DECADAL EVOLUTION OF CARBON SINK WITHIN A STRONG BLOOM AREA IN THE SUBANTARCTIC ZONE

摘要

Seasonal to decadal changes of surface fCO_2 are assessedrnalong the track between Kerguelen and Amsterdamrnislands. Data from 17 oceanographic cruises are used,rnfrom 1991 to 2011 and two distinct regions are examined,rnseparated by the Subantarctic Front (SAF). The regionrnsouth of the SAF displays a strong summerrnphytoplankton bloom of up to -28 mmol C m~(-2)d~(-1) within arncalm area, constrained by physics and topography. Thisrnregion is a 6-fold more important annual sink than thatrndeduced from Takahashi climatology, highlighting thernimportance of key-areas separate examination beforernproceeding to spatial integration. Our data reveal arndecadal decline of the summer CO_2 sink in the Southernrnpart of the SAF, due to both warming and less Fe input tornsurface waters from reduced water mixing.