Global distribution of atmospheric phosphorus sources, concentrations and deposition rates, and anthropogenic impacts

Abstract

A worldwide compilation of atmospheric total phosphorus (TP) and phosphate (PO 4 ) concentration and deposition flux observations are combined with transport model simulations to derive the global distribution of concentrations and deposition fluxes of TP and PO 4 . Our results suggest that mineral aerosols are the dominant source of TP on a global scale (82%), with primary biogenic particles (12%) and combustion sources (5%) important in nondusty regions. Globally averaged anthropogenic inputs are estimated to be ∼5 and 15% for TP and PO 4 , respectively, and may contribute as much as 50% to the deposition over the oligotrophic ocean where productivity may be phosphorus‐limited. There is a net loss of TP from many (but not all) land ecosystems and a net gain of TP by the oceans (560 Gg P a −1 ). More measurements of atmospheric TP and PO 4 will assist in reducing uncertainties in our understanding of the role that atmospheric phosphorus may play in global biogeochemistry.