OPP-0230455

1. OPP-0230455 Connections Among Atmospheric Forcing, Runoff and Conditions in the Laptev and East –Siberian Seas. I.P.Semiletov and G.E.Weller The First All-hands Meeting of CHAMP PIs and Co-PIs, 18 – 19 February 2003, Boulder, CO.

2. Since the great Siberian rivers play a significant role in the biogeochemical regime of the Arctic Ocean through transport of carbon and nutrients into the sea and through permafrost thawing, we address our project to evaluate the land hydrology effect on the environmental change over most wide Arctic shelf: in the Laptev and East-Siberian seas.

3. Goals of the atmosphere-land-shelf studies are follows: 1) identify what type of atmospheric circulation causes similarities or differences in the precipitation regime of the main East Siberian and their discharge using a complex analysis of types of atmospheric circulation, meteorological and land hydrology records; 2) investigate the connection between the variability in discharge (and their anomalies) in the main East Siberian Rivers and two-circulation regimes of the wind-driven Arctic Ocean as well with dynamics of the Siberian High, and the difference between two patterns of Arctic circulation in hydrology, hydrochemistry and sedimentation (where available) in the Laptev and East-Siberian Seas. 3) determine the linkage between multiyear variability (inter-annual and intra-seasonal) of runoff and marine environment (hydrology and hydrochemistry) and ice condition (where available)

4. Knowledge of the coastal processes as a linkage between land and ocean processes in the Arctic is a primary interest of this project because the major transport of fresh water, dissolved and solid material into the Arctic Ocean is determined by 1) the fluvial discharges and 2) coastal erosion. Major transport of terrestrial solid material into the Arctic Ocean: the Laptev and East-Siberian seas. Modified from Semiletov, submitted to GRL

5. Custody of I.Semiletov We determine the inter-annual and intra-seasonal variability of atmospheric forcing over East Siberia and the adjacent part of the Arctic Ocean that influences the land hydrology, runoff, water circulation and biogeochemical regime on the East Siberian Shelf. How we do this: by acquiring, synthesing, integrating and comparing land-shelf (meteorology, land and marine hydrology, hydrochemistry and sediment data for two seminal areas of the Arctic: 1) the Lena- Laptev Sea system, and 2) the East-Siberian land-shelf system, which is influenced strongly by the Pacific water inflow.

6. Data sets. All available meteorological, hydrological, and hydrochemical data sets obtained by the Russian Academy of Sciences, Hydromet , Navy Hydrography, and other institutions, and including results of our own investigations (three cruises along the Lena River from Yakutsk to Tiksi, 1995, 1998, 1999; all-seasonal observations in the Lena Delta, 1994-1996 and seven summer-fall oceanographic expeditions including Trans-Arctic Expedition-2000). Data are taken from the published (USA web sites), digitized and solid Cadastre and Bulletin yearbooks of Yakutian Hydromet (Yakutsk, Tiksi, Cherskiy) and Roskomhydromet (Moscow, Obninsk), Russian Academy of Sciences (Vladivostok, Moscow), Far Eastern Hydromet, Navy Hydrography as well from the unpublished reports of Tiksi Hydromet. Custody of I.Semiletov

7. Mean summer distribution of T,S (1932-2000) in the surface and bottom waters of the Laptev (1,936 st.) and East-Siberian Seas (3,594 st.) . Custody of V.Luchin and I.Semiletov

8. DISTRIBUTION OF ORGANIC CARBON AND NITROGEN AND THEIR STABLE ISOTOPES IN THE EAST-SIBERIAN SEA (Custody of Semiletov, Dudarev, Shin, and Tanaka) shows strong influence of marine (Pacific) processes on sedimentation in the eastern part of the East-Siberian sea bounded at near 170E (similar with mean multi-year TS frontal position )

9. We are looking for opportunities for collaborative cross-cutting research among CHAMP/ASOF/SEARCH projects