Annually variation of air-sea carbon flux in the southern ocean from three CHINARE cruises by means of remote sensing technology

Empirical relationships were derived from the underway measurements of sea surface pCO2, chlorophyll-a and sea surface temperature obtained from three Chinese Antarctica Research Expedition (CHINARE) cruises conducted in south Atlantic Ocean and south Indian Ocean. pCO2 in sea water was computed from remote sensing chlorophyll-a and SST by extrapolation method. Monthly spatiotemporal distribution of air-sea CO2 flux was calculated. Results showed that in general the carbon absorption was stronger in January than in December, and declined in February. The carbon absorption in Dec 1999 and 2004 was approximately equal, while in Dec 2007 it declined by 9% compared to Dec 1999. For January, the carbon absorption in 2005 declined by 8.4% compared to 2000. While for February 2008, due to the reforming of sea ice and decrease of chlorophyll, the carbon absorption decreased.