Marine copepods of the genus Pseudocalanus are common in waters throughout the northern hemisphere. They contribute considerably to plankton biomass and play an important role in the marine food web as a link between planktivores, such as fish larvae, and microalgae. Pseudocalanus consists of several sibling species, some of which look very similar and co-occur in certain habitats. In many studies on species distribution patterns they are referred to as Pseudocalanus spp. In the current MSc project we will use morphological, morphometric and molecular species-specific polymerase chain reaction (PCR) to achieve an accurate identification of the sibling species of Pseudocalanus co-occurring in the White Sea and in the Barents Sea. The latter allows us to describe distribution patterns, features of life cycle and the food strategy of these species.
N. Alexeevsky, A. Chetverova, L. Kuksina
This proposal is based on results obtained during expeditions to the Lena Delta by the Arctic and Antarctic Research Institute, St. Petersburg State University, Moscow State University and Alfred Wegener Institute for Polar and Marine Research, within the framework of projects supported by OSL in 2008-2010, and a DFG grant in 2009. It is a continuation of water and sediments research in the Lena River delta.According to the modern concepts the greatest part of suspended and dissolved components of river runoff does not reach the sea. These components are accumulated in delta areas and coastal zone. The assimilation capacity of delta ecosystems depends on the general regularities and regional characteristics of hydrodynamics, sedimentation and other processes. As a result of these processes a zone of transformation of geochemical runoff is formed. Thus, the study of hydrological and geochemical processes in Arctic delta areas is very important for understanding the evolution of the Arctic river ecosystems and their reaction on climate change and human impact. The results of the project could become a basis for further investigations of changes in geochemical characteristics and of the transformation of geochemical runoff in the Lena Delta through modeling.
E. Bazhenova, S. Kostygov
The proposed research will be focused on reconstructions of paleoenvironmental conditions related to the circumarctic ice-sheet history and depositional processes in the Amerasian Basin of the Arctic Ocean during late Quaternary times. Our investigations will be based on the study of core sedimentary material recovered during the ARK-XXIII/3 (Arctic-2008) Expedition onboard RV "Polarstern".We plan to use the OSL facilities to study 1) grain-size distribution in the sediments and 2) planktic and benthic foraminiferal assemblages. The obtained results can be used 1) to study the role of ocean currents, sea ice and iceberg transport in the sediment deposition and 2) to reconstruct the oceanic paleoenvironments (regime of the sea-ice cover, surface currents, influence of the Atlantic and Pacific water masses, bioproductivity). This study will contribute to the ongoing PhD project at the AWI. New results will be added to the proxy data produced at the AWI to be correlated with sediment-acoustic (Parasound) profiles, MSCL-logging and XRF-scanning records. A stratigraphic framework (age model) for the sediment cores is being established in cooperation with the whole geological group, working on the ARK-XXIII/3 material (at the AWI and cooperating institutions).
N. Bubenshchikova, M. Rimskaya-Korsakova
The reconstruction of variations of the oxygen minimum zone (OMZ) in the Okhotsk Sea during the Quaternary time is important for understanding the history of ventilation of the intermediate North Pacific and the global climate changes. We intend to reconstruct the OMZ intensity during four key intervals: the glacial terminations and subsequent interglacials 1, 5.5, 9.3 and 11.3 of core MD01-2415 by means of benthic foraminifera and the redox-sensitive trace elements in sediments. These interglacials were characterized by the highest marine productivity over the last 1.1 million years in the Okhotsk Sea in accordance with the core MD01-2415 biogeochemical data. It makes these intervals particularly suitable for studying the pronounced intensification of the OMZ in the past.We will compare the resulting paleoreconstructions of the OMZ intensity with variation of the solar insolation in the Northern Hemisphere and global sea level. This will provide insight into the driving force of the climate changes of the Okhotsk Sea environments during these four key interglacials. The IMAGES core MD01-2415 was collected on the northern slope of the Okhotsk Sea during the WEPAMA 2001 cruise of the R/V "Marion Dufresne". The trace element measurements will be performed by using the equipments of the OSL and the Laboratory of geochemistry IORAN. The planned study collaborates with the German-Russian research project KALMAR.
