Impact of Near-Inertial Waves on Vertical Mixing and Air-Sea CO2 Fluxes in the Southern Ocean

Hajoon Song, John Marshall, Jean Michel Campin, Dennis J. McGillicuddy

Research output: Contribution to journalArticle

Abstract

We report the significant impact of near-inertial waves (NIWs) on vertical mixing and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean using a biogeochemical model coupled to an eddy-rich ocean circulation model. The effects of high-frequency processes are quantified by comparing the fully coupled solution (ONLINE) to two offline simulations based on 5-day-averaged output of the ONLINE simulation: one that uses vertical mixing archived from the ONLINE model (CTRL) and another in which vertical mixing is recomputed from the 5-day average hydrodynamic fields (5dAVG). In this latter simulation, processes with temporal variabilities of a few days including NIWs are excluded in the biogeochemical simulation. Suppression of these processes reduces vertical shear and vertical mixing in the upper ocean, leading to decreased supply of carbon-rich water from below, less CO2 outgassing in austral winter, and more uptake in summer. The net change amounts up to one third of the seasonal variability in Southern Ocean CO2 flux. Our results clearly demonstrate the importance of resolving high-frequency processes such as NIWs to better estimate the carbon cycle in numerical model simulations.

Original languageEnglish
Pages (from-to)4605-4617
Number of pages13
JournalJournal of Geophysical Research: Oceans
Volume124
Issue number7
DOIs
Publication statusPublished - 2019 Jan 1

Fingerprint

vertical mixing
oceans
carbon dioxide
Fluxes
air
ocean
Air
simulation
Carbon
Degassing
carbon cycle
Carbon Dioxide
outgassing
hydrodynamics
shears
Numerical models
upper ocean
simulation models
Hydrodynamics
seasonal variation

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Song, Hajoon ; Marshall, John ; Campin, Jean Michel ; McGillicuddy, Dennis J. / Impact of Near-Inertial Waves on Vertical Mixing and Air-Sea CO2 Fluxes in the Southern Ocean. In: Journal of Geophysical Research: Oceans. 2019 ; Vol. 124, No. 7. pp. 4605-4617.
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Impact of Near-Inertial Waves on Vertical Mixing and Air-Sea CO2 Fluxes in the Southern Ocean. / Song, Hajoon; Marshall, John; Campin, Jean Michel; McGillicuddy, Dennis J.

In: Journal of Geophysical Research: Oceans, Vol. 124, No. 7, 01.01.2019, p. 4605-4617.

Research output: Contribution to journalArticle

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