Update on the Temperature Corrections of Global Air-Sea CO2 Flux Estimates

Type Article
Date 2022-09
Language English
Author(s) Dong Yuanxu1, 2, Bakker Dorothee C. E.1, Bell Thomas G.2, Huang Boyin3, Landschutzer Peter4, Liss Peter S.1, Yang Mingxi2
Affiliation(s) 1 : Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, UK
2 : Plymouth Marine Laboratory, Prospect Place, Plymouth, UK
3 : National Centers for Environmental Information, National Oceanic and Atmospheric Administration, Ashddeeville, NC, USA
4 : Max Planck Institute for Meteorology, Hamburg, Germany
Source Global Biogeochemical Cycles (0886-6236) (Amer Geophysical Union), 2022-09 , Vol. 36 , N. 9 , P. e2022GB007360 (13p.)
DOI 10.1029/2022GB007360
WOS© Times Cited 7
Keyword(s) air-sea CO2 flux, temperature effects, updated correction
Abstract

The oceans are a major carbon sink. Sea surface temperature (SST) is a crucial variable in the calculation of the air-sea carbon dioxide (CO2) flux from surface observations. Any bias in the SST or any upper ocean vertical temperature gradient (e.g., the cool skin effect) potentially generates a bias in the CO2 flux estimates. A recent study suggested a substantial increase (similar to 50% or similar to 0.9 Pg C yr(-1)) in the global ocean CO2 uptake due to this temperature effect. Here, we use a gold standard buoy SST data set as the reference to assess the accuracy of insitu SST used for flux calculation. A physical model is then used to estimate the cool skin effect, which varies with latitude. The bias-corrected SST (assessed by buoy SST) coupled with the physics-based cool skin correction increases the average ocean CO2 uptake by similar to 35% (0.6 Pg C yr(-1)) from 1982 to 2020, which is substantially smaller than the previous correction. After these temperature considerations, we estimate an average net ocean CO2 uptake of 2.2 +/- 0.4 Pg C yr(-1) from 1994 to 2007 based on an ensemble of surface observation-based flux estimates, in line with the independent interior ocean carbon storage estimate corrected for the river induced natural outgassing flux (2.1 +/- 0.4 Pg C yr(-1)).

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How to cite 

Dong Yuanxu, Bakker Dorothee C. E., Bell Thomas G., Huang Boyin, Landschutzer Peter, Liss Peter S., Yang Mingxi (2022). Update on the Temperature Corrections of Global Air-Sea CO2 Flux Estimates. Global Biogeochemical Cycles, 36(9), e2022GB007360 (13p.). Publisher's official version : https://doi.org/10.1029/2022GB007360 , Open Access version : https://archimer.ifremer.fr/doc/00795/90657/