Effect of Mesoscale Eddies on Mode Water Formation, Transport and Heat Uptake in the World Ocean
Abstract
The formation, advection and dissipation of subtropical mode water have been proved to impact the world ocean climate through air-sea heat exchange and ventilation processes. While numerical studies suggest that mesoscale eddies influence mode water variability and the associated climate change, this eddy effect has been less analyzed from observations or in a global perspective. Now with the availability of Argo profiling floats to observe ocean interior properties and satellite altimetry to define and track ocean mesoscale eddies (e.g., Chelton et al., 2011; Laxenaire et al., 2018), the colocation between mesoscale eddies and 0-2000 m water masses can be achieved. In this study, first a more precise algorithm is applied to the Argo dataset to define surface mixed layer depths and to detect mode waters. Then, we colocate the selected vertical profiles with mesoscale ocean eddies detected with the TOEddies algorithm (Laxenaire et al., 2018; 2019). It is then possible to capture and quantify the influence of eddies on mode water varieties. Specifically, we revisit the spatial and temporal evolution of mode waters in the five subtropical gyres of the world ocean. The relationship between surface heat flux and the heat stored within mode water layers is also investigated. Nearly all Argo profiles indicate that mode water formation occurs at the time and within the region where loss of latent heat flux from ocean to the atmosphere is significant. In accordance with several studies, anticyclonic eddies, distinctively, play a crucial role in the ventilation of subtropical gyres by advecting mode waters. Our results suggest that such mechanism of ventilation is also key in the uptake of the surplus of heat and carbon generated by human activities.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMOS017..04C
- Keywords:
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- 3339 Ocean/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 4273 Physical and biogeochemical interactions;
- OCEANOGRAPHY: GENERAL;
- 4520 Eddies and mesoscale processes;
- OCEANOGRAPHY: PHYSICAL;
- 4568 Turbulence;
- diffusion;
- and mixing processes;
- OCEANOGRAPHY: PHYSICAL