic measurements. For the period of our campaign the PIBAL observations were conducted every 1-3 hours. Records of surface pressure, relative humidity, air temperature and wind were made every 10 minutes using automatic meteostation from the PIBAL observation site. The long-scale patterns to provide the background situation is briefly described using synoptic maps from the Hydrometcentre of Russia and NCEP/NCAR reanalysis data. Using special trigonometric equations and the measured time changes in balloon height, azimuth and elevation, we computed the speed and direction of the wind. Analysing vertical profiles of meridional and zonal component velocities of the wind, we described the strength, vertical extension, and diurnal cycle of the breezes caused by diurnal surface temperature contrasts between the sea and the surrounding terrain.

The main findings of this study can be formulated as follows:

1) The results indicated the presence of sea breezes with maximal development during the afternoon hours, around 14-16LT, with heights of ~1.5 to ~1.8 km and velocities of ~2.2 m/c2).

2) Land breezes with a depth of approximately 300-500 m. and low-level velocity of breeze flow reaching 1.5 m/s in the early morning hours were also depicted. The return flow of land breeze cell is not clear.

3) The breezes observed at the west of Aral Sea site in October 2003 are shallower than the ones observed in August 2004 due to smaller contrasts between sea and land.

4) The difference in the inland penetration of the breezes and their intensity is shown by comparing surface meteorological observations from two different locations: the Aktumsuk meteostation and the automatic meteostation. Differences in the amplitude and phase of the diurnal cycle of air temperature, relative humidity and wind at two locations due to different influences of sea-breeze circulation can be also affected by other local circulations patterns.

5) Although the Aral Sea has lost 4/5 of its volume, the effect of the Aral Sea breeze circulation is still essential and should be considered as an important component of local atmospheric circulation.

6) The obtained results can be useful to adjust regional climate models in order to present conditions in the study region.

 

Presentation. (Ref: CLIMSEAS2011_S14)

UdG, Girona. July 2011.


Hunting for river plumes: observations and modeling of ROFIs on the Russian Black Sea shelf
Peter Zavialov, Shirshov Institute of Oceanology RAS

 

seminari Peter 2011

The aim of this work is to study the dynamics of the Mzymta River plume and its interactions with coastal waters of the eastern part of the Black Sea. An array of in-situ hydrographic data was obtained during the recent expedition of the Shirshov Institute of Oceanology to the Mzymta mouth region of the Black Sea coast. The measurements were taken during the flood period on 25-30 of May, 2010. They included continuous records of the bottom layer velocity at four mooring stations deployed at the plume and the adjacent area, and similar records of the river inflow at the mooring station set at the river mouth. Also, meteorological data were collected at two coastal meteorological stations. The first station was situated near the river mouth and the second one was set near the southern edge of the plume extension about 8 km away from the first one. In addition to these continuously recorded measurements, everyday CTD top-to-bottom profilings at 5 stations were made, as well as continuous CTD measurements along the boat track using a shipboard pump-through system.

Based on these observations, a direct Lagrangian particle tracking model has been developed. The main goal of this transport model is prediction of the dispersal of river freshwater discharge. Prescribed arrays of the ambient sea current velocity, the river inflow and wind stress data together with the turbulence and the drag coefficients are the input parameters. The modeling program consists of three modules. The first module simulates the motion of individual freshwater particles using its Lagrangian tracking. After that the second module parameterizes and actualizes dissipation processes which affect the plume. Finally in the third module, the obtained distribution of all particles comprises the river plume as the result of the subsequent interpolation. This model simulates the dynamics of the plume spread generated by the Mzymta river inflow in the coastal waters of the eastern part of the Black Sea. Various parameters of this plume evolving out of different wind, stream and inflow conditions can be obtained and visualized using this model. As a result, the relations between the shape and other parameters of the river plume on the one hand and the main governing forces on the other hand were obtained"

 

Presentation. (Ref: CLIMSEAS2011_S15)

UdG, Girona. July 2011.


Possibilities of collaboration of Gilab within Climseas
Mateu Sbert, University of Girona

 

Mateu Estada

We focus our interest to five coastal lagoons in the Baltic Sea, namely the Darss-Zingst Bodden Chain (Germany), Sczcecin Lagoon or Oder Estuary, Vistula Lagoon and Curonian Lagoon, and Neva Bay. The last one is artificially recently made lagoon-type water body bordered by artificial dams. All of them could be considered as estuarine choked type lagoons. Definitions and typology of lagoons were discussed. The estuarine lagoons are the arenas of permanent mixing of the marine and river originated waters. There are two types of water (marine and river ones) which are experienced permanent transformation within the lagoon. But experimental fact is that water characteristics in a lagoon vary not continues (liner change between marine and fresh waters), but stepwise. And those compartments in a lagoon with individual characteristics bordered by local frontal zone. The examples for the Drass-Zingst Bodden Chain and Vistula Lagoon was presented. External factors influenced on mixing in lagoon was discussed. The mixing process as the process leading to originating of waters with intermediate characteristics is considered in hydraulics in two aspects:  mechanical exchange (steering) of considerable amount of water with given characteristics by another one due to external forcing leading to formation of intermediate spatially averaged characteristics, and further, (ii)  proper mixing as a final act of steering, when a water volume with individual characteristics becomes less than the sensor measured it (e.g. CTD sensor). Field measurements showed, that head of intrusion accompanies with eddies. Frontal divisions in different hydro-physical parameters are not coincide with each other. It indicates an existing of different rates of diffusion in a moving frontal zone around the head of intrusion. as one mechanism of mixing, the Langmour circulation was discussed. This attention was specially made in commemoration of Prof. Irving Langmuir and in occasion of his 130th birthday (31 January, 1881). The examples of hydrophysical measurements in Drass-Zingst Bodden Chain and Vistula Lagoon across the circulation pattern were demonstrated. The conclusions were: Rolls structure is developed after 5-10 minutes of wind starts blowing. The vertical scale of Langmour circulations in shallow waters are limited by depth. The processes of junction and disintegration of roles are in equilibrium, and Y-junctions of all 4 types are present.

In addition, the information about study of resuspension process in the Vistula Lagoon comprised from field measurements and analytical estimations on the basis of introduction of windness assumption was given. In conclusion the fact of level rise observed in the Baltic lagoons, attributed to recent climate change, was illustrated by data and discussed.

 

Presentation. (Ref: CLIMSEAS2011_S16)

RHMC, Moscow. July 2011.


Optical remote sensing of sea-waters
Vera Rostovtseva, P.P. Shirshov Institute of Oceanology RAS

 

Rostovtseva

Light in the visible range of the spectrum penetrates into water depths (from several meters to several tens of meters) thus giving information about the state of the upper layer of sea that is of great importance for life on Earth. Passive remote sensing methods use the sunlight illuminating the water surface and detect the signal from it in daytime. Active remote sensing methods use lasers to illuminate the water and can operate throughout the day, but need a larger energy supply.
Remote sensing of Atlantic Ocean, Baltic Sea and Black Sea waters from a ship was carried out using passive spectrophotometric and active fluorescence lidar lidar fluorimetry methods. The variability of the sea-water bio-optical parameters was estimated and compared to the distribution of hydrophysical parameters. Because of their confined nature and strong interactions with the continent, inland and marginal seas generally differ from the open ocean in the terms of optical properties, and often exhibit significant regional peculiarities. This is especially true for regions influenced by freshwater discharge.

