Premium
Correcting oceanic O 2 /Ar‐net community production estimates for vertical mixing using N 2 O observations
Author(s) -
Cassar Nicolas,
Nevison Cynthia D.,
Manizza Manfredi
Publication year - 2014
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 - 10.1002/2014gl062040
Subject(s) - tracer , mixing (physics) , flux (metallurgy) , vertical mixing , environmental science , atmospheric sciences , mixing ratio , geology , materials science , physics , quantum mechanics , nuclear physics , metallurgy
Abstract The O 2 /Ar approach has become a key method to estimate oceanic net community production (NCP). However, in some seasons and regions of the ocean, strong vertical mixing of O 2 ‐depleted deepwater introduces a large error into O 2 /Ar‐derived NCP estimates. In these cases, undersaturated‐O 2 /Ar observations have for all intents and purposes been ignored. We propose to combine underway O 2 /Ar and N 2 O observations into a composite tracer that is conservative with respect to the influence of vertical mixing on the surface biological O 2 inventory. We test the proposed method with an ocean observing system simulation experiment (OSSE) in which we compare N 2 O‐O 2 /Ar and O 2 /Ar‐only gas flux estimates of NCP to the model‐simulated true NCP in the Southern Ocean. Our proof‐of‐concept simulations show that the N 2 O‐O 2 /Ar tracer significantly improves NCP estimates when/where vertical mixing is important.