Estimates of particulate organic carbon over the euphotic depth from in situ measurements. Application to satellite data over the global ocean
Résumé
Knowledgeoftheoceanicparticulateorganiccarbon(POC)poolandofitsspatio-temporalvariabilityis importantforunderstandingtheoceaniccarboncycle.Untilnow,POCestimatesfromspacehavebeen restrictedtothesurfacelayer.AnempiricalalgorithmisdevelopedtoderivethePOCcontentintegrated overtheeuphoticlayer(POCZeu) fromthenear-surfacePOCconcentration(POCsurf ).Therelationshipfollows a power-lawdistribution,POCZeu ¼ APOCB surf, with A and B depending onthetypeofwaters(stratifiedor well-mixed)andonthenear-surfacechlorophyllconcentration.AglobalclimatologyofPOCsurf andPOCZeu is generatedfromtheSeaWiFSarchivebetween1998and2006.TheglobalpatternsofPOCsurf and POCZeu follow themajorgyresystemsandotherlarge-scalecirculationfeatures.HighsurfaceandintegratedPOC content, around150mgm 3 and 6000mgm 2, areencounteredathighlatitude,whereaslowcontent, o50mgm 3 and 2000mgm 2, areobservedinsubtropicalgyres.ThemeanglobalvaluesofPOCsurf and POCZeu overtheglobaloceanare53mgm 3 and 3742mgm 2. ThestandingstocksofPOCare3:92 1014 and 1:19 1015 g overthefirstpenetrationandeuphoticdepth,respectively