Data from the passive spectrophotometer (Ro-meter) operated from on board a ship at a number of stations in the investigated aquatorium were used to reconstruct the brightness spectra of the sea radiance coefficient (brightness of the sea backscattering radiation divided by the brightness of the incident solar radiation). Using the admixture concentrations in sea-water samples taken at the same stations, we calibrated the spectra to estimate the chlorophyll, dissolved organic matter, and suspended matter concentrations. That allowed us to visualize the distribution of the sea-water natural admixtures in the area of interest and compare them to the satellite data.
At the same time, we obtained some active sounding data from the fluorescence lidar  operation from on board a ship at a frequency of 2 Hz, which gave high resolution maps of chlorophyll concentration in the study area. The observations were accompanied by CTD profiling and ADCP measurements. It was observed that while the radiance and fluorescence spectra are good proxies for fluvial discharges in the coastal sea, the mixing zones traced in that way do not always coincide with those inferred from physical hydrographic measurements.

 

Presentation. (Ref: CLIMSEAS2011_S17)

UBRUN, London. August 2011.


Estimation of surface characteristics obtained by a regional non-hydrostatic model: WRF-ARW
Roman Ignatov, Hydrometeorological Research Centre of the Russian Federation

 

RIgnatov1

Numerical experiments performed with the WRF-ARW model during July 2009 over the Aral Sea domain are presented and results are compared with experimental data from five meteorological stations. Results of the experiments were compared with objective analysis of NCEP data. Model temperature at two metres and surface temperature are closer to observation then objective analysis of NCEP data. Results of wind and sea level pressure at 10 metres are slightly worse than temperature when compared with the NCEP data.

 

 

 


 

Presentation. (Ref: CLIMSEAS2011_S18)

UdG, Girona. October 2011.


Comparison of the temporal spectra of the Aral Sea wind fields represented by stations, NOAA reanalysis and WRF forecast data
Vladimir Tischenko, Hydrometeorological Research Centre of the Russian Federation

 

tischenko

Analysis of the wind within the area adjacent to the Aral Sea is presented using the following data: observations made every three hours at three synoptic network stations located on the coast of the Aral Sea; CRFS reanalysis wind data with a spatial resolution of about 30 km (zonal and meridional components of the wind); and forecast data from the WRF model with fine resolution.

A clear diurnal variation was detected in the wind spectrum for the summer months (and often in spring and autumn). We have also analyzed the spectra of all available periods. This diurnal variation of wind can be associated with the breeze. The spectra of the modeled and observed wind data are very similar In addition, we have analysed the power of the spectra for reanalysis and forecast data in the study area. Maps of the power spectrum confirm the idea of having a breeze circulation in warm half in the south-east of the Aral Sea.

 

 

Presentation. (Ref: CLIMSEAS2011_S19)

UdG, Girona. October 2011.


Activity of Laboratory of General Circulation and Climate Change Modeling
Konstantin Rubinstein, Hydrometeorological Research Centre of the Russian Federation

 

KRubinstein2

The main lines of investigation in the laboratory are presented. They are: general circulation models of the atmosphere, short- range regional forecasting, urban meteorology modeling, comfort degree forecasting, polar region forecasting, dangerous meteorological event forecasting, new data assimilation and supplying meteorological data for some transport models. In the talk the tasks of all the investigators of the group are presented and main results are shown.

 

 

 

 

 

Presentation. (Ref: CLIMSEAS2011_S20)

UdG, Girona. October 2011.


Modeling circulation, turbulence and material transport in the sea
Konstantin Korotenko, P.P. Shirshov Institut of Oeanology RAS

 

KKorotenko1

Introduction and overview of hydrodynamic models and methods applied for predicting circulation, mesoscale structures and contaminant transport in the seas were made in the introductory presentation at the seminar.

Among the region of interests focused on were the Black, Caspian and Adriatic seas, the Gulf of Mexico, the English Channel and Taiwanese coastal waters. Among the problems discussed at the seminar were features of water circulation and generation of mesoscale structures in the Adriatic and Black seas. These seas are characterized by general basin-wide cyclonic circulation, surrounded by many predominantly mesoscale structures.

Marine turbulence modeling and a comparison of the results with those obtained with a high-frequency ADCP in the English Channel were discussed as well. The second-order closure turbulence model, including equations for the evolution of the kinetic energy, the rate of its dissipation and the Reynolds stresses, was discussed. The variance method was used to estimate turbulent parameters from the ADCP data.

Applied for the prediction of material transport in the marine environment, a Lagrangian particle tracking model was introduced and discussed with a special reference to original models for prediction of oil spill and larval transport and dispersal. Special attention was paid to a recent accident in the Gulf of Mexico. The Deepwater Horizon blowout in the Gulf of Mexico, from April 20 to September 19, 2010, was the largest accidental marine oil spill in the history of the petroleum industry. In conclusion, two versions (5- and 2-nautical minute horizontal resolution) of DieCAST implemented for study circulation and mesoscale structures in the Black Sea were presented along with some important results obtained in numerical experiments.

 

Presentation. (Ref: CLIMSEAS2011_S21)

UdG, Girona. October 2011.


Numeric forecasting of atmospheric characteristics with different description of Aral-sea area in WRF model
Svetlana Tkachuk and Victoria Byichkova, Hydrometeorological Research Centre of the Russian Federation

 

Previous studies (Byichkova V., Ignatov R., Rubinstein K.) showed that the forecast of basic meteorological fields using the WRF mesoscale model for the territory of the Aral Sea has some errors in comparison with station data, especially noticeable in the south-east of region. A comparison between satellite images of the area in the late 20th century and at present shows that the Aral Sea has decreased significantly. In this regard, it was decided to conduct an experiment on climatic "drying" of the Aral Sea. The results of the calculations were processed for July 2009. It was shown that an inaccurate description of the water surface in the model causes significant errors in the south-east region.

 

 

 

 

 

 

Presentation. (Ref: CLIMSEAS2011_S22)

UdG, Girona. November 2011.


Visualization a tool for divulgation and research purposes
Andrei Barcaru, University of Girona

 

Although nowadays 3D numerical simulations are rather common and experimental measurements in natural waters allow 3D representations, two-dimensional plots (horizontal or vertical sections) are still presented in limnological and oceanographic publications. However, tools exist for 3D representation of scalar variables considering threshold values of a transfer function to give opacity to the 3D field. In the case of the velocity field, given its vectorial nature, different scalar variables derived from the velocity have been introduced to track salient features of the flow. This is the case when velocity gradients can be combined to obtain different kinematic properties like the vorticity, divergence or the deformation rate. Alternatively, the shape or curvature of the instantaneous streamlines – their  geometrical patterns – can be used to identify salient flow structures. In this presentation, based in high resolution numerical data (<1 km), we evaluate the convenience of standard oceanographic parameters for the study of inland seas and lakes and study the potential of Shannon entropy as a new parameter for the identification of salient patterns. Based on this analysis, conditional entropy measurements are introduced to better identify different flow structures.

 

Presentation. (Ref: CLIMSEAS2012_S1)

SIO, Moscow. January 2012.


Circulation and thermohaline structure of the Aral Sea in the last three years
Alexhander Izhitskiy, P.P. Shirshov Institut of Oeanology RAS

 

The results of the three latest expeditions (2009–2011) by the Shirshov Institute to the Aral Sea are reported. We analyze the interannual variability of the basin circulation together with the thermohaline structure in order to identify the underlying mechanisms.

