HR: 1340h
AN: B13C-0246    [Abstracts]
TI: Methane Climate Forcing and Methane Release in the Siberian Fresh-Water Systems and Marine Ecosystems.
AU: * Shakhova, N
EM: nshakhov@iarc.uaf.edu
AF: International Arctic Research Center, UAF, 930 Koyukuk Dr., Fairbanks, AK 99775 United States
AU: Semiletov, I
EM: igorsm@iarc.uaf.edu
AF: Pacific Institute of Geography, Russian Academy of Sciences, 5 Radio St., Vladivostok, 690041 Russian Federation
AU: Romanovsky, V
EM: ffver@uaf.edu
AF: International Arctic Research Center, UAF, 930 Koyukuk Dr., Fairbanks, AK 99775 United States
AB: Surface water is a significant part of the Arctic coastal plain landscape, comprising up to 50-80 percent of the land area. In general, Arctic coastal lakes and sea lagoons are thermokarst or thaw by origin. Zones of thawed permafrost called taliks underlie deeper lake and lagoon sediments. Thaw lakes have migrated across the coastal plains during the Holocene (and previous warm epochs), and their concentrations and depth has increased with warmer conditions. Warming increases permafrost thawing and vast organic reservoirs immobilized in permafrost become available for anaerobic destruction through lake growth, migration and developing into sea lagoons. Due to these processes a huge amount of methane releases from fresh-water and shallow marine ecosystems. It might contributes significantly in formation the maximum atmospheric methane over the Arctic exceeds that over Antarctica in wintertime by 8-10 percent. Our direct wintertime methane flux measurements from northern lakes demonstrate that wintertime income of methane provided by them is essential enough to be supposed as underestimated regional wintertime source of methane, because of far less sinks available to balance in winter. As taliks can be through permafrost, another source of atmospheric methane year-round can be associated with disturbance of the sub-sea hydrates. In this report we present the data concerning typical Arctic Siberian lakes, shallow zone of the Laptev and East-Siberian seas.
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4504 Air/sea interactions (0312)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting