10. The climate change in low-Arctic seas: an attempt to estimate the substitution by two key planktonic species on the basement of physiological peculiarities and life cycle strategies
D. Martynova, N. Kazus', K. Mikhalchuk
11. Sources and delivery of sedimentary material to the central Arctic Ocean during the Pleistocene-Holocene (results from the organic-geochemical and lithological investigations)
V. Petrova, A. Kursheva, I. Litvinenko
The applied project aims to develop the criteria that specify the beginning and ending of navigation without icebreaker assistance in the northern seas. This issue is getting more and more pressing because of the observed warming tendency in the Arctic and sea-ice retreat in summer. At the moment there is no proper criterion that regulates the shipping in the Arctic seas. The former criterion was introduced many decades before and does not include some essential sea-ice characteristics such as presence of fractures and cracks etc. In the meantime new iceclass ships (scientific research vessels, tankers, dry-cargo vessels, container ships) with much enhanced technical properties have come into use. At the same time the climate changes over the Arctic lead to easier ice conditions and changes in sea-ice properties. A number of publications reveals the significant decrease in sea-ice extent, which also results in sea-route changes and a simplification of navigation. On the other hand new sources of information about sea ice cover (high-resolution satellite images, TV-complex etc.) provide the opportunity to create new criteria. Although navigation in the Northern Sea Route regions still strongly depends on icebreaker assistance, navigating without this support has become increasingly possible. The major goal of this research is to develop new criteria for modern ships and to specify the periods of navigation without icebreaker assistance along the perspective routes in the Barents and Kara seas with regard to present global climate changes in the Arctic.
O. Anisimov, J. Strelchenko, V. Kokorev
The main project objective is to develop an internet-based permafrost information system which will combine permafrost, soil, and climatic databases, models of different complexity targeted at predicting permafrost state and the impacts that thawing permafrost may have on the infrastructure in Northern Eurasia. To accomplish this goal we will:
- collect and analyze data on permafrost dynamics in Northern Eurasia (in close cooperation with the Permafrost group headed by Dr. Julia Boike at AWI Potsdam)
- identify the most vulnerable regions where trends in permafrost parameters are the strongest
- select appropriate methodologies, metrics and models to evaluate the impacts of changing permafrost (modern and projected for the future) on the infrastructure
- construct model-based predictive maps of geocryological hazards characterizing potential detrimental impact that changing permafrost may have on the infrastructure under the climatic conditions projected for the future
- combine the databases, models and maps into an internet-based information system with Russian and English interface
One of the research fields of the fellowship program "Changing Environments" is the study of recent and long-term changes in the Eurasian North. The observed global changes in climate and all the ecosystems are the object of interdisciplinary studies including oceanography, marine chemistry, sedimentology, paleoceanography and many others.
Our investigations will be focused on reconstructions of paleoenvironmental conditions and depositional processes in the central Arctic Ocean during Quaternary times. The proposed research will be based on the study of core sedimentary material to be taken during the "Polarstern" expedition 2008 (AMEX). Sampling should be performed on transects from the Canada Basin across the Alpha-Mendeleev Ridge into the Makarov Basin.
In this research we plan to investigate grain-size distribution, chemical (organic and inorganic) and mineralogical properties of the sediment sequences recovered from the ocean floor. Grain-size analysis and chemical analysis (major, minor and rare earth elements) are planned to be processed at the Otto Schmidt Laboratory (OSL). Mineralogical investigations are supposed to be carried out at St. Petersburg State University. Analytical investigations of inorganic chemical properties are supposed to be carried out at the Alfred Wegener Institute (AWI).
As a result the sources and pathways of sedimentary material and the environmental conditions in the time of its deposition and diagenesis will be determined.