The study is based on the results of field surveys of August 2009, September 2010 and November 2011. The vertical profiles of temperature and salinity were obtained using a CTD profiler at six stations across the deepest part of the western basin in 2009 and 2010, and three stations in 2011. Additionally, during each of the surveys, mooring stations equipped with current meters and pressure gauges were deployed for 3–5 days in the deepest portion of the western basin. A portable automatic meteorological station, to continuously record the wind stress and the principal meteorological parameters, was installed near the mooring sites.

The vertical stratification exhibited a three-layered pattern, with local salinity maxima in the upper mixed layer and near the bottom, while the intermediate layer was characterized by a core of minimum salinity and temperature. Such a pattern persisted throughout the three years of observations.

Analysis of the current measurement data along with the meteorological data records demonstrated that the mean basin-scale surface circulation of the Large Aral Sea is likely to have remained anticyclonic, while the near-bottom circulation appears to be cyclonic. The current velocity and level anomalies responded energetically to winds. Correlation analysis of the velocity and surface level series versus the wind stress allowed quantification of the system’s response to the wind forcing as well as a formulation of a conceptual scheme of the lake’s response to wind forcing at synoptic temporal scales.

 

Presentation. (Ref: CLIMSEAS2012_S2)

UdG, Girona. February 2012.


Testing the Noah's Flood Hypotesis in the Black Sea
Lee Bradley, University of Liverpool

 

   The presentation focusses on the question of whether a catastrophic flooding event occurred in the Black Sea during the Holocene. I presented key diagrams from important papers that have addressed this question since 1997. I demonstrated that a number of viewpoints have been taken with some researchers arguing for a catastrophic flood and others arguing for a more gradual connection process. I finished by summarising work I have carried out using dinoflagellate cysts and ostracods and argued for a gradual reconnection process.

 

 

 

 

 

Presentation. (Ref: CLIMSEAS2012_S3)

SIO, Moscow. February 2012.


Scaling properties of the velocity turbulent field from micro-structure profiles in the ocean
Xavier Sanchez, University of Girona

 

Seminari Xevi Sanchez

We present a statistical analysis of the intermittent nature of turbulence. The nature of the intermittency is usually characterized using the scaling properties of the structure functions of the velocity or a scalar field, like temperature. Oceanic measurements with a micro-structure profiler allow the transverse velocity structure functions to be determined.  And following the refined Kolmogorov similarity hypothesis (K62), this scaling is directly related to the scaling of the rate of dissipation of turbulent kinetic energy .

In aquatic ecosystems, turbulent oscillations of various scales influence aggregation, incubation, and foraging processes of small-scale planktonic organisms. Internal intermittency can affect phyto- and zooplankton species less than several millimeters in size, and specifically the floating microscopic algae that are responsible for photosynthesis in coastal oceans. Zooplankton larger than 1 cm usually do not react to small-scale intermittency of turbulence. This is the first time, to our knowledge, that the structure functions come from space series. Previous results in air and in water were obtained from a static sensor in the atmosphere, the ocean, or in a laboratory setup. Furthermore, previous works were mainly focused on the longitudinal structure functions, while the results we present here are related to the transverse structure functions.

 

Presentation 1.  Presentation 2. (Ref: CLIMSEAS2012_S4)

SIO, Moscow and Kaliningrad. March-April 2012.


On the parameterization of shear-induced turbulence in a strongly stratified small reservoir  inferred  from upraising measurements
Jesús Planella, University of Girona

 

Seminari Jesús

Shear-induced turbulence plays an important role in stratified aquatic systems. It is a relevant mixing mechanism that leads to the vertical transport of nutrients, heat, and kinetic energy, into the water column. Small enclosed basins, wind stress, currents and also intrusions can be important sources of mixing and should be taken in account. Based on the diffusivity rates and focusing on the effects of river intrusion on a small and shallow reservoir (~23 m depth), we  analyze its possible coupling to other physical processes such as the internal seiches, wind stress and/or convection. In this type of system, shallow and stratified river intrusions lay on the bottom of the surface layer, which only occupies a few meters. Thus, we present the characteristics of a measuring system operated from earth used to obtain uprising measurements at 200 m from the shoreline and allowing the water column to be sampled up to the surface. The measuring profiler used in this system contained small-scale shear, fast-response temperature, and precision conductivity and temperature sensors, together with other optical sensors to obtain the chlorophyll and turbidity contents.

We present a series of 75 profiles measured with this device over a period of 22 hours during a night convective event. Data were recorded at the Boadella Reservoir in Catalonia, Spain, on 28 March 2010. High sampling rates and a slow profiling velocity allowed the small spatial resolution needed to resolve the turbulent scales and obtain several turbulent variables, including the dissipation rate of thermal variance and turbulent kinetic energy. During  the second part of the experiment, the velocity of the whole water column was recorded with an ADCP to evaluate the importance of the internal wave field responsible for the up and down displacements of the phytoplankton shown by our data and the strength of the river intrusion.

Applicable parameterizations of eddy diffusivity based on the Richardson number are tested in the river intrusion layer, where Ri numbers are very low. The parameterization proposed by Lozovatsky et al. (2006) for coupling between currents and internal waves is also tested. Based on the turbulent kinetic energy rate, a stratified dissipative patch is identified and the vertical diffusivity of the patch is parameterized following turbulent scales suggested by Lozovatsky and Fernando (2002). Results show good agreement between the values obtained from the spectral analysis, so we believe the information can be useful to improve empirical models based on the Richardson number.

 

Presentation. (Ref: CLIMSEAS2012_S5)

SIO, Moscow and Kaliningrad. March-April 2012.


Sea-level change and tectonics on the NE Black Sea coastline, Russia: processes and results
Stephen Kershaw, Brunel University

 

Field examination and literature study of marine terraces cut into bedrock (mostly Cretaceous turbidites) at various locations along the Russian sector of the NE Black Sea coastline were used to develop an understanding of the pattern of relative sea-level change in this portion of the coastline. Sea-level rise and fall throughout the late Quaternary Period produced a series of marine terraces cut into the bedrock at successive heights. Marine terraces are preserved due to an interplay between sea-level change and tectonic uplift of the Greater Caucasus Mountains, with a good match between marine events controlling Black Sea level and the global sea-level curve for the last 600 ka. However, questions remain about the ultimate controls of Black Sea level, because of imperfect correlation between marine flooding events and the global sea-level curve.

Results of this study show that in general the northern portion of this coastline is uplifting at a slower rate (ca. 0.1 mm/y) than the southern portion (ca. 0.2 mm/y) and that this is consistent with the orography of the Caucasus Mountains, which are higher to the south. However, it is also clear that variations along the length of Russian Black Sea coast suggest crustal flexure and/or fault control locally influenced the preserved sequences. Erosion of the weak bedrock (Cretaceous flysch) throughout at least the past few thousand years, along much of the coastline, has truncated old valleys in the bedrock, causing backstripping of the coast by (presumably) Holocene sealevel rise. This erosion is interpreted to have removed some of the more recent terrace evidence. The significance of this study is that it provides a synthesis of current knowledge of relative sea-level change in the Russian sector of the Black Sea coast. Crucially, tectonic uplift is likely to be the principal control on coastal processes; furthermore, coastal erosion along much of the coastline in recent millennia effectively masks information on the influence of recent climate change on this coastal section.