L. Frolova, L. Gafiatullina
In the course of global warming it is assumed that the boundaries of ecozones and species habitats relocate toward the north. However, due to the geographic distribution of continents and ocean, arctic ecosystems will almost disappear under strong climate warming. Cladocera fossil assemblages in lacustrine sediments are increasingly important for reconstructing past ecological and climate change, as these organisms are diverse, sensitive to limnological and climatic conditions and represent different compartments of lake ecosystems. Furthermore, the remains of these organisms preserve well in lake sediments, are identifiable and they are, therefore, valuable indicators of past environmental change.The purposes of this research will be to examine Cladocera assembles (contemporary and sub-fossil) from 55 northern lakes and ponds, to determine how invertebrates are distributed within the region with regards to environmental gradients and to reconstruct past environmental variables and past climate change using sub-fossil Cladocera remains. Our study is directed towards developing an empirical model based on the relationships between Cladocera taxa and abiotic variables (e.g., water chemistry, climate variables, etc.), particularly in terms of species optima to a measured variable. This inference model can then be used to reconstruct past changes of the abiotic variable of interest.
V. Ivanov, P. Maslov, E. Chernyavskaya
Dramatic changes in the state of the Arctic sea ice between 2004 and 2008 led to prevailing of first year ice (66%) over multiyear ice (34%). This change is generally in line with the GCM-based prediction of a shift towards a seasonal Arctic ice cover within several decades from now on. In recent studies it was shown thatthe retreat of the summer ice edge enhances shelf-basin exchange due to upwelling events in summer and cascading events in winter. Historical and recent observations in the Laptev Sea suggest that onshelf intrusions of Atlantic Water (AW) may significantly alter hydrographic properties, making the bottom water on the shelf warmer and saltier. Taking into account the continuous retreat of the summer ice cover, accelerated after 2007, we may expect a strengthening of the favorable background conditions for intensive shelf-basin exchange of water and properties in the future. We propose to examine the range of the possible effect of changing ice conditions on shelf-basin exchange in the Laptev Sea in the regional model study. To achieve this goal, we will carry out a set of year-long numerical experiments forced by typical atmospheric scenarios. The major outcome of this project will be a quantitative prediction of shelf-basin exchange in the Laptev Sea in a warmer climate.
E. Ivanova, E. Ovsepyan
High-resolution multi-proxy study of the last glacial-to-Holocene interval in the 18-m-long piston core SO201-2-85KL by our team in cooperation with the German partners provides reconstructions of the so far poorly investigated paleoenvironments of the Shirshov Ridge, western Bering Sea. We demonstrated the significant changes in bioproductivity, planktic and benthic foraminiferal assemblages, IRD supply to the seafloor and bottom water ventilation on glacial-interglacial and millennial scales. The present proposal is aimed to evaluate the difference in the last and penultimate glacials and interglacials, i.e., between the time intervals 5-50 (MIS 1-3) and ca. 115-150 kyr (MIS 5.5-6.1), respectively. The samples available for our proposal and preliminary stratigraphy, provided by the German partners, ascertain that core SO201-2-KL85 allows us to obtain substantially new high-resolution paleoceanographic results on the penultimate glaciation and Eemian interglacial, notably on surface and bottom water conditions and faunal assemblages. The resolution of the study has to be higher than in the eastern part of the Bering Sea where new ODP sites are currently being investigated. This will ensure a modern level of research, provided by a close cooperation with the German partners from AWI and the IFM-GEOMAR and by use of the OSL equipment. As the average sedimentation rate in the core is about 10 cm/1000 years we expect to compare the millennial-scale climatic variability during two glacial-interglacial intervals at site location, including two terminations. The recent results obtained by our team show some specific features in benthic and planktic foraminiferal assemblages on the Shirshov Ridge as compared to the assemblages from the Bauers Ridge, Sea of Okhotsk and other North Pacific locations. We intend to investigate the persistence of these differences and of corresponding paleoceanographic changes on the longer time scale by correlation of our data with the available results from both neighboring and remote marine and terrestrial records.
D. Karelin, G. Kraev, A. Pochikalov
Conventional techniques of measurements of the net carbon flux, gross respiration and gross primary production (GPP) in terrestrial ecosystems allow estimating major C-fluxes. However, this provides no insight into the role of below- and aboveground parts of the vegetation cover, or the dominant species or principal compounds input. These characteristics are crucial in local and regional-level assessments of the carbon balance. To reveal them gravimetrical studies together with chemical composition analysis might be used. Chamber techniques and gravimetric methods combined support the disclosure of the rates of "hidden" productive and destructive fluxes. The new data on plant matter decomposition will improve existing model estimates of the carbon balance in the tundra.
Bottom sediments are one of the main components of marine ecosystems. They are capable of accumulating and storing the information on status and changes of geochemical, dynamic, climatic, neo-tectonic environmental conditions, and of processes of mass transfer, including caused by anthropogenic impact.The project's purpose is to study the bottom sediments on key sites of some northern seas (the Chukchi Sea, the Barents Sea and the Baltic Sea) for estimation of the dependence of granulometric, geochemical, mineralogical structures of surface bottom sediments of the studied seas and distribution of types of bottom sediments on natural and anthropogenic factors. The possibility of reconstruction of sedimentary conditions on the basis of geochemical data is determined by the existence of a close connection between the geological processes causing accumulation of sediments and by distributions of concentrations of chemical elements in sediments. The change of geotectonic, climatic, hydrochemical and other conditions of sedimentation are reflected in the corresponding changes of the geochemical features of the formed sediments. The results of the project will be included into the applicant's PhD thesis, will be presented at conferences and published in reviewed journals.
The goal of this PhD thesis is to study polycyclic aromatic hydrocarbons (PAH) in marine environments. For this we investigate PAH origin, formation and input into the environment, transport processes, deposition and accumulation, atmospheric and water transport mechanisms, and transformation processes. Important objectives are to study PAHs in bottom sediments of the Arctic shelf and the accumulation and effects of PAHs on marine organisms.
T. Matveeva, A. Krylov, E. Logvina
Ikaite (CaCO3.E6H2O) is a metastable carbonate mineral which forms in cold, saline marine waters in anaerobic, organic-rich periglacial and glaciomarine environments near 0°C. In this work we plan to study ikaite as an authigenic mineral phase that probably records an episode of methane release from sediments in the Laptev Sea. The aims of the study are to reveal the origin of the carbon in the obtained ikaite samples and to estimate the role of anaerobic oxidation of methane (AOM) and gas-hydrate decomposition in its formation. According to the present knowledge, the ikaites may hold important clues for understanding the global carbon cycle and long time climatic changes. The stable isotope analysis (δ13С and δ18O), XRD measurements, and microscopy observations of the carbonate phase will be applied for achieving the objectives of this project. As an outcome of the project we plan to prepare and submit for publication in the international peerreviewed scientific journal an article entitled "Ikaite in the bottom sediments of the Laptev Sea: role of anaerobic oxidation of methane as a source of carbon for its formation".
This project will study the 141.5-m-long permafrost core collected from Lake El'gygytgyn crater jointly with German colleagues in November-December 2008. This field campaign was the first phase of the international "Lake Elgygytgyn Deep Drilling" research project. The objective of the project is to study grain size and TOC analysis of particular samples of the D3 core. It is intended to apply image analytic methods to provide a more detailed lithological description. We will try to find some indicators of facial changes in the deposits (e.g. subaquatic/subaeral sedimentation conditions). This will help us to make a correlation with the known change curve of lake level to link our core intervals to the regional stratigraphic scale.
Ye. Polyakova, I. Kryukova, N. Man'ko
Our researches are planned as continuation of the phytoplankton studies in the Laptev Sea which we carried out within the framework of OSL projects (2009 and 2010), and will focus on spatial distribution of different algal classes (diatoms, dinoflagellates, chrysophytes, chlorophytes), species composition and biomass of algal communities in the autumnal (September 2008) phytoplankton, and the comparison of contribution of different algal groups and species to phytoplankton biomass at the beginning and the end of the productive periods of 2008. Distribution patterns of algal communities will be compared to the measured hydrological parameters (temperature, salinity, oxygen, nutrients concentrations, chlorophyll a) in the water column. Special attention will be paid to the occurrences of freshwater diatoms and green algae in phytoplankton assemblages as indicators of the Lena and Yana river outflow to the studied area and spreading of river waters on the south-eastern Laptev Sea shelf during April-May and September 2008.
L. Savelieva, P. Vakhrameeva, D. Titova
The goal of this project is to create a Photographic Atlas consisting of the most widespread plants in the modern vegetation cover of the tundra zone within the Lena Delta, which are widely represented in Quaternary deposits from the Arctic region. By the present time atlases with photos of pollen and spores for the European part of Russia, Europe, Europe and the North Africa, etc. have been published. However, a similar Atlas for such an extensive area as the Arctic region of the Eurasian continent does not exist. It is necessary to notice that such a spore-pollen catalog is a basis for correct identification of fossil pollen and spores in this area. Besides, the tundra zone has a rich variety of grassy plants which produce a large quantity of pollen. Now the palynological study of deposits from this region is based on determination of limited quantity of fossil pollen of grasses. This is due to the different quantity of produced pollen, different stability of pollen exines to conditions of fossilization, etc., as well as the absence of a considerable quantity of photos of modern pollen and spores. However, this last circumstance is very important for the Arctic region where researches of palaeoclimatic changes are carried out applying the spore-pollen analysis. Detailed determinations of pollen and spores and findings sufficiently higher numbers of fossil pollen and spore taxons will allow restoring more precisely and in detail the biodiversity of fossil flora. In this regard the proposed Atlas of pollen from the Lena Delta will be the first step for composing the full and exhaustive Atlas of the flora of the tundra zone within the Arctic Eurasian region.
O. Semenova, L. Lebedeva, N. Kotova
The hydrologic cycle affects both the terrestrial and aquatic systems and is intimately coupled with the atmospheric system. The hydrology of the Arctic drainage plays an important role in the Arctic climate because the river inflow is one of the principal sources of freshwater and crucial for the maintenance of the Arctic halocline. One of the key unresolved issues of climate change in the Arctic is how the Arctic hydrological cycle responds to global change. There is a compelling need to understand the impacts of the changing basin-scale heat-water regimes on river streamflow in the Arctic on the large scale.The goal of the project is to assess the possible impact of climate change on the annual, seasonal and extreme runoff characteristics of the main source of freshwater in the Laptev Sea, the entire Lena River basin with an area of 2,430,000 km2, using various scenarios of climate change.
I plan to study the role of aeolian transport of chemical elements and compounds (including black carbon and pollutants) in the Arctic Ocean and surrounding land. A multidisciplinary approach is necessary. My work will be focused on samples from the Eurasian Arctic seas and their catchment areas and the Central Arctic Ocean. I plan to study the composition of lichens, snow and aerosols from the Russian Arctic sea catchment area. I will compare our results with literature data from the other Arctic regions.
