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Seasonal evolution of the surface layer heat balance in the eastern subtropical Indian Ocean

Citation

Cyriac, A and McPhaden, MJ and Phillips, HE and Bindoff, NL and Feng, M, Seasonal evolution of the surface layer heat balance in the eastern subtropical Indian Ocean, Journal of Geophysical Research: Oceans, 124, (9) pp. 6459-6477. ISSN 2169-9275 (2019) [Refereed Article]


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Copyright Statement

Copyright 2019 American Geophysical Union. Further reproduction or electronic distribution is not permitted.

DOI: doi:10.1029/2018JC014559

Abstract

The south Indian Ocean (SIO) is a region of strong air‐sea heat loss due to the unique ocean circulation pattern influenced by the Indonesian Throughflow. In this study, the seasonal variation of the surface layer heat budget in the eastern SIO is investigated using 2 years of measurements from a mooring at 25S, 100E, the only colocated upper ocean and surface meteorology time series in the subtropical Indian Ocean. The mooring data are combined with other in situ and satellite data to examine the role of air‐sea fluxes and ocean heat transport on the evolution of mixed layer temperature using heat budget diagnostic models. Results show that on seasonal timescales, mixed layer heat storage in the eastern SIO is mostly balanced by a combination of surface fluxes and turbulent entrainment with a contribution from horizontal advection at times. Solar radiation dominates the seasonal cycle of net surface heat flux, which warms the mixed layer during austral summer (67 Wm‐2) and cools it during austral winter (‐44 Wm‐2). Entrainment is in good agreement with the heat budget residual for most of the year. Horizontal advection is spatially variable and appears to be dominated by the presence of mesoscale eddies and possibly annual and semi‐annual Rossby waves propagating from the eastern boundary. Results from the 2‐year mooring‐based data analysis are in reasonably good agreement with a 12‐year regional heat budget analysis around the mooring location using ocean reanalysis products.

Item Details

Item Type:Refereed Article
Keywords:Indian Ocean, air-sea interaction, moored observations
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical Oceanography
Objective Division:Environment
Objective Group:Climate and Climate Change
Objective Field:Climate Variability (excl. Social Impacts)
UTAS Author:Cyriac, A (Ms Ajitha Cyriac)
UTAS Author:Phillips, HE (Associate Professor Helen Phillips)
UTAS Author:Bindoff, NL (Professor Nathan Bindoff)
ID Code:134365
Year Published:2019
Deposited By:Oceans and Cryosphere
Deposited On:2019-08-09
Last Modified:2019-11-05
Downloads:20 View Download Statistics

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