Permalink : http://hdl.handle.net/2115/45157

ロシア連邦のシベリア地域において航空機とタワーを用いた観測ネットワークを展開して温室効果ガスの長期モニタリングを行った. シベリア地域の二酸化炭素濃度は季節変動の振幅が同じ緯度帯の沿岸域に比べて明らかに大きく, シベリアにおける陸上生態系の活動が盛んであることがうかがえた. シベリアのメタン濃度は同じ緯度帯の沿岸域で観測された濃度より明らかに高い上にその季節変動には冬季と夏季と年に２回の極大値が見られ, 湿地や天然ガス起源のメタン放出が大気中濃度の変動に大きく影響していることが示唆された.
Long-term monitoring for atmospheric greenhouse gases has been conducted by observational network using aircraft and towers in Siberia, Russia. The amplitudes in seasonal variation of carbon dioxide (CO2) observed by towers are 28-33ppb, which are more than 10 ppm larger than those observed at background sites, implying higher biospheric activities in Siberia compared to coastal region. Small vertical difference in annual mean CO2 mixing ratio indicates that emission and absorption fluxes are identical in Siberia. Daytime methane (CH4) mixing ratios exhibit rise in summer and winter at almost all tower sites, which implies that large amount of CH4 is released in summer, especially from wetland. Extremely higher annual mean CH4 in lower altitude compared to upper troposphere suggests that land surface in Siberia acts as a substantial source for CH4.