Seasonal variation in eddy activity and associated heat/salt transport in the Bay of Bengal based on satellite, Argo, and 3D reprocessed data
<p>Based on satellite altimetry data spanning over 26 years in combination with Argo profile data or three-dimensional (3D) reprocessed thermohaline fields, the eddy synthesis method was used to construct vertical temperature and salinity structures of eddies in the Bay of Bengal, and the seas...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-11-01
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| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/18/1645/2022/os-18-1645-2022.pdf |
| Summary: | <p>Based on satellite altimetry data spanning over 26 years
in combination with Argo profile data or three-dimensional (3D) reprocessed
thermohaline fields, the eddy synthesis method was used to construct
vertical temperature and salinity structures of eddies in the Bay of Bengal,
and the seasonal thermohaline properties of eddies and the heat and salt
transport by eddies were analyzed. Analysis revealed that mesoscale eddy
activities and the vertical thermohaline structures in the Bay of Bengal
have evident seasonal variation. Temperature anomalies caused by eddies are
usually between <span class="inline-formula">±1</span> and <span class="inline-formula">±3</span> <span class="inline-formula"><sup>∘</sup></span>C (positive
for anticyclonic eddies (AEs) and negative for cyclonic eddies (CEs)), and
the magnitude varies seasonally. Salinity anomalies caused by eddies are
small and disturbance signals in the southern bay due to the small vertical
gradient of salinity there; salinity anomalies in the northern bay are
generally between <span class="inline-formula">±0.2</span> and <span class="inline-formula">±0.3</span> psu, negative for AEs and
positive for CEs. Owing to seasonal changes in both the eddy activity and
the vertical thermohaline structure in the Bay of Bengal, the eddy-induced
heat and salt transport in different seasons also changes substantially.
Generally, high heat and salt transport is concentrated in eddy-rich
regions, e.g., the western, northwestern, and eastern parts of the bay, the
seas to the east of Sri Lanka, and the region to the southeast outside of
the bay. The southern part of the bay shows weak salt transport owing to the
inconsistent salinity signal within eddies. The result of the divergence of
eddy heat transport illustrates that the 10–20 W m<span class="inline-formula"><sup>−2</sup></span> value
of the eddy-induced heat flux is comparable in magnitude with the annual
mean air–sea net heat flux in the Bay of Bengal. Compared with the
large-scale net heat flux and freshwater flux at the surface, the eddy-induced
heat/freshwater transport can contribute substantially to regional and
basin-scale heat/freshwater variability. This work provides data that could
support further research on the heat and salt balance of the entire Bay of
Bengal.</p> |
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| ISSN: | 1812-0784 1812-0792 |