 

Presentation. (Ref: CLIMSEAS2012_S6)

SIO, Moscow. May 2012.


Implications of changes in the North Atlantic Oscillation (NAO) for climate in the Caspian Sea with a focus on sea level change
Maxwell McGuire, Brunel University

 

The background study for my master’s thesis at Brunel University is presented. The evolution of the level of the Caspian Sea, the North Atlantic Oscillation, and Artic Sea ice are reviewed. The principal objective is to investigate the possibility of a relationship between the Caspian Sea level, and climate change in the region, because controls on Caspian Sea level are not understood. This work will integrate modern data sets and older information, in an attempt to examine the climate changes across the area over the last 150 years, then the use of simple modelling of climate parameters in order to ascertain which parameter is the strongest indicator. In particular the potential influence of the North Atlantic Oscillation (NAO) and the changing situation across the Arctic region will be studied to determine whether or not these influence the Caspian Sea level. Datasets derived from the Shirshov Institute, and the Hydrometeorological Centre in Moscow and others, will be used to address the problem. Therefore this project will contribute to the CLIMSEAS programme directly.

 

Presentation. (Ref: CLIMSEAS2012_S7)

SIO, Moscow. May 2012.


The algorithm for the calculation of the long wave radiation fluxes in the atmosphere and dependence of the long wave fluxes upon cloud microphysical properties
Lidia Dmitrieva, Hydrometeorological Research Centre of the Russian Federation

 

Lidia 2012-seminari

Two-stream approximations are computationally efficient methods to solve the radiative transfer equation. Along with other applications, they are mainly used in atmospheric models to calculate radiative fluxes and heating rates at different levels within the atmosphere. Other more rigorous treatments are not suitable for atmospheric models because they require high computational effort. A two-stream method is presented, in combination with some approximations for the effects of the CO2, H2O and O3 absorbing bands, and for the Rayleigh optical depth. The solar band (0.2-4.75 micron) is split into 19 narrow bands to take into account the effects of the various atmospheric components. First the method is compared with a line-by-line Monte-Carlo approach for some specific atmospheric and geometric conditions. For a cloudless atmosphere, deviations for fluxes at the surface and the top of the atmosphere are within 1%. Heating rates for low atmospheric layers show deviations of about 0.1 K/day or less. Fluxes are also calculated for conditions with a stratiform cloud layer. Then, heating rates determined from Mie calculations and from a simpler parameterization are compared for various atmospheric layers.

In the second part of the seminar, the effect of variations in the cloud’s microphysical properties on the fluxes at the underlying surface is analyzed. Some conclusions are presented. In comparison with cloudless conditions, clouds diminish the surface balance (absorbed energy) on the 300-400 W/m2 range. The most important changes happen at the beginning of cloud formation when cloud water content (CWC) values are less than 0.15 g/m3. CWC contributes most to the cloud optical properties, as well as playing a major role in the cloud layer heating and surface radiation budget. A calculation error of 0.05 g/m3 in CWC leads to an error of 20-50 W/m2 in the radiation flux values and budget on the underlying surface. The diminishment of the surface and TOA budget in cloudy conditions in comparison with cloudless condition also depends on the mean values of the cloud droplet radius. The heating of clouds and the atmosphere shows small dependence on the mean radius values. Radiation budgets on the TOA and the underlying surface are the most sensitive to cloud microphysical property variations.

 

Presentation. (Ref: CLIMSEAS2012_S8)

UdG, Girona. May 2012.


Underwater sediment mass transportation as a geohazard factor: a unified model from the example of the Caspian Sea
Victoria Putans, P.P. Shirshov Institut of Oeanology RAS

 

Forest fires are natural disasters that spread fast, consume large tracts of territory, and are among the most influential factors in ecosystems. The occurrence frequency of forest fires can be bidirectionally connected with climate change conditions. To effectively prevent forest fires and their consequences, an effective system of direct and distant monitoring and a reliable prediction system to forecast fire risk are necessary. Wildfire risk and severity are the result of a combination of factors such as available fuels, physical setting, weather, and anthropogenic activity.

In this investigation, a long-range forecasting scheme of forest fire danger has been proposed. This approach is based on forecasted precipitation and temperature data from SLAV and CFS hydrodynamic models and the Nesterov index. To develop the forecasting scheme the climate snow cover information has been used. Instead of the traditional five classes of fire risk, three classes are proposed, namely “above norm,” “near norm,” and “below norm.” Verification results using hindcast data for six years were shown. The proposed scheme has been implemented by the Aerial Forest Fire Center of Russia. The fire danger forecasts are routinely used to outline an operational plan for the protection of resources from wildfires in different regions of Russia. Approaches to improve long-range forecasting of forest fire danger were discussed. Possible areas of investigation of the atmospheric effects of wild fires were proposed.

 

Presentation.  (Ref: CLIMSEAS2012_S9)

UBRUN, London. July 2012.


Calculating the Caspian Sea level from a water budget based on ECMWF interim re-analyses with the aim to make 6-9 months forecast based on ECWMF seasonal forecasts
Klaus Arpe, Brunel University

 

The hydrological budgets of the Volga Basin and the Caspian Sea (CS) are investigated by using ECMWF interim reanalysis (ERA) and seasonal forecast (FCST) data with the aim to predict the Caspian Sea Level (CSL) up to 6 months ahead. The available data are the precipitation (P) and evaporation (E) for the areas of interest. First the observed Volga River Discharge (VRD) and CSL are estimated using P-E data from ERA. To obtain from these the VRD, some delays due to the water entering the ground and flowing down the river, due to snow and ice and due to the storage of water in reservoirs along the Kama-Volga cascade are parameterized. For comparison the observations of the VRD and the CSL are used, the latter by sattellite or by gauge. Using initial data from the estimates by ERA, further 6 months based on seasonal forecasts and ERA data are calculated for each month from 1981 to 2010.

A general agreement between all data sets is found (anomaly correlations of 0.46 to 0.51) and there is some scope for making forecasts of the CSL few months ahead to allow for mitigating societal impacts. It turned out that only the seasonal forecasts of precipitation over the Volga Basin had a positive impact on the CSL forecasts. From 40 forecasts of more than 10 cm decrease of the CSL in 6 months (with a mean annual cycle removed) 14 are correct, 9 are still useful and 17 would have caused a false alarm, for increases of the CSL the values are 53, 16, 12 and 25 respectively.

Assuming that during long lasting periods of increases or decreases of the CSL, emergency meetings would have been held in cases with increases in winter and in cases of decreases in summer to decide on measures to be taken for the coming high or low stand in the following summer or winter respectively. Out of 7 cases investigated here the present scheme would have guided twice into the wrong direction and 5 times given good advice. A forecast assuming that the trend of the last 6 months will continue also for the next 6 months gives only 4 times good advice.

Also biases are found, e.g. the observed or simulated VRD would imply a CSL which hardly changes from 2001 to 2003 which does not agree with the observed CSL which shows a dip of 30 cm in that time. This disagreement can be assigned to uncertainties in the precipitation estimates over the catchments of the Sefidrud and Kura River in the ERA data. Some of the indicated problems may have been solved already in the present operational ECMWF analysis/forecasting scheme due to an increased model resolution and improved parameterization schemes.