P. Bogorodsky, A. Pnyushkov, M. Makhotin
The project is aimed at studying the ocean-atmosphere interaction mechanisms in flaw polynyas by the example of the Laptev Sea polynya. The overwhelmingly important result of this interaction is sea ice intensively forming on the polynya surface and thus an essentially changing energy and mass transfer between the two media. For the project purpose a variant of a onedimensional, nonlinear thermodynamic model of sea ice as a mushy (skeletal) zone will be elaborated. The model is to describe sea ice growth and its surface heat budget depending on seawater initial temperature and salinity, and changing atmospheric conditions. It will be based on heat and mass transfer equations and boundary conditions imposed at the upper and lower unknown moving interfaces of the mushy zone and take into account heat and moisture fluxes at the air-ice surface. The NCEP/NCAR atmospheric reanalysis data for the Laptev Sea polynya area and field observation data will be utilized in the model. The results of modeling will be applied for improvement of existing energy and mass exchange parametrizations and development of modern ones for the Arctic seas in regional and large-scale climatic models.
A. Ershova, O. Preobrazhenskaya
Sea ice is a natural habitat for so-called sympagic (ice associated) communities comprised of bacteria, fungi, algae and protozoans, as well as metazoans. The project focuses on the sympagic meiofaunal community. The main goal is to study the biological response of sympagic meiofauna to changes in the Arctic ice cover and to continue investigating the particularity of sympagic community of the Laptev Sea as a part of the Arctic ecological system. The plan includes ice sample analysis and interpreting the obtained results. These data are of large importance because investigations of the sea-ice meiofauna in the Laptev Sea haven been scarce (according to literature data). Special interest lies in the question whether there is any difference between the sympagic meiofaunal communities at the starting and at the ending point of the Transpolar Drift. The practical result of this work will be the enlargement of the common database.
I. Fedorova (supervisor), A. Charkin, A. Chetverova
This proposal combines two parallel investigations based on results obtained from expeditions to the Lena Delta: 1.) by the AARI, St. Petersburg State University, Alfred Wegener Institute, Pacific Oceanological Institute Far-East Branch of Russian Academia of Science and Stockholm University, carried out with the support of the OSL, RFBR, DAAD grant in 2004-2008, and 2.) the ongoing joint Russian-German and Russian-Sweden investigations on water, suspended, and dissolved substance runoff to the Laptev Sea. This combination allows enriching the database by new measurements and considered parameters and obtaining more information about suspended material and sediment processes in the delta.
The main project objective is to determine the transformation of suspended particular materials (SPM) and bottom sediment in the Lena River delta at full main channel length (from the central part to the coastal zone) on the basis of expedition data. The main scientific goals planned to solve in the course of our investigations are the following:
- to combine the data of the Russian-German and Russian-Sweden expeditions;
- to mark sections of the Bykovskaya Channel with intense bed movement or/and bed accumulation that have not investigated before due to lack of data;
- to determine the part of the Lena River delta (or coastal zone) with the highest speed of SPM dropping;
- to reveal the particularities of water, SPM, and bed-load sediment of the Lena River delta;
- to obtain more specific information about SPM and bed-load sediment of the delta parts with different erosion characteristics.
The water and bed-load samples, obtained during the 2002-2007 expeditions to the Lena River delta, will be processed at the OSL, AWI Potsdam, and POI FEB RAS in Vladivostok. Grain-size, geochemical, hydrochemical, isotopes, and TOC/TC analyses are available. This summer (August 2008) two expeditions to the delta and coastal zone are taking place. The project members are participants of these expeditions and, therefore, will have a lot of samples for such analyses. Using OSL equipment allows continuing the applicants' investigation.
Scientists from IFM-GEOMAR and AWI (Potsdam) have been working on scientific topics similar to those envisaged in this proposed project. Combining the German marine data with AARI and SPbU measurements from a central part of the delta, and the Vladivostok study at the channel edges will allow conducting the investigation using a greater amount of observation data with a higher level of confidence.
S. Kirillov, M. Makhotin, E. Bloshkina
The historical minimum in sea-ice extent over the Arctic was accompanied with considerable surface layer heating in September 2007. These conditions resulted in late ice freezing and, likely, less intensive ice growth during the following winter period.
