Space and time variability of the Southern Ocean carbon budget

TitleSpace and time variability of the Southern Ocean carbon budget
Publication TypeJournal Article
Year of Publication2017
AuthorsRosso I., Mazloff MR, Verdy A., Talley LD
JournalJournal of Geophysical Research-Oceans
Volume122
Pagination7407-7432
Date Published2017/09
Type of ArticleArticle
ISBN Number2169-9275
Accession NumberWOS:000413167200025
Keywordscarbon budget; co2 atlas; dioxide; global overturning circulation; kerguelen plateau; natural iron fertilization; phytoplankton bloom; ross; sea; sea-ice; socat; Southern Ocean; state estimate; trends; version 2
Abstract

The upper ocean dissolved inorganic carbon (DIC) concentration is regulated by advective and diffusive transport divergence, biological processes, freshwater, and air-sea CO2 fluxes. The relative importance of these mechanisms in the Southern Ocean is uncertain, as year-round observations in this area have been limited. We use a novel physical-biogeochemical state estimate of the Southern Ocean to construct a closed DIC budget of the top 650 m and investigate the spatial and temporal variability of the different components of the carbon system. The dominant mechanisms of variability in upper ocean DIC depend on location and time and space scales considered. Advective transport is the most influential mechanism and governs the local DIC budget across the 10 day-5 year timescales analyzed. Diffusive effects are nearly negligible. The large-scale transport structure is primarily set by upwelling and downwelling, though both the lateral ageostrophic and geostrophic transports are significant. In the Antarctic Circumpolar Current, the carbon budget components are also influenced by the presence of topography and biological hot spots. In the subtropics, evaporation and air-sea CO2 flux primarily balances the sink due to biological production and advective transport. Finally, in the subpolar region sea ice processes, which change the seawater volume and thus the DIC concentration, compensate the large impact of the advective transport and modulate the timing of biological activity and air-sea CO2 flux.

DOI10.1002/2016jc012646
Short TitleJ Geophys Res-Oceans
Student Publication: 
No