Climatic Influences to Cryosphere-Biosphere in Siberian Permafrost

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In 1994 summer season, two groups (Permafrost and Biology) of the expedition were conducted the field works at eastern Siberia cooperating with Russian researchers from Permafrost Institute and Yakutsk Biological Institute. Peramfrost group aimed to survey the permafrost response to climatic change in both long and short terms. In relation to long term influence of climatic change, ground ice in permafrost, which is locally termed as Edoma, was analyzed as to reconstruct paleo-environmet in the past. Analogus to continental ice sheet, profound information of the paleo-climate were stored into Edoma. On-the-sopt survey of gas concentration of air bubbles in Edoma was done by means of specially desinged portable GC sysytem. Exceptionally high concentration of methane in Edoma was traced indicating the origin of Edoma as Syngenetic Ice-wedge. Organic materials from sediments were collected and were subjected to Radio-carbon dating measurements by AMS system at Nagoya University. Results o … More f dating suggested that Edoma was formed at the time of Karginsky interstadial dated ranges between 30,000yBP and 40,000yBP.In addition to the chemical analysis of Edoma, isotoic caharacters of Oxygen was examined. Temperature changes of the past wrere also traced from the results of isotope concentration profile of Oxygen.Under present trend of global warming, large scale thawing of Edoma occurrs in lowland area of eastern Siberia. The total loss of Edoma was estimaed based on Satellite images and previously measured data. Methane flux from thawing Edoma was caluculated as 10 Mega ton per year. The tundra wetlands developted in summer season is an ideal source of methane because of anaboric environment. The flux of methane from wetland were observed at various locations. The emphirical equation of methane flux was performed with temperatures in summer thaw layr (active layr) and depth of active layr. Adopting this equation to the field conditions, annual flux of methane from wetland was determined as 1 Tera g. Methane gas is one of the major green house effect gases in present atmospher. Based on the estimated fluexes from both thawing Edoma and present wetlands, permafrost is considred as major role of future warming of global climate. Permafrost response to climatic change is not only passive but active manners.Biological group conducted the surveys of vegetation types in tundra and taiga regions. The morphological variability of Pyrola Asarifolia and P.Grandiflora were surveyed. The variability of thiis species were rather larger than prevously reported indicating the influences of climatic change. The spacial distribition of Drosophila was examined at Taiga and Tundra. 11 new species of Drosophila were reported in this field study. All infoamtion was discussed with counterpart reseachers at Yakutsk at the end of march, 1995. Less