2. Long-term variability of environmental properties on the Laptev and East Siberian shelves caused by the recent changes of the large-scale atmospheric circulation over the Arctic
S. Kirillov, M. Makhotin, A. Novikhin
5. Seasonal and multiannual variability of the ice cover in the southeastern Barents Sea and southwestern Kara Sea based on shipborne and remote sensing data (SSM/I, AMSR-E)
Ye. Mironov , T. Alexeeva , A. Timofeeva
10. The offshore permafrost evolution in the Laptev Sea after the Holocene transgression: a combination of the high-resolution seismic and onshore drilling approaches
P. Rekant , V. Tumskoy , P. Khasanov
E. Abramova, I. Vishnyakova, A. Gorodinskiy
Processes occurring in the pelagic fauna of the Laptev Sea shelf have been studied based on the analysis of samples obtained in different parts of the shelf during 14 years of investigation (1989-2000, 2003, 2004). Copepoda appeared to be among the most taxonomically diverse species in this region. The copepod community is clearly dominated by small brackish-water and neritic copepods tolerant to a wide salinity range, but usually preferred a salinity of less than 30. All these species, however, were also found on the continental slope of the Laptev Sea in the arctic surface water layer with salinities of more than 33. If these crustaceans were brought into the deep-water regions of the sea with surface currents, we do not yet know. Our understanding of their ecology and natural habitats is not complete. It is possible that during the last years the natural habitats of these ecologically flexible species have been extending due to climate changes in the Arctic, such as reinforcement of the wind and wave activity caused by air temperature rise, decrease in sea-ice extent, changes in temperature-salinity characteristics, increasing of river runoff etc. The main aim of the present study was to investigate the composition, distribution, population structure and ecology of small copepods from the wide shallow shelf of the Laptev Sea to the slope region to provide the background for further assessment of ecosystem variability connected with climate changes in the arctic regions.
S. Kirillov, M. Makhotin, A. Novikhin
At the moment our planet goes through a period of fast climatic changes that are evident in the natural environments and can strongly affect human activities. These changes are well expressed in the polar regions, which are traditionally more sensitive to all environmental shifts. These changes are evident in earlier ice melt and additional heating of the surface water through solar radiation and, hence, it leads to more intensive thermal degradation of the coastline and shallow areas of the Siberian Arctic seas. The influence of this heating on the greater depths depends on the river plume, which insulates the colder deep waters from the mixed surface layer. Howether, long-term climate variabilities may also affect the bottom waters and result in thermal degradation of the vast submarine cryolithozone in depths below the pycnocline, thus enhancing the positive feedback of warming through greenhouse-gas release. Preliminary results show a considerable coherence between the integral heat content of the Laptev Sea bottom layer and the large-scale atmospherical circulation in the Arctic even in winter. It was also found that warmer Atlantic waters cannot cause this correlation. In this project our aim is to determine the influence of the global atmospheric wind pattern on the hydrological regime of the deepest shelf waters. Therefore, we plan to compile and analyze the hydrological and hydrochemical measurements obtained since 1930 in the Laptev and East Siberian seas.
A. Makshtas, R. Vlasenkov, A. Pavlov
On the basis of original field investigations and archive data stored in the Arctic and Antarctic Research Institute, we plan to study radiation climate, suspended material and dissolved organic matter distributions in the surface layers of the Laptev and East Siberian seas, and the adjacent part of the Central Arctic Basin. We will study the data on the vertical distribution of suspended particles and grain sizes, turbidity, PAR, and spectral irradiance, together with meteorological and oceanographic information, obtained during expeditions to the Laptev (1998, 1999) and East Siberian (2003, 2004) seas and the adjacent part of the Central Arctic Basin (2005). Water samples which will be collected during the expedition of "Academician Fedorov" to the northern Laptev Sea in 2007 will be analyzed with OSL instruments "Sedigraph" and "Specord" to obtain information about the vertical distribution of particulate matter concentration, size distribution and CDOM. The historical Seichi disk and water color data from observations, carried out from the 1950s to the 1980s, will be digitized together with information about cloudiness and weather conditions. The model of solar radiation absorption in the sea surface layer under different cloudy conditions will be utilized together with relationship, obtained by regression analysis, between Sechi depth and the attenuation coefficient for estimation of spatial-temporal variability of radiation heating of the sea surface layer in the study areas.
L. Mazurenko, E. Logvina
Most of the fluid vents located within a gas hydrate stability zone are associated with gas hydrate accumulations. The role of gas hydrate formation in the fluid venting areas is considered of importance both as a potential hydrocarbon source and as a factor influencing the global climate change. Gas hydrate formation in the fluid venting areas could form barriers to free-gas flow, and therefore reduce the amount of gas entering the hydrosphere from the seafloor.Methane hydrate occurrence related to an active fluid vent known from offshore northeast Sakhalin Island is the object of this study. The proposal study continues the OSL-05-17 project "The sources of intensive methane fluxes off NE Sakhalin and the role of gas hydrate formation in the global climate change." The estimation of the period of venting activity based on 14C-dating could give us information on the volume of methane flux in the gas hydrate stability zone of the Sea of Okhotsk. The main goals of the study are to estimate the period and dynamics of fluid venting activities off NE Sakhalin, to reveal their origin and to determine the role gas hydrate formation processes played in Quaternary environmental changes of the Sea of Okhotsk.
Ye. Mironov, T. Alexeeva, A. Timofeeva
The study of the annual cycle and long-term changes of the sea-ice cover is an important scientific and practical problem in the light of global climate change and the necessity to forecast ice conditions for navigation and human activity in the Arctic. The southeastern Barents Sea and southwestern Kara Sea are the best-studied regions in the Arctic. Intensive navigation requires detailed study of the meteorological, oceanographic and especially sea-ice conditions.Special ice observations started in 1986 and since that time sixteen expeditions have been carried out. In these expeditions important morphometrical parameters of the ice cover, such as total concentration, thickness, ice pressure, hummocks and ridges etc., as well as ice thickness measurements by EM sounding were obtained. These records together with satellite SSM/I (since 1987) and AMSR-E (since 2003) images will be used in this study to evaluate the impact of different environmental factors on the quality of ice conditions represented on the satellite images. Further, the field and verified remote sensing data will be analyzed to reveal seasonal and multiannual variabilities of the local sea ice characteristics.
The project is aimed at the multidisciplinary study of modern sedimentary vertical fluxes to the bottom. Previous studies have shown that a viable approach for understanding environmental conditions in the White Sea is to study aquatic palynomorphs assemblages because in marine and bay sediments this group is comprised of both marine and freshwater species. Microecological relations established with hydrographical parameters (e.g. summer surface water salinity, sea-ice conditions) and the composition of surface sediment dinoflagellate assemblages from the White Sea can also be used to reconstruct changes of climate conditions in detail. The main goal of the current proposal is to study the contribution of the dinoflagellate cysts to the modern vertical particle fluxes in the White Sea (European Arctic) as indicator of hydrobiological and sedimentation processes in the arctic seas and to find relationships between the productivity of planktic dinoflagellate algae, the species composition, the seasonal dynamics of theirs cyst production and the regional environmental factors in the White Sea basin. We will focus on the following objectives: •to study aquatic palynomorph remains in the trap samples in order to recognize seasonal dynamics in productivity and species composition of dinoflagellate cyst in te relation to the seasonal environments; •to analyze productivity dynamics of the White Sea phytoplankton using data on hydrobiological observation, satellite viewing and scanning of the upper water layer; •to correlate species composition and abundances of dinoflagellate cysts in sediment traps and surface sediment assemblages from the White Sea, and their relation to the modern hydrological parameters (surface water salinity, sea-ice conditions, and etc.).
V.I. Petrova, P.B. Semenov, A.V. Kursheva
The Arctic Ocean is an indicator sensitively responding to every climatic change. This makes the study of this region indispensable for understanding the formation of the global climate system and its possible changes in the near future. On the basis of complex investigations of organic matter (OM) in the deep-sea sector of the Arctic Ocean, paleogeographic and paleoclimatic conditions can be reconstructed. Within the framework of the project it is proposed to determine the basic organo-geochemical peculiarities of bottom sediments collected in the examined region through the investigation of the molecular structure of different biomarkers and their distribution in the sediments. A synthesis of the data obtained on a wide range of biomarkers including different carbohydrates and derivatives of light-harvesting pigments of primary producers (photoaphtothrofic organisms) will make a more detailed and reliable interpretation possible. The contribution of both terrigenic and marine material to the process of deposition will be estimated. The proposed result of the work is to provide geochemical-stratigraphic schemes reflecting the depositional conditions in the high-latitude zone of the eastern arctic region.
Ye.I. Polyakova, T.S. Klyuvitkina, V.V. Razina
Recent multidisciplinary studies on the Late Pleistocene and Holocene sediments from the Laptev Sea, implemented under the umbrella of the Russian-German "Laptev Sea System" projects, have greatly improved our knowledge about the postglacial environmental history of the region. In the scope of the OSL Fellowship 2002-2005 programs, participants of the current proposal carried out investigations of recent and fossil diatom, aquatic palynomorph, and spore-and-pollen assemblages from the Laptev Sea sediments and the sediment sections of the adjacent islands and hinterland. Our microfossil records and paleoenvironmental reconstructions were presented in several articles and presented at more than 20 international conferences. However, a considerable part of the ample information, obtained by the project team, has not been published yet. Moreover, the PhD students in the team collected representative data on aquatic palynomorph assemblages and spore-and-pollen spectra from the Upper Pleistocene and Holocene sediments in the Laptev Sea region, which they plan to summarize in their PhD theses. This project, therefore, is a continuation of our previous studies of the Late Pleistocene and Holocene Laptev Sea region environments. Our aim is to summarize the microfossil records (diatoms, aquatic palynomorphs, pollen and spores) from the Late Pleistocene and Holocene sediments of the Laptev Sea and the adjacent hinterland and our paleoenvironmental reconstructions in T. Klyuvitkina's and V. Razina's PhD theses, as well as in the book "Postglacial environments in the Laptev Sea deduced from fossil microalgae assemblages" by Ye. Polyakova, T. Klyuvitkina, H. Bauch, and H. Kassens (in Russian) and in several articles.
O. Preobrazhenskaya, A. Moshkina
During our activity at the OSL and the Institute for Polar Ecology, Kiel, we intend to investigate a number of new samples of Arctic pack ice from the White Sea and Arctic Ocean (the samples were obtained with the support of the P.P. Shirshov Institute of Oceanology RAS, Moscow) for biotic (chlorophyll a, sympagic meiofauna) and abiotic parameters. The main goal is to interpret the obtained results for understanding the potential impact of global changes on the arctic ecosystem. The project plan includes several tasks of ice sample analyses and a comparison of these results to previously obtained results. We also plan to compare first-year ice and multi-year ice samples and to receive some information on under-ice waters. The practical result of our work will be an extension of the common database derived from our data and literature.
P. Rekant, V. Tumskoy, P. Khasanov
The proposed project will to combine the analysis of the marine high-resolution seismic data collected during the international Russian-German expedition TRANSDRIFT X in September 2004 and the analysis of the shallow drilling data obtained at modern thermokarst lakes and lagoons of the Bykovskiy Peninsula (grant OSL-05-32). The high lateral and vertical resolution of the data will allow us to create detailed records of the environmental evolution of the last 10 Kyr. Some of the proposed tasks will be addressed for the first time in the Arctic.The main scientific goals of the project include: •reconstruction of the permafrost table distribution and its stability after the Holocene transgression;•reconstruction of the facies succession and environmental evolution for the last 10 Kyr;•correlation of environmental changes within onshore (Ivashkina Lagoon) and offshore key sites (TDR-X polygon, southern Laptev Sea).
