The ocean could profoundly modulate the ever-increasing atmospheric CO2 by air-sea CO2 exchange process,which is also able to cause significant changes of physical and biogeochemical properties in return.In this study,we assessed the long-term average and spatial-temporal variability of global air-sea CO2 exchange flux(FCO2)since 1980s basing on the results of 18 Coupled Model Intercomparison Project Phase 6(CMIP6)Earth System Models(ESMs).Our findings indicate that the CMIP6 ESMs simulated global CO2 sink in recent three decades ranges from 1.80 to 2.24 Pg C/a,which is coincidence with the results of cotemporaneous observations.What's more,the CMIP6 ESMs consistently show that the global oceanic CO2 sink has gradually intensified since 1980s as well as the observations.This study confirms the simulated FCO2 could reach agreements with the observations in the aspect of primary climatological characteristics,however,the simulation skills of CIMP6 ESMs in diverse open-sea biomes are unevenness.None of the 18 CMIP6 ESMs could reproduce the observed FCO2 increasement in the central-eastern tropical Pacific and the midlatitude Southern Ocean.Deficiencies of some CMIP6 ESMs in reproducing the atmospheric pressure systems of the Southern Hemisphere and the El Nino-Southern Oscillation(ENSO)mode of the tropical Pacific are probably the major causes.

Baoxiao QU;Jinming SONG;Xuegang LI;Huamao YUAN;Kun ZHANG;.Suqing XU

University of Chinese Academy of Sciences,Beijing 100049,China;Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China;Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Marine Ecology and Environmental Sciences Laboratory,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Key Laboratory of Global Change and Marine-Atmospheric Chemistry,Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,China

海洋湖沼学报（英文版）

[1]Baoxiao QU;Jinming SONG;Xuegang LI;Huamao YUAN;Kun ZHANG;.Suqing XU-.Global air-sea CO2 exchange flux since 1980s:results from CMIP6 Earth System Models)[J].海洋湖沼学报（英文版）,2022(04):1417-1436

cotemporaneous,CIMP6,Deficiencies

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