 

Presentation part 1. Presentation part 2. (Ref: CLIMEAS2012_S10)

RHMC, Moscow. July 2012.


The Materhorn: Towards improving the prediction of mountain weather
Joe Fernando, University of Notre Dame

 

The prediction of weather in mountainous (complex) terrain remains a formidable challenge in physical meteorology. Flows in complex terrain consist of those due to diurnal thermal forcing (valley and slope flows) and to large-scale synoptic influence, which, when perturbed by terrain and land-cover variability lead to notable high-frequency phenomena such as trapped and propagating waves, flow instabilities, turbulence, wind gusts, flow pulsations, gap and separated flows, secondary circulation, intermittency, wakes and eddy shedding. The bulk of these represent (unresolved) sub-grid scale processes of meso-scale models, and hitherto no sound methodologies exist to parameterize the aggregate effect of such processes. The MATERHORN program was conceived in response to the Multidisciplinary University Research Initiative of the Department of Defense to address scientific issues that stymie the prediction of mountain weather. It aims to achieve rapid progress in predictability of mountain weather

The MATERHORN includes four major components: i) A modeling component that delves into mesoscale predictability aspects such as model errors, sensitivities to initial and boundary conditions, error growth, predictability limits, limitations of parameterizations and data assimilation methods. Ii) A comprehensive field experimental component  in the Granite Mountain Atmospheric Test Bed of the US Army Dugway Proving Ground; iii) A technology development component that develops new instrumentation, thus enabling the collection of flow, turbulence and moisture data over scales and footprints that are currently unachievable; and iv) A parameterization component  that helps improve subgrid parameterizations of mesoscale models, based on etiology and dynamics of processes delineated via high resolution simulations, laboratory experiments and field data.

 

Presentation. (Ref: CLIMEAS2012_S11)

UdG, Girona. July 2012.


Some results of 59th cruise of the Academic Keldysh to the Kara Sea
Peter Zavialov, P.P. Shirshov Institut of Oeanology RAS

 

This report presents some preliminary results from the 59th cruise of R/V Akademik Keldysh (Shirshov Institute of Oceanology, Russia) to the Kara Sea, which took place in the fall of 2011. The expedition focused on the interactions between the Arctic water masses and the extensive continental discharges from the Ob and Yenissey rivers. It was demonstrated that the area and pattern of the freshwater plume is highly variable at synoptic temporal scales, and also varies significantly at the interannual scale, based on a comparison with similar data obtained in 2007. We also identified four basic water masses in the upper mixed layer (Arctic Basin water from the St. Anna trough, Barents Sea water from the Karskiye Vorota Strait, Yenissey water, and Ob water), and showed that the entire variety of water types encountered in the surface layer can be produced by linear horizontal mixing between the water masses identified. Further, we presented a high resolution data set on the concentrations of suspended matter and chlorophyll-a in the upper layer, obtained by means of ultraviolet fluorescence lidar soundings along the ship’s path. We used this data set to investigate the characteristic scales for horizontal variability and patchiness of these parameters. We demonstrated, in particular, that the patch sizes for the total suspended matter and chlorophyll do not generally coincide, and are significantly anti-correlated in the domain of large patches. In general, the Kara Sea proved to be a good “model” for studying climate change effects in a marginal, nearly inland sea.

 

Presentation. (Ref: CLIMSEAS2012_S12)

UdG, Girona. July 2012.


Assessment of forest fire danger in the Russian territory using seasonal weather forecasts
Valentina Khan, Hydrometeorological Research Centre of the Russian Federation

 

Forest fires are natural disasters that spread fast, consume large tracts of territory, and are among the most influential factors in ecosystems. The occurrence frequency of forest fires can be bidirectionally connected with climate change conditions. To effectively prevent forest fires and their consequences, an effective system of direct and distant monitoring and a reliable prediction system to forecast fire risk are necessary. Wildfire risk and severity are the result of a combination of factors such as available fuels, physical setting, weather, and anthropogenic activity.

In this investigation, a long-range forecasting scheme of forest fire danger has been proposed. This approach is based on forecasted precipitation and temperature data from SLAV and CFS hydrodynamic models and the Nesterov index. To develop the forecasting scheme the climate snow cover information has been used. Instead of the traditional five classes of fire risk, three classes are proposed, namely “above norm,” “near norm,” and “below norm.” Verification results using hindcast data for six years were shown. The proposed scheme has been implemented by the Aerial Forest Fire Center of Russia. The fire danger forecasts are routinely used to outline an operational plan for the protection of resources from wildfires in different regions of Russia. Approaches to improve long-range forecasting of forest fire danger were discussed. Possible areas of investigation of the atmospheric effects of wild fires were proposed.

 

Presentation. (Ref: CLIMSEAS2012_S13)

UdG, Girona. July 2012.


Overview of numerical simulations performed on bottom-shear-induced gas transfer across the air-water surface
Jan Wissink, Brunel University

 

 For the numerical simulations that were performed of bottom-shear induced gas transfer a specialized numerical code, developed at Brunel University, is used to resolve the transfer of low diffusive gases (like CO2 and O2) from air into water. In nature three possible ways can be identified to enhance this transfer of gas to the main body of water.

The most effective mechanism is wind-shear-induced turbulent mixing, which will be dominant in non-sheltered bodies of water, like oceans and large seas.

In sheltered lakes, the cooling of the water at night can result in the second mechanism: buoyant-convection-induced mixing of the saturated water from the top and the non-saturated water below.

In flowing water (rivers etc.) the main source of turbulence is coming from below, where it is induced by bottom-shear. It is this phenomenon that was initially investigated experimentally by Herlina & Jirka and is presently investigated numerically by Herlina & Wissink. In the simulations, the bottom shear is modelled by isotropic turbulence that is prescribed at the bottom of the computational domain. The effect of both turbulence level and integral length scale on the mixing is investigated.

 

Presentation. (Ref: CLIMSEAS2012_S14)

ND, South Bend. July 2012.


Two years of the CLIMSEAS project: Initial results
Elena Roget, University of Girona

 

Although the University of Notre Dame (ND) was presented as a CLIMSEAS member at the University of Girona (UdG) in June 2010, only in 2012 is the program starting to be fully implemented at ND. After a short presentation of the project and of the UdG as the coordinating institution, the first scientific results obtained in collaboration with different groups participating in the program are reviewed in this talk.

Ten years (2000–2010) of cloud ground observations from 332 synoptic stations for the regions around the Black Sea, the Caspian Sea and the Aral Sea were analyzed. It was found that the larger summer/winter differences are found south of the seas, with the exception of some areas on the east coast of the Black Sea and western and southern areas of the Caspian Sea, where the reduction is less significant. The largest total cloud cover values are found in the northern section of the Black Sea. The effects of poor information about the cloud cover in the numerical simulations of lake hydrodynamics have been studied for several cases. Although sensitivity depends on many factors, a rule of thumb for medium and large lakes could be that a variation of one over ten in the cloud cover could affect by 10 W/m2 the sum of the latent and sensible heat flux plus the long-wave radiative flux.

Regarding the Black Sea, four paleoceanographic events during the Holocene have been identified based on the changes observed in fossil assemblages. On the other hand the Cold Intermediate Layer (CIL) – formed by fresh surface waters affected by the river inflow – has been studied. As a result, it is known that the winter cooling for a specific year is exhibited in the characteristics of the CIL for at least two subsequent years. The CIL’s mean temperatures for the 1982–1996 and 1997–2002 time gaps were, respectively, lower and higher by about 0.9°С than the mean temperature for the whole period of study, which corresponds to specific climatic events.

