Premium
Limited impact of atmospheric nitrogen deposition on marine productivity due to biogeochemical feedbacks in a global ocean model
Author(s) -
Somes Christopher J.,
Landolfi Angela,
Koeve Wolfgang,
Oschlies Andreas
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl068335
Subject(s) - biogeochemistry , biogeochemical cycle , denitrification , environmental science , nitrogen , deposition (geology) , nitrogen cycle , productivity , nitrogen fixation , reactive nitrogen , carbon cycle , oceanography , environmental chemistry , atmospheric sciences , ecosystem , ecology , chemistry , geology , biology , paleontology , organic chemistry , sediment , economics , macroeconomics
The impact of increasing anthropogenic atmospheric nitrogen deposition on marine biogeochemistry is uncertain. We performed simulations to quantify its effect on nitrogen cycling and marine productivity in a global 3‐D ocean biogeochemistry model. Nitrogen fixation provides an efficient feedback by decreasing immediately to deposition, whereas water column denitrification increases more gradually in the slowly expanding oxygen deficient zones. Counterintuitively, nitrogen deposition near oxygen deficient zones causes a net loss of marine nitrogen due to the stoichiometry of denitrification. In our idealized atmospheric deposition simulations that only account for nitrogen cycle perturbations, these combined stabilizing feedbacks largely compensate deposition and suppress the increase in global marine productivity to <2%, in contrast to a simulation that neglects nitrogen cycle feedbacks that predicts an increase of >15%. Our study emphasizes including the dynamic response of nitrogen fixation and denitrification to atmospheric nitrogen deposition to predict future changes of the marine nitrogen cycle and productivity.