日本地球惑星科学連合2023年大会

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[J] オンラインポスター発表

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-AS08] 高性能計算で拓く気象・気候・環境科学

2023年5月22日(月) 13:45 〜 15:15 オンラインポスターZoom会場 (1) (オンラインポスター)

コンビーナ:八代 尚(国立研究開発法人国立環境研究所)、宮川 知己(東京大学 大気海洋研究所)、小玉 知央(国立研究開発法人海洋研究開発機構)、大塚 成徳(国立研究開発法人理化学研究所計算科学研究センター)


現地ポスター発表開催日時 (2023/5/21 17:15-18:45)

13:45 〜 15:15

[AAS08-P08] A Study of Influence of Atmospheric Transport on Interhemispheric Gradient of Carbon Dioxide Based on Observations and Model Simulations

*劉 光宇1八代 尚1丹羽 洋介1 (1.国立環境研究所)

キーワード:二酸化炭素、モデルシミュレーション

The interhemispheric gradient (IHG) of carbon dioxide (CO2) has been used as an important constraint on sources and sinks of carbon. IHG is maintained because anthropogenic CO2 emissions from fossil-fuel consumption are concentrated mainly in the Northern Hemisphere. However, previous studies have reported that the observed IHG variability cannot be reproduced without considering the recent increase in CO2 uptake by vegetation in midlatitudes of the Northern Hemisphere (Ciais et al., 2019). IHG also reflects the variation in interhemispheric CO2 transport. In this study, we used National Centers for Environmental Prediction (NCEP) reanalyses dataset and numerical simulation by Nonhydrostatic Icosahedral Atmospheric Model (NICAM), to make a detailed investigation on the interannual IHG variability focusing on the influence of atmospheric transport on the IHG. Using long-term CO2 observation record of ground stations (compiled by WDCGG), we compared the observed IHG with simulated IHG. Following the previous studies (e.g. Francey and Frederiksen, 2016), we focused on the zonal wind in upper-tropospheric equatorial region (140W-170W, 5N-5S) in boreal winter, called the “duct”. We found that the reproducibility of the duct region was strongly affected by model bias and that interhemispheric transport of CO2 through the duct region was enhanced in the absence of data assimilation (nudging), underestimating the IHG.