The applied project aims to examine the variations in seasonal temperature and salinity changes over the southeastern Laptev Sea region based on the data mostly gathered during several Russian-German expeditions in 2007-2008. Our key goal is to establish the possible freshening in winter due to the heat accumulated in summer and, hence, the less intensive sea-ice formation and export to the Arctic basin in winter. This linkage was evident over the East Siberian and Chuckhi shelves during the second half of the last century and was associated with a decrease in sea-ice thickness and export since the 1960s.
The seasonality of thermohaline structures will also be examined to compare it with the historical records of seasonal cycle over the southeastern Laptev Sea and to figure out the changes that have occurred in the recent warm stage since the last century.
T. Kuznetsova, I. Chursina, E. Baikina
Mammoth steppe is a biotope remarkable for its unusual combination of mammal species. The ecosystem of the Mammoth steppe collapsed during the period of the Pleistocene-Holocene transition. Terrestrial permafrost deposits of the northeast Siberian Arctic shelf contain rich different records mirroring environmental changes in the Laptev Sea region during the Late Pleistocene-Holocene. Unique paleontological material, collected since 1998 within the framework of the Russian-German Cooperation "Laptev Sea System", allows us to reconstruct terrestrial ecosystems and their changes in detail.
The main goal of the proposed project is to trace the collapse of the Mammoth steppe ecosystem and its linkages with terrestrial palaeoenvironmental changes of the Laptev Sea surroundings (New Siberian Islands and mainland). It is based on the high-resolution analyses of Late Pleistocene and Holocene spore-pollen and ostracod assemblages and mammal distribution combined with geochronological, isotopic and DNA data. The research will be focused on:
- reconstruction of the terrestrial ecosystems in different regions of the Laptev Sea surroundings during Late Pleistocene-Holocene transition;
- determination of distinctions and time lags of collapse of the Mammoth steppe in the different parts of the Laptev Sea region.
All data on the Late Pleistocene-Holocene terrestrial palaeoenvironmental changes in this region are new.
A. Makshtas, R. Vlasenkov, A. Smirnov
On the basis of original field investigations and datasets created under the OSL projects (2006, 2007) as well as the historical data of the AARI, we plan to continue our study of radiation climate variability, suspended material and color dissolved organic matter (CDOM) distribution in sea surface, intermediate, and bottom layers of the Kara, Laptev, East Siberian, and Chukchi seas, and the adjacent parts of the Central Arctic Basin. We will use the data on suspended matter and grain size concentration, CDOM, and Secchi disk disappearance together with meteorological and oceanographic information. These data were obtained during expeditions to the eastern Barents, Kara, and Laptev seas, the western part of the East Siberian Sea and the adjacent part of the Central Arctic Basin in July-October 2007 and August-October 2008 within the framework of the International Polar Year. For our research the water samples which will be collected during the expedition of R/V "Ivan Petrov" in 2008 will be analyzed with the OSL instruments "Sedigraph" and "Specord-200". A modern database and three-dimensional maps of the parameters above mentioned will be compiled. Additionally the historical data of Secchi disc depth and water color observations, executed in the Arctic shelf seas in the 1950s to 1980s together with recent data will be used for estimating spatial distribution and temporal variability of light attenuation coefficients, single scattering albedo, and backscattering probability. The model of solar radiation absorption in sea surface layer under different cloudy conditions will be utilized for estimating the spatial-temporal variability of sea surface layer radiation heating in the study areas.
Finally, the long-term spatial-temporal variability of the characteristics above mentioned will be investigated in relation to regional climate change with a special attention to difference of sea water radiation regime in 2007 and 2008, the years with sharp distinction in sea ice and weather conditions. We plan to work in close collaboration with German scientists from IFM-GEOMAR, especially in investigations of the radiation regime in the Laptev Sea polynia region.
D. Martynova, N. Kazus', K. Mikhalchuk
We hypothesize that climate-induced changes in food spectra and reproduction period of the key planktonic species Calanus glacialis and Metridia longa may lead to trophic cascading and food web changes in the low-Arctic seas. The major objective of the present project is to assess the possible substitution of the large herbivore Calanus glacialis by the large omnivore Metridia longa under the scenario of climate change and to evaluate the impact of this substitution on the food web. The main investigations are planned in a low-Arctic isolated area (from 60 up to 343 m depth) - mostly Kandalaksha Bay, 66ºN 38ºE (WS). The present project includes:
- comparing the life cycle strategies of C. glacialis and M. longa in relation to hydrological data using the 50-years' database on hydrology and zooplankton dynamics in the White Sea (1957 to present);
- studying the feeding patterns of CV and adult females and hatching success of M. longa as well as respiration rates, on the basis of different food sources and light/temperature regimes with a series of experiments in the White Sea
The present project will combine field, experimental and data analysis approaches, with integration of these components as final publications and BSc defense, aimed at increasing our knowlegde in predicting changes in the Arctic pelagic ecosystems end-to-end.
V. Petrova, A. Kursheva, I. Litvinenko
At the present time we have the opportunity to compare data on the distribution of individual molecular markers in the bottom sediments of different geo-structural zones of the Arctic Ocean (the Lomonosov Ridge and Mendeleev Rise region) based on geochemical and lithological-stratigraphic data. Priority directions of our study are:
- comparison of basic organo-geochemical characteristics of the bottom sediments of the East-Eurasian continental margin;
- correlation between organo-geochemical and lithological-stratigraphic characteristics purposely for uncovering paleofeatures of sedimentation.
Expected results include geochemical-stratigraphic schemes reflecting the features of the Cenozoic sediments of the eastern high-latitude Arctic.
Ye. Polyakova, T. Klyuvitkina, L. Astakhova
The Laptev Sea polynya is a major area of sea-ice production in the Arctic Ocean, and it is one of the key elements of the environmental system of the Laptev Sea because of the high level of biological activity in this region during the spring and early summer time. The main goals of our proposed investigations within the framework of this proposal are the study of species composition and abundances of microalga communities (diatoms, dinoflagellates, chrysophytes, chlorophytes) in the ice cores and the upper water column, using sea-ice core and phytoplankton samples obtained during the TRANSDIFT XIII expedition to the Laptev Sea polynya area in April 2008. Sea-ice algae from three levels will be studied: bottom (10 cm), middle and surface layers, and phytoplankton will be studied from the water depths 1 m, 5 m, and 10 m. The following analyses will be carried out in this study as methodological basis:
- counting of total algal biomass and their species composition;
- detailed investigations of diatoms and dinoflagellates (living forms and cysts) as the major component of the Arctic sea ice and phytoplankton bloom during the spring;
- in order to be useful as an indicator of former sea ice conditions, a new chemical biomarker will be studied from the bottom sea-ice communities in combination with diatom records.
We suppose to reveal the regional peculiarity in species composition and productivity of sea ice algal communities and ice-edge phytoplankton in the Laptev Sea polynya area during the spring, and relationship between these two types of Arctic marine coenosis.
P. Semenov, A. Portnov, P. Serov
Sub-sea permafrost and processes in it are of great interest in the light of global climate changes. But for all that, they are extremely poorly studied on the western Arctic shelf, particularly the southwestern Kara Sea. One of the most interesting questions in this field is the interaction between submarine permafrost and gas emanations. It is well known that submerged permafrost can prevent gas migration into the above-lying sediments and water column. Thus, the gas constituents, containing methane as a main one, are buried under the ice layer. Consequently, in the zones of permafrost thawing there are favorable conditions for gas seepage and its final release into the atmosphere. The research work proposed comprises the following points:
- observation and mapping of submarine permafrost in the southwestern Kara Sea as a result of seismo-acoustic data interpretation;
- detection of gas-saturated sediments as a result of seismo-acoustic data interpretation;
- gas constituent analysis (common gas saturation of the sediment samples collected and composition of gaseous hydrocarbons of extracted gas samples);
- investigation of interrelation between gas saturation of the sediment samples and their grain-size content;
- study of correlation of the submarine permafrost distribution and gas-saturation of the sediments on the basis of geophysical and gas-geochemical data synthesis.
