13:45 〜 15:15
[MIS01-P03] Spatio-temporal variations of atmospheric CO2 and CH4 over the continent-sea interface in the Yenisei River sector of the Kara Sea
キーワード：Arctic, Climate, Atmospheric composition, Carbon dioxide, Methane
Observations of the atmospheric sources and sinks of carbon dioxide (CO2) and methane (CH4) in the pan-Arctic domain are extremely scarce, restricting our knowledge of carbon turnover over this climatically sensitive environment and the fate of carbon reservoirs conserved in the permafrost. Especially critical are the gaps in the high latitudes of Siberia, covered by the vast permafrost underlain tundra, where only a few sites measure variations of CO2 and CH4 in the atmosphere to analyze their emissions and trends.
We present the first years of accurate continuous observations of atmospheric CO2 and CH4 dry mole fractions at the recently deployed tower-based measurement station “DIAMIS” (73.5068 N, 80.5198 E) located on the southwestern coast of the Taimyr Peninsula, Siberia, at the Gulf of the Yenisei River that opens to the Kara Sea (Arctic Ocean). We summarize the scientific rationale of the site, examine the seasonal footprint, and illustrate temporal patterns of CO2 and CH4 for the daytime mixed atmospheric layer over the continent–sea interface. Along with the temporal variations reflecting a signal caused pan-Arctic and not very much influenced by the local processes, we analyze the spatio-temporal distribution of the synoptic anomalies representing the atmospheric signatures of regional sources and sinks of CO2 and CH4 for the studied high-arctic Siberian domain of ~625 thousand km2, with nearly equal capturing the land surface (54%) and the ocean (46%) throughout the year. Both for CO2 and CH4, we have observed a sea – continent declining trend, presuming a larger depletion of trace gases in the maritime air masses compared to the continental domain. So far, we have not detected any prominent signals of CH4 over the Kara Sea that might have indicated processes of subsea permafrost degradation and occurrence of cold seeps – still mainly observed in the eastern Arctic Seas.
The reported study was funded by the Russian Science Foundation (RSF), project # 23-17-20007. IS acknowledges the Ministry of Science and High Education (grant ID: 075-15-2020-928). MK acknowledges the RSF project # 21-17-00163.
We present the first years of accurate continuous observations of atmospheric CO2 and CH4 dry mole fractions at the recently deployed tower-based measurement station “DIAMIS” (73.5068 N, 80.5198 E) located on the southwestern coast of the Taimyr Peninsula, Siberia, at the Gulf of the Yenisei River that opens to the Kara Sea (Arctic Ocean). We summarize the scientific rationale of the site, examine the seasonal footprint, and illustrate temporal patterns of CO2 and CH4 for the daytime mixed atmospheric layer over the continent–sea interface. Along with the temporal variations reflecting a signal caused pan-Arctic and not very much influenced by the local processes, we analyze the spatio-temporal distribution of the synoptic anomalies representing the atmospheric signatures of regional sources and sinks of CO2 and CH4 for the studied high-arctic Siberian domain of ~625 thousand km2, with nearly equal capturing the land surface (54%) and the ocean (46%) throughout the year. Both for CO2 and CH4, we have observed a sea – continent declining trend, presuming a larger depletion of trace gases in the maritime air masses compared to the continental domain. So far, we have not detected any prominent signals of CH4 over the Kara Sea that might have indicated processes of subsea permafrost degradation and occurrence of cold seeps – still mainly observed in the eastern Arctic Seas.
The reported study was funded by the Russian Science Foundation (RSF), project # 23-17-20007. IS acknowledges the Ministry of Science and High Education (grant ID: 075-15-2020-928). MK acknowledges the RSF project # 21-17-00163.