V. Shevchenko, A. Filippov, A. Klyuvitkin
We plan to study the role of atmospherically derived elements and compounds, suspended particulate matter, ice-rafted sediments, vertical particle fluxes in the processes taking place in the shelf seas of the western Russian Arctic (the Laptev, Kara, Barents, Pechora and White seas). We will estimate changes in delivery and accumulation of different types of particulate matter and their contribution to major physical and ecological changes in the Northern Eurasian environment. Multidisciplinary approach and 4-dimension studies are necessary including particle flux measurements. Our work will focus on samples from the White Sea because here we have the possibility to realize ideas and principles of the multidisciplinary studies from the Russian-German program "Laptev Sea System" in the White Sea within the framework of the "White Sea System" program. We plan to study the composition of aerosols, suspended particulate matter, sedimentary matter from sediment traps and bottom sediments collected during 18 expeditions to the White Sea. We will compare our results of the White Sea studies with our new analyses and literature data from the other arctic seas, collected by V. Shevchenko and his colleagues since 1991. This project could link ICARP II, SEDIBUD, Arctic Coastal Dynamics and OASIS with the active Russian-German cooperation. It can be a part of the project of Russian-German cooperation within the framework of the Helmholtz Association.
This proposal focuses on the performance of the next stage of research based on the investigations carried out by the grantee during the previous two years (investigation of the ice regime of Russian arctic rivers, collecting datasets) and on some results obtained from previous investigations within the framework of grant OSL-05-06. This project is the final stage of the grantee's master thesis. The main objective is to determine the consequences of changes in the ice regime of Russian Arctic rivers under the influence of global warming. The main scientific problems to be solved during the investigations are the following: •determination of the approximate additional inflow of freshwater to the Arctic Ocean; •estimation of changes of characteristics of the ice phenomena of last decades and ice thickness and a forecast of expected changes in these characteristics; •possible consequences of ice-regime changes for ecology and dynamics of inflow to the Arctic Ocean.The main result of the proposal will be the defense of the grantee's master thesis. The expected results can in addition be used for further research on the hydrology of the arctic rivers and the Arctic Ocean.
E. Taldenkova, A. Stepanova, Ya. Ovsepyan
Detailed paleontological investigations of the AMS14C-dated sediment cores from the Laptev Sea shelf and continental slope carried out within the framework of previous OSL projects revealed an interesting pattern in the downcore distribution of benthic microfossil. This pattern gives evidence for an enhanced water circulation in the Laptev Sea in the Late Holocene, which resulted in a strengthening of the estuarine-like circulation on the shelf and an increasing inflow and upwelling of subsurface Atlantic-derived waters at the western upper continental slope. In order to obtain a detailed record of the Late Holocene climate variability in the Laptev Sea region, it is now planned to perform a high-resolution study of undisturbed boxcore sediment sections by means of benthic microfossil assemblages (ostracods, foraminifers) and conventional proxies (stable isotopes, IRD counts). Six sediment boxcore sections from different parts of the Laptev Sea ranging in depth from the eastern inner shelf (21 m) to the western upper continental slope (270 m) will be continously analyzed for microfossils in 1 to 2-cm thick slices, thus providing a centennial to decadal resolution of the record. To constrain and supplement the microfossil-based climate reconstructions, independent proxies will be used. Stable isotope (d18O and d13C) measurements will be performed on benthic and planktic foraminifers. IRD counts will be carried out in sediment sequences from the deep-water regions of the western Laptev Sea.
B. Vanshtein, E. Bazhenova, M. Dmitrieva
We plan to analyze the origin of tabular ground ice. The basic assumption is that ground ice contains traces of petrogeochemical properties of the rocks in the region of its formation. In case of segregation or intrusion origin, these properties reflect specific features of the underlying rocks, while buried ice from glaciers and glacial ice inherits geochemical properties of atmospheric precipitation in the area of snow accumulation and of rocks underlying flow trajectories. We plan to analyze the samples from a set of ground ice sections in the Kara and Barents seas as well as from arctic ice collections (OSL, AARI, AWI, etc.) from various regions with a number of analytical methods. The results will show whether the primary sources of tabular ground ice are atmospheric precipitation and ground water or marine water.