Simple equations to estimate ratios of new or export production to total production from satellite-derived estimates of sea surface temperature and primary production

Edward A. Laws, Eurico D'Sa, Puneeta Naik

Limnol. Oceanogr. Methods 9:593-601 (2011) | DOI: 10.4319/lom.2011.9.593

ABSTRACT: Two simple equations with sea surface temperature and total primary production as independent variables were used to estimate ratios of new or export production to total primary production (ef-ratios) in the ocean. Both equations assume that ef-ratios are negatively correlated with temperature in a linear manner and positively correlated with total primary production in a curvilinear manner characteristic of a Holling type II function. The two equations were parameterized based on different sets of field data: in one case entirely from estimates of new production based on nitrate uptake, and in the other case based on a comprehensive summary of new and export production estimates derived from a combination of techniques. Estimates of global export production based on satellite observations and use of the two equations were 9-13 Gt C per year. The form of both equations likely captures the principal effects of temperature and total production on ef-ratios, and their mathematical simplicity should facilitate their prognostic application in climate change research and studies of the ocean's carbon cycle.