JpGU-AGU Joint Meeting 2020

講演情報

[E] ポスター発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS07] 大気化学

コンビーナ:齋藤 尚子(千葉大学環境リモートセンシング研究センター)、中山 智喜(長崎大学 大学院水産・環境科学総合研究科)、豊田 栄(東京工業大学物質理工学院)、内田 里沙(一般財団法人 日本自動車研究所)

[AAS07-P01] Top-down estimation of terrestrial CO2 flux in Northern Eurasia

*白井 知子1石澤 みさ2笹川 基樹1伊藤 昭彦1町田 敏暢1Maksyutov Shamil1 (1.国立環境研究所地球環境研究センター、2.カナダ環境・気候変動省)

キーワード:二酸化炭素、炭素フラックス、逆計算、温室効果気体、シベリア、気候変動

We present a multi-year trend of terrestrial CO2 flux from northern Eurasia, estimated by atmospheric inversion using a coupled model GELCA (Global Eulerian-Lagrangian Coupled Atmospheric model). Global monthly CO2 flux distributions were estimated for the period 2002-2015 for 42 land and 22 ocean regions using the Observation Package data products (ObsPack GLOBALVIEWplus) which includes data from various types of atmospheric CO2 direct measurements provided by large numbers of laboratories in the world. In this study, we added 9 tower observations from JR-STATION (Japan-Russia Siberian Tall Tower Inland Observation Network) to better constrain the area of interest.

In order to examine the impact of additional observational constraints in Siberia, we compared the inversion results with and without JR-STATION data. For the entire period, estimated global land fluxes agreed well with each other regardless of JR-STATION data. At regional scales, estimated fluxes showed significant difference mostly in Siberia and northeastern Europe. When focusing on the mean seasonal variations, summer uptake increased in western Siberia and northeastern Europe whereas it decreased in northeastern Siberia by adding JR-STATION data.

In terms of the long-term trend, the terrestrial sink was increasing both in Siberia and in Europe. Terrestrial CO2 fluxes estimated for Siberia using JR-STATION data is -0.88 ±0.55 GtCyr-1 and -1.36 ±0.42 GtCyr-1 over the period 2002-2009 and 2010-2015, respectively. Those for Europe is -0.19 ±0.43 GtCyr-1 and -0.42 ±0.30 GtCyr-1, respectively. The increasing trend of the carbon sink in northern boreal areas can be explained by the combination of warming climate and the fertilization effect . Time series of these fluxes also reflect the effect of ENSO and extreme weather conditions. The interpretation of the multi-year variation of estimated fluxes in northern Eurasia will be presented.