O. Semenova, I. Beldiman
Quantifying the influence of current climate and man-induced changes on land, surface water and energy fluxes is difficult in remote polar regions. Physically-based distribution models describing processes of terrestrial heat and moisture exchange can provide a means for investigating integrated processes and feedbacks. The permafrost zone still belongs to insufficiently explored territories with a poor monitoring network. Therefore, process studies strongly depend on observational data of rare and unique experimental sites. The analysis and use of such data in model evaluation and parameter assessment is an independent research task.
The parameters of the developed water and energy balance model will be evaluated on the basis of observational data of six experimental sites located in different permafrost landscapes of Eastern Siberia. Further simulation of subsurface and flow process at watershed scale will help to estimate the proposed model's abilities and robustness for process performance in permafrost conditions.
Data on thermal and hydrologic soil dynamics from the Lena Delta tundra observational site obtained and analyzed by the group of Dr. Boike (AWI) will become a part of informational database for closing the gap between small-scale process understanding and the watershed scale modelling.
The research will be conducted by two young scientists, one completing and another starting their PhD studies.
V. Shevchenko, N. Goryunova, D. Starodymova
We plan to study recent and long-term changes in the aeolian transport and fluxes of chemical elements and compounds (including pollutants) in the shelf seas of the Western Russian Arctic, Central Arctic and circumpolar flaw leads. We will estimate changes in delivery and accumulation of different types of particulate matter. A multidisciplinary approach and 4-dimension studies are necessary.
Our work will be focused on samples from the Eurasian Arctic seas and their catchment areas, Central Arctic Ocean, Amundsen Gulf (Canadian Arctic). We plan to study the composition of aerosols, snow, particulate matter, sedimentary matter from sediment traps from the Arctic Ocean, lake sediment and peat cores from the White and Barents seas' catchment area. We will compare our results of the Eurasian Arctic studies with our new analyses and literature data from the other Arctic regions.
This project could link ICARP II, SEDIBUD, Arctic Coastal Dynamics and OASIS and Circumpolar Flaw Lead (CFL) and other projects of the International Polar Year 2007/08 with active Russian-German cooperation.
E. Taldenkova, Ya. Ovsepyan, A. Strezh
In relation to the overall importance of a detailed reconstruction of interglacial marine environments and the water circulation pattern in subpolar and polar northern regions, the project is aimed at investigating past environmental changes and Atlantic-derived water inflows to the northern White Sea region during the Eemian (Boreal) transgression. In 2006 the 4.5 m thick marine sediment sequence directly overlying the Saalian (Moskovian) till in the Bychye section (Pyoza River, NW White Sea coast) was sampled for lithological and microfossil assemblage studies with 5 cm intervals allowing for obtaining a new detailed record of past events. Lithological characteristics (weight percentage of >63 µm, counts of lithic grains in the fractions 500-1000 µm and >1000 µm) provide evidence for the main features of sedimentation process and sea-ice cover extent. Fossil foraminifers and ostracods will be studied in the size fraction >63 µm. A special focus lies on the relative percentage of the species indicative of Atlantic-derived water inflow, freshwater influence, and sea-ice margin position.
The extent of Arctic sea ice has declined in recent decades and Arctic marginal seas are more vulnerable to further ice cover reduction. The Laptev Sea represents a significant source area of sea ice. The seasonal cycle of the Laptev Sea ice cover is of importance for sea ice budget and processes in the whole Arctic. The last description of the Laptev Sea ice regime was performed by Russian researchers in the 1970s; some points of regime were described by German researchers in 2005. But this regime should undergo significant alterations caused by recent climate change. The major purpose of the applied project is a detailed description of the main components of the ice regime in the Laptev Sea and the determination of their seasonal and multi-year variability during 2000-2008 to find possible shifts and changes in the sea ice regime. The following parameters will be analyzed by this project: terms of stable ice formation and break up, ice thickness, area of the polynya, fast ice, ice massifs, drift ice, and age structure. The main sources of data are ice maps compiled by the AARI. The data will be processed using the capabilities of spatial analysis of ArcGIS.