The response of the Caspian Sea to the drought of July–September 2010 has been studied to provide some scope for forecasting sea level variations a few months ahead to allow for mitigating social impacts. Regarding the Aral Sea, numerical simulations have shown that due to the decreased transversal area of the channel connecting the two lobes during the dissection period, high velocities have been generated in the channel by easterly winds. This flow has strengthened the erosion process at the bottom, which has deepened by about 8 m and will allow the saltier (~130 g/kg) and denser water from the eastern lobe to flow towards the fresher (~90 g/kg ) lobe for several years.

 

Presentation. (Ref: CLIMSEAS2012_S15)

ND, South Bend. August 2012

 


Holocene vegetation history and sea level changes in the SE corner of the Caspian Sea: relevance to SW Asia climate
Suzanne Leroy, Brunel University

 

The palynological investigation of core TM (27.7 m long) reveals both Holocene vegetation history in the NE foothills of the Alborz Mountains and past water level changes of the Caspian Sea (CS).
The delay in woodland expansion at the beginning of the Holocene, which is typical of eastern Turkey, the Iranian plateau and recorded in the CS south basin, is only weakly felt at the north-eastern foothills of the Alborz Mountains as the region is close to glacial refugia of trees.
The succession of the main trees out of their refugia has been established as deciduous Quercus, Carpinus betulus, Parrotia persica, and Fagus orientalis-Pterocarya fraxinifolia, presenting therefore close affinities to south European interglacials of the Early Pleistocene. This suggests a similarity in climate.
A differential Pterocarya decline is observed. The studied region is close to the easternmost tree distribution; this could explain why it has been affected earlier than elsewhere in the northern Alborz and the Caucasus. In addition human activities during the Sasanian Empire and the subsequent drying of the climate contributed to weakening the spread of this tree.
A maximum sea level occurs in the first part of the Holocene. It is suggested that the CS levels were significantly influenced by the monsoon precipitations over the western Himalayas. Finally it is recommended that the Neocaspian period should be considered a biozone rather than a chronozone as the environmental conditions reconstructed from dinocyst assemblages are different in shallow shelf waters and in the deep basins.

 

Presentation. (Ref: CLIMSEAS2012_S16)

SIO, Moscow. October 2012.


The effect of desiccation of Aral Sea represented by numerical experiments and observation data
Vladimir Tishchenko and Maria Smirnova, Hydrometeorological Research Centre of the Russian Federation

 

The effect of the desiccation of the Aral Sea on regional weather conditions was analyzed on the basis of model experiments using the Weather Research and Forecast (WRF-ARW) model at 5 km horizontal resolution and 28 levels in vertical until 50 hPa. Two model setups with different surface characteristics were used, namely “Aral” and “No Aral”. In the “No Aral” setup the water body was substituted by surrounding soil characteristics.

Two sets forecasts with lead times of up to 84 hours for July and January of 2009 were compared. The main focus of this study was to estimate the impact of the changing surface boundary condition on temperature, precipitation, cloudiness and wind. A comparison of monthly mean forecasts of surface air temperature, humidity, clouds, and wind in two types of experiments (“No Aral” and “Aral”) for January and July 2009 has been provided.

Preliminary results of this study have shown a significant difference between forecasted air temperature values represented by different experiments. In particular, the January “No Aral” surface air temperature is about 8-9ºC less than in the “Aral” experiments. For July, the “No Aral temperature is around 7-8ºC higher than it is in the “Aral” experiments. That means that the amplitude in this area with desiccation of the sea has been increased by 10-15ºC, and the climate has become more continental. Wind data from model experiments, reanalysis and station measurements has been analyzed using rose wind diagrams and temporal plots at the points of measured data. A clear diurnal variation has been revealed in the spectrum of the wind data taken from reanalysis and the “Aral” model experiments for the summer months. The presence of clearly defined peaks in the power spectrum in the southeast of Aral Sea region confirms the existence of breeze circulation reproduced by reanalysis and modeled “Aral” data. This means that the modle used in the reanalysis data has boundary conditions with consideration of the full Aral Sea.

Daily variations of breeze components of wind in points for forecast with Aral Sea and No Aral Sea in January and July show the influence of desiccation. In the “No Aral” forecasts, the amplitude of variation has become much smaller.

We compare the value of spectrum power corresponding to a 24h period (Q) in July for the “Aral” and “No Aral” experiments for different grids of the Aral Sea region. The spatial distribution of Q corresponding to the “No Aral” experiment is close to the structure of the Q fields represented by real data. In addition, an objective method of classification was applied to sea level pressure (SLP) daily data to reveal the typical structure of wind fields corresponding to different pressure field configurations. The three periods (the 1990s, when the Aral Sea had a larger area, 1997-2003 and 2004-2010) have been chosen for wind data. Different pressure field configurations were obtained using all periods of SLP data. It was revealed that for some types of SLP classes, the wind pattern changed significantly, especially for nighttime values of wind. In the early 1990s the average field of the wind near the Aral Sea was significantly different from the wind pattern of recent years.

 

Presentation. (Ref: CLIMSEAS2012_S17)

UdG, Girona. November 2012.


Global satellite sea surface temperature analysis: from climatic frontal zones to inner seas
Alexander Kazmin, P.P. Shirshov Institut of Oceanology RAS

 

Global satellite SST data (AVHRR MCSST and Pathfinder datasets (monthly mean for 1982-2009) along with the surface air temperature (SAT) and wind components from the NCEP/NCAR Reanalysis Project have been used to study long-term (quasidecadal) variability of the major large-scale oceanic frontal zones (OFZ) and SST field in the inner seas (Black and Aegean). For the first time, the global geography, climatology, and seasonal variability of the surface manifestations of all major climatic OFZ (subpolar, subtropical and equatorial) were obtained. For the first time, the existence of the long-term (quasi-decadal) variability of all major climatic OFZ in the world’s oceans expressed in variations of intensity (gradient SST) and meridional position of OFZ’s core was confirmed. Statistically significant correlations between the long-term variability of atmospheric forcing (meridional shear of zonal wind) and OFZ’s variability have been revealed. Long-term variability of SST in the Black and Aegean Seas has been investigated. It was shown that the large-scale atmospheric processes (NAO, EAWR) influence the variability of SAT and SST through the alteration of the heat flow into the area associated with the wind field variability.

Global satellite SST data (AVHRR MCSST and Pathfinder datasets (monthly mean for 1982-2009) along with the surface air temperature (SAT) and wind components from the NCEP/NCAR Reanalysis Project have been used to study long-term (quasidecadal) variability of the major large-scale oceanic frontal zones (OFZ) and SST field in the inner seas

 

Presentation. (Ref: CLIMSEAS2012_S18)

UdG, Girona. November 2012. 


Moisture affect on Diabatic Stability
Mercè Blanco, University of Girona

 

Turbulence within open canopies is shown to undergo a dramatic change during the transition from convective to stable conditions. In convective conditions the flow within the canopy is coupled through turbulent exchange to the flow above. As the transition advances, the flows decouple within and above the canopy, showing two different layers: a strong stable layer under the canopy and a less strong one above it. The stability condition may be disturbed by the existence of a large amount of moisture in the environment and particularly at the surface. Due to saturated conditions, an energy supply would be expected in the environment, conducted by the latent heat of phase change. This supply of heat could change the stability conditions due to diabatic cooling, forming two layers. But the lower layer, which is closer to the Earth’s surface, would be less stable than the layer above it. Answers to the moisture effect on the collapse of turbulent flows in the evening transitions and diabatic stability on the surface are presented.

