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Title: Significant Biologically Mediated CO 2 Uptake in the Pacific Arctic During the Late Open Water Season
Abstract

Shifting baselines in the Arctic atmosphere‐sea ice‐ocean system have significant potential to alter biogeochemical cycling and ecosystem dynamics. In particular, the impact of increased open water duration on lower trophic level productivity and biological CO2sequestration is poorly understood. Using high‐resolution observations of surface seawater dissolved O2/Ar andpCO2collected in the Pacific Arctic in October 2011 and 2012, we evaluate spatial variability in biological metabolic status (autotrophy vs heterotrophy) as constrained by O2/Ar saturation (∆O2/Ar) as well as the relationship between net biological production and the sea‐air gradient ofpCO2(∆pCO2). We find a robust relationship between∆pCO2and∆O2/Ar(correlation coefficient of −0.74 and −0.61 for 2011 and 2012, respectively), which suggests that biological production in the late open water season is an important determinant of the air‐sea CO2gradient at a timeframe of maximal ocean uptake for CO2in this region. Patchiness in biological production as indicated by∆O2/Arsuggests spatially variable nutrient supply mechanisms supporting late season growth amidst a generally strongly stratified and nutrient‐limited condition.

 
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Award ID(s):
1702371 1733564
NSF-PAR ID:
10460381
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
DOI PREFIX: 10.1029
Date Published:
Journal Name:
Journal of Geophysical Research: Oceans
Volume:
124
Issue:
2
ISSN:
2169-9275
Page Range / eLocation ID:
p. 821-843
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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