On the influence of “non‐Redfield” dissolved organic nutrient dynamics on the spatial distribution of N2 fixation and the size of the marine fixed nitrogen inventory

摘要: Dissolved organic nitrogen (DON) and phosphorus (DOP) represent the most abundant form of their respective nutrient pool in surface layer oligotrophic oceans play an important role cycling productivity. Since DOP is generally more labile than DON, it provides additional P that may stimulate growth nitrogen-fixing diazotrophs supply fixed to balance denitrification ocean. In this study, we introduce semirecalcitrant components DON as state variables existing global ocean-atmosphere-sea ice-biogeochemistry model intermediate complexity assess impact on spatial distribution fixation size marine inventory. Large-scale data sets Atlantic Ocean are used constrain model. Our simulations suggest both preferential remineralization phytoplankton uptake "non-Redfield" processes (i.e., deviate from molar N:P=16) need be accounted for explain observed patterns DOP. Additional non-Redfield sensitivity experiments testing dissolved matter (DOM) production rate uncertainties best reproduce increases inventory by 4.7±1.7% compared simulation assuming Redfield DOM stoichiometry underestimates The extra 8Tgyr-1 stimulated mainly responsible increase due its large separation water column denitrification, which buffers any potential surplus Pacific Ocean. study suggests budget sensitive dynamics because access relatively expands ecological niche diazotrophs.