 

Presentation. (Ref: CLIMSEAS2012_S19)

ND, South Bend. December 2012.


Studies on atmosphere and radiation in the Environmental Physics Group of the University of Girona / Some calculations of the aerosol effect in the retrieval of cloud optical depth from surface radiation measurements
Josep Abel González, University of Girona

 

The first part of the seminar was devoted to explaining current activities in atmospheric research in the Environmental Physics Group of the University of Girona, with the aim of synergizing collaboration within the framework of the CLIMSEAS project. Our activities are centered on the study of clouds, aerosol and radiation, their relationships and their climatology. Specifically, we are working on the retrieval of macroscopic cloud characteristics (total cloud cover, cloud vertical structure, and cloud optical depth) using different methodologies, the evaluation of the influence of aerosol in sunshine duration records, the comparison between measured and modeled radiation levels at the surface, both for solar and longwave bands, and the comparison between satellite cloud cover climatologies (ISCCP) and outputs from some GCM models. The latter activity could be very interesting for the CLIMSEAS tasks related to cloudiness.

The second part dealt with the retrieval of cloud optical depth and the estimation of the effective droplet radius from shortwave measurements at the surface (eventually combined with measurements from a microwave radiometer). A methodology based on some parameterizations of the relationship between atmospheric transmittance and cloud optical depth was presented. The potential effect of the atmospheric aerosol load and properties in the cloud optical depth retrieval was analyzed by means of (i) a simple two-stream treatment and (ii) a more rigorous radiative transfer scheme. The effect of the aerosol optical depth on the overestimation of the cloud optical depth can be very important, depending on the aerosol optical properties.

 

Presentation. (Ref: CLIMSEAS2012_S20)

RHMC, Moscow. December 2012.


Diagnostic of the troposphere-stratosphere interaction: sudden stratospheric warming events
Yulia Zyulyaeva, P.P. Shirshov Institut of Oceanology RAS

 

We analyse the monthly mean interannual variations in the zonal stratospheric circulation, three-dimensional Elliassen-Palm (EP) fluxes and their correlations with the sea surface temperature (SST) anomalies in the North Pacific and North Atlantic. The strong upward propagation of planetary waves from the troposphere to stratosphere over the northern Eurasia and the weak downward propagation in Labrador and South Greenland regions are indicated. There are large differences in the interaction of the zonal mean circulation and wave processes between the early winter (November-December) and mid-to-late winter (January-March). Amplification of the penetration into the stratosphere of planetary waves in December is strongly associated with changes of the stratospheric dynamics in January, creating of the “preconditions” for stratospheric warming appearances. It is shown that the “stratospheric bridge” with a strengthening of the downward propagation of the vertical EP flux over North Atlantic is being formed for years with the strong polar vortex. Simultaneous correlations of the stratospheric circulation variations with the Southern Oscillation Index showed its small linkage with the stratospheric dynamics in the Arctic. However, there are the significant correlations of the extra-tropical SST anomalies in the North Pacific and North Atlantic with the interannual variations of the stratospheric dynamics. The break of the Holton-Tan relationship during 1977-1996 corresponds to the positive phase of the Pacific Decadal Oscillation associated with the cold sea surface temperature anomalies in the Northwest Pacific. These findings hint on the strong impact of the decadal variations in the ocean temperatures on the planetary wave activity and on the stratospheric circulation during early winter, potentially realizing through the thermal forcing of the planetary waves.

 

Presentation. (Ref: CLIMSEAS2013_S01)

UBRUN, London. May 2013.


What do we know about the Black Sea history over the last 10,000 years?

Elena Ivanova, P.P. Shirshov Institut of Oceanology RAS

 

The Holocene paleoenvironmental development of the semi-enclosed Black Sea has received a great deal of attention due to its suggested catastrophic flooding by Mediterranean waters.

However, the amplitude and timing of reconnection between the Black and Mediterranean seas during the Holocene marine transgression has not yet been fully established. The seminar considers contradictory opinions about the timing and character of the reconnection between the two basins, notably hypotheses of catastrophic flooding, gradual transformation of a Neoeuxinian lake into a marine basin (“outflow” hypothesis) and stepwise immigration of Mediterranean species. The evaluation of the amplitude, character and timing of the Black Sea-level oscillations during the Holocene is of crucial importance to studies of regional and global change. However, such an evaluation strongly depends on the dating uncertainty and the regional stratigraphic framework. Several sets of micropaleontological (floral and faunal), geochemical and other time series data have been obtained during recent years, improving our understanding of the above-mentioned problems. Nevertheless, much more work, including the precise dating of the established paleoceanographic events, should be done to resolve the remaining controversies, in particular considering the species’ ecological preferences and coexistence of Caspian and Mediterranean species in the Black Sea during the early Holocene. To address the limits of the species’ ecological tolerance, the data obtained within the CLIMSEAS timescale (last 150 years) from the Black Sea shelf by the joint efforts of the Russian (SIO RAS) and English (Liverpool University) researchers are very promising.

 

Presentation. (Ref: CLIMSEAS2013_S02)

UBRUN, London. June 2013.


Analysis of station surface wind data in the Aral Sea region from 1991 to 2010
Elena Roget, University of Girona

 

Wind data at 65 stations located within the region between latitudes of 40ºN and 50ºN and longitudes of 53ºE and 67ºE were provided by the All-Russian Research Institute of Hydrometeorological Information-World Data Centre (RIHMI-WDC). Spectral analysis of the data recorded between 1991 and 2010 shows the relevance of the component of 24 hours whose amplitude is increasing in a large number of stations for the studied period during most of the year. However, for the present preliminary analysis, only the the August period was chosen.

It is observed that the wind power spectral density of the 24h wind component (24h PSD) ranges more than an order of magnitude and it is well correlated with the total PSD. There is not a minimum threshold of the total PSD for the existence of the peak of 24 and in some stations the sub-harmonic of 12h appears, which may indicate a breeze regime with different intensity between day and night.

Mean intensity of the 24h PSD was computed for the first (1991–2000) and second (2001–2010) decades of data, which cover an important part of the desiccation period of the Aral Sea. In general, it is observed that the 24h PSD around Aral Sea is increasing with the exception of the far north-western and south-eastern regions, where the 24h PSD slightly diminishes.

The increase in the region of the diurnal temperature range (DTR) could enhance the daily variability of the wind flow either directly or because it triggers secondary mechanisms like mountain or sea breezes. The most relevant increase of the 24h PSD is observed in the SW direction, which might already be affected by the Caspian Sea.

 

Presentation. (Ref: CLIMSEAS2013_S03)

RHMC, Moscow. June 2013.