Northern peatlands and permafrost associated with large soil carbon stocks are responsible for a high proportion of natural methane emissions. Rising temperatures will affect the carbon balance of high latitude ecosystems, but to what degree is uncertain. A great number of the peatland permafrost ecosystems concentrate in the Lena River delta region. Methane emissions from permafrost peatlands of the Lena River delta region can be intensified by the Arctic regional climate change and affected by the positive feedback of the climate system. The main goal of the project is to study the dynamics of the active layer depth, water table position and vegetation in the peatlands of the Lena River delta region using the Lund-Potsdam-Jena: Wetland hydrology and methane (LPJ-Why-Me) global vegetation model with the aim to explore possible effects of future regional climate change on the Lena Delta ecosystems. It can improve the quantitative predictions of the feedback of Arctic carbon pools to climate change.
E. Taldenkova, A. Stepanova, Ya. Ovsepyan
The project deals with the reconstruction of the Late Glacial to Holocene environmental history of the eastern Laptev Sea continental margin in the context of regional changes and overregional climate variability based on high-resolution records of lithological characteristics, IRD, benthic and planktic foraminifers and ostracods from AMS14C-dated marine sediment cores PS2458 and PS51/118-3. Core PS2458 dates back to >14.3 cal.ka, and core PS51/118-3 covers the entire Holocene since 11 cal.ka, with especially high resolution in the 9-11 cal.ka time period. The main issues we are going to address while investigating these cores and comparing the obtained results with the evidence from the western Laptev Sea are: i) eastward propagation of postglacial inflows of Atlantic-derived waters along the Laptev Sea continental slope; ii) peaks in IRD input during the Late Glacial and Late Holocene (Neoglacial) and the contribution of the local material from Severnaya Zemlya; iii) 13 cal. ka freshwater event in the Arctic and iv) the Early Holocene thermal maximum and its manifestation in the high-resolution centennial-scale records from the Laptev Sea continental margin.
The extent of Arctic sea ice has declined in recent decades. Variations of sea ice thickness are sensitive indicators of climate change. Different sources of data are used for these investigations. However, the period of instrumental observation is much too short to determine any significant ice thickness trend. The Laptev Sea represents a significant source area of sea ice. Changes of ice thickness in the Laptev Sea are of importance for the sea ice budget and ocean-ice processes in the whole Arctic. In the frame of the Soviet-Russian expedition "Sever," ice thickness measurements by drilling were carried out regularly starting in 1948. Annual data with a large amount of working points in the Laptev Sea were collected beginning in 1969. During the OSL project 2010 an estimation of multiyear sea ice thickness variability in the Laptev Sea by data obtained during the expedition "Sever" for the period 1968-1990 was carried out. The major purpose of the applied project is to find out whether there is a correlation with atmospheric circulation and hydrological processes. It holds much importance for understanding recent changes in the ice cover regime. Data of "Sever" expeditions are retrieved from paper already and prepared for digital usage. During the project, the data will be processed using the capabilities of spatial analysis of ArcGIS, Surfer, etc.
In recent times, humanity is faced with dynamic changes in climate. These changes are becoming apparent in high latitudes. The ice mode variability of the fjords is strongly associated with climate variability; it is formed under the influence of a large number of external factors, such as changes of temperature and salinity conditions of waters, precipitation mode, temperature and radiating mode of atmosphere, and the intensity of continental drain. In turn, the variability of ice characteristics, through the mechanism of feedbacks, influences the conditions of the sea and atmosphere as well. Thus, the research of ice mode can be considered as significant indicator of climatic changes. The researches of an ice mode, degree of its interrelation and interdependence to other elements of the geographical cover underlie the understanding of processes of climate changes of the region as a whole, and, therefore, are important.The goal of the PhD work is the research of the ice mode of the West Spitsbergen fjords, in connection with a number of "external" factors, and as significant indicator of climate variability. In accordance with the goal the key objectives are the following: - to collect data of ice conditions and atmosphere parameters in West Spitsbergen and analyze them (NPI and ROSHYDROMET sources and data collected during the field research); - to estimate the basic trends of meteorological and ice characteristics long-term variability.