Year: 2025
Type: article
Abstract: Understanding the dynamics of terrestrial carbon sources and sinks is crucial for addressing climate change, yet significant uncertainties remain at regional scales. We developed the Monitoring and Evaluation of Greenhouse gAs Flux (MEGA) inversion system with satellite data assimilation and applied it to China using OCO-2 V11.1r XCO2 retrievals. Our results show that China’s terrestrial ecosystems acted as a carbon sink of 0.28 ± 0.15 PgC yr−1 during 2018–2023, consistent with other inversion estimates. Validation against surface CO2 flask measurements demonstrated significant improvement, with RMSE and MAE reduced by 30%–46% and 24–44%, respectively. Six sets of prior sensitivity experiments conclusively demonstrated the robustness of MEGA. In addition, this study is the first to systematically compare model-derived and observation-based background fields in satellite data assimilation. Ten sets of background sensitivity experiments revealed that model-based background fields exhibit superior capability in resolving seasonal flux dynamics, though their performance remains contingent on three key factors: (1) initial fields, (2) flux fields, and (3) flux masks (used to control regional flux switches). These findings highlight the potential for further refinement of the atmospheric inversion system.
Source: Remote Sensing
DOI: 10.3390/rs17223720
Institutions: Zhejiang University, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing University, Zhejiang University of Technology, University of Hong Kong, Nanjing University of Information Science and Technology, Massachusetts Institute of Technology
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $3,258
Awards: G1247606099, 人为减排及气候变化对浙江省空气质量影响研究
OpenAlex ID: W4416225211