Processes in the Black Sea: implications for climate change, past and future
Stephen Kershaw, Brunel University

 

Black Sea stratification is well known: the top ca. 100-150 m in contact with the atmosphere is mixed and oxygenated, forming a highly dynamic oceanographic environment. Publications by Russian oceanographers from the Shirshov Institute show that mesoscale and sub-mesoscale eddies form and disperse at regular intervals throughout the Black Sea upper waters, that have a salinity of about 18 parts per thousand (ppt). Below this mixed layer, the anoxic deeper water mass is more saline (22 ppt) and has deep water flow divided into two portions: east and west basins, with anticlockwise flow. There is also a circumferential current, the “rim current” that flows anticlockwise in the shallower parts of the Black Sea, and flows all around the margin in a single current. The redox boundary between the two layers is a zone of some metres thickness, and shows a decline in oxygen levels going downwards. There is not much mixing between these two masses, vertical movement of water is limited; instead the lateral (advective) motion is the major feature of Black Sea water, demonstrated by observation and modelled in calculations.

In the anoxic waters, pyrite framboids (clusters of octahedral pyrite crystals forming spheres ca.3-20 microns diameter) form by sulphate-reducing bacteria in the water column. These may sink to the sea floor and form an important analogue for ancient sedimentary rocks (hundreds of millions of years old). In older parts of the geological record, the abundance of black shales containing framboids has been used for some years by geologists to interpret anoxic conditions of those sediments. Thus deeper water sediments were commonly anoxic in much of geological history, and this is used to theorise that thermohaline circulation probably did not exist in its modern form.

 For this project, the particular occurrence of framboids is associated with the largest mass extinction in geological history, the end-Permian event; pyrite framboids are found abundantly in rocks formed in and after the extinction event, in shallow waters, and are interpreted to indicate an upwelling of deep waters bringing anoxia to the shelf environments, where most organisms live, and causing the extinction. This theory has been growing in recent years, but work by this author and others has revealed inconsistencies in the pattern of data. The key point is that numerous cases have been found of pyrite framboids in sedimentary rocks of the extinction levels which also contain abundant fossil shells, of benthic habit (ostracods and small gastropods are abundant). There are even reports of oolitic limestones (that form in maximum of 15 m water today) containing pyrite framoids. The coincidence of framboids, as evidence of anoxia, and of fossils and sediments, as evidence of oxygenated water, is inconsistent with the idea of rising anoxic waters and establishment of anoxia on the shelf. Thus in this project we turn to modern processes on the Black Sea shelf for analogues that might account for the inconsistency of the ancient sediments. The key aspect of this visit to Russia was to bring together information from scientists working separately, to try to provide a hypothesis from knowledge of the modern Black Sea. Publications record framboids attached to organic matter that form suspended masses in the anoxic waters, demonstrating that framboids do not necessarily sink to the sea bed as soon as they form. Publications by Shirshov Institute oceanographers show that the advective circulation can reach down into the anoxic zone. Publications by geographers, sedimentologists and palaeontologists at the Shirshov Institute reveal continuous instability of the shelf sediments, with frequent gravity sliding into the deep ocean down its slopes beyond the shelf-edge break. There is a lack of data concerning the interaction of the layered water with the physical margins of the Black Sea, but there is sufficient dynamism to promote a theory that some of the framboids could be brought up into the oxygenated upper waters and advected by mesoscale and submesoscale eddies, to be deposited in shelf sediments.

 

Presentation. (Ref: CLIMSEAS2013_S04) 

SIO, Moscow. July 2013.


Sea Level Change and the Oil Industry in the Caspian Region
Noel Healy, Brunel University

 

An introductory presentation was made on the topic of  the effect of sea level fluctuations on the oil industry in the Caspian region. Aim of the work is to examine how future climate change is likely to effect the oil indsutry. It will attempt to make reccomendations about how the oil indsustry should strategically plan to prepare for the effects of climate change.


 

 

 

 

 

 

Presentation. (Ref: CLIMSEAS2013_S05) 

SIO, Moscow. July 2013.


Cloudiness climatologies: studies for Europe and the Mediterranean and preliminary results for the CLIMSEAS area
Josep Calbó, University of Girona

 

Clouds are the main phenomena driving the radiative balance, both at global scale and also at local scale. Results of works carried out by the team at the University of Girona will be summarized. These include cloud climatologies for the Iberian Peninsula, Europe, and the Mediterranean region; both the mean behavior and the variability and trends are presented. The main data used are human-eye ground level observations of the sky, but sunshine duration records, satellite data, and reanalysis products are also used as complement. Most of these works clearly show the dimming/brightening phenomenon, which is influenced by the cloud decadal evolution and also by changes in atmospheric aerosol. The equivalent work that is being performed with data corresponding to the CLIMSEAS area (i.e., the Black, Caspian, and Aral seas region) will be presented too, including some preliminary results. The analysis is based upon cloud observations taken at more than 200 meteorological stations in the area. Cloudiness in the area shows a marked latitudinal gradient and also a strong seasonal cycle. In addition, during the two analyzed decades (1990-2010) some decadal changes are detected, in some specific regions and in particular for some seasons (autumn).

 

Presentation. (Ref: CLIMSEAS2014_S01) 

RHMC, Moscow. May 2014.


Intermittency of turbulence in natural waters
Jesús Planella-Morató, University of Girona
 

Turbulence in natural water bodies such as oceans, seas, lakes and reservoirs exhibits intermittent behaviour, in time and space, associated with strong fluctuations of turbulent energy dissipation and scalar gradients of scalars such as temperature, salinity and nutrients. As a result, turbulence intermittency is particularly relevant because it affects the transport of mass, moment and solutes in the water column and influences micro-scale processes such as ingestion rates, encounter rates of small-sized predators and their prey, and distributions of small-scale phyto- and zooplankton.

Characterization of the intermittency of turbulence is typically analysed through a statistical approach. In this way, statistics of turbulent quantities, such as the velocity field or the dissipation rates, are studied based on their statistical moments. In this talk, the structure functions of the vertical component of the velocity, which was obtained in a shallow tidal flow with an Acoustic Doppler Velocimeter (ADV), and moments of their squared-gradients (small-scale dissipation field) have been used to characterize intermittency.  The intermittency parameters have been obtained by fitting the scaling exponents to the multifractal and log-normal models. Results obtained using the velocity field, (structure function method), are in agreement with those obtained from the dissipation rate (trace and double trace method). For energetic episodes (high Reynolds numbers) the values of the intermittent parameters are shown to be close to those expected for fully developed turbulence. However, for relatively low Reynolds numbers the intermittency parameters deviate from the typical values, although can be attributed to the fact that ocean turbulence is not usually well developed. These results may explain the increase in small-scale phytoplankton patchiness when turbulence decreases and the changes observed depend on the phase of the tidal flow.


Presentation. (Ref: CLIMSEAS2014_S02)

ND, South Bend. November 2014.


Observation of significant variability in the field of sound velocity caused by inertial internal waves at the shelf of the Black Sea

Ielizaveta Khymchenko, P.P. Shirshov Institut of Oceanology RAS

 

 

In July 2011, during a 10-day measuring campaign being carried out from the MHI NASU platform in the Black Sea,  intense vertical oscillations of the thermocline were observed. These oscillations presented vertical displacements of up to 10 m or more and had a period close to a local inertial period of 17.2 h. These fluctuations caused a significant variability in the sound velocity of the sea water column, of which was registered every hour by minisound profiling. An interesting additional feature of the process observed was the shift of the quasi-inertial internal first mode oscillation into the second mode.  

 

 

 

 

 

Presentation. (Ref: CLIMSEAS2014_S03)

UdG, Girona. November 2014.