Anthropogenic aerosol depositions of nitrogen and phosphorus reduces the sensitivity of oceanic productivity to warming
Abstract Satellite data reveal a strong link between contemporary oceanic productivity and climate. Models suggest oceanic productivity is reduced in response to enhanced water stratification induced by warming, but do not include the effect of increasing anthropogenic aerosol depositions of nitrogen and phosphorus (AAD) We model the response of oceanic productivity and chlorophyll to AAD, supported by in situ nutrient and chlorophyll measurements. As a result, AAD reduces the sensitivity of oceanic productivity to sea surface temperature from 15.2+ 1.8 to 13.3+ 1.6 Pg C ydegC in the stratified ocean during 1948 2007. The reduction over the North Atlantic, North Pacific and Indian oceans reaches 40, 24 and 25% respectively. We hypothesize that future reduction of aerosol emissions in response to higher air quality standards will accelerate the decline of oceanic productivity per unit warming.