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I am looking for an explanation for this warm pool of water in the North and North East Bay of Bengal - North Bay Warm Water Anomaly. Currently the path of the sun is towards the southern hemisphere and we are in the fourth week of October. In contrast there are no warm SSTs along the North Arabian Sea.

Is it possible that warm water from the equator has moved up North along the eastern wall of the Bay of Bengal ? Is that indicated by the gyres on display on the Earth Null site ? I observe that there is a warm pool along the eastern seaboard near the equator(negative Indian Ocean Dipole) - IOD Index. Is it possible to show (if my guess is correct) that there is a south to north pressure gradient that is moving warm water north(ageostrophic circulation) ?

Weekly SST Global Anomaly

As you can see the weekly SST global anomaly as well shows a warm pool anomaly in the North Bay of Bengal.

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  • $\begingroup$ You can also check: ospo.noaa.gov/data/sst/anomaly/anomenc.gif $\endgroup$
    – arkaia
    Commented Oct 24, 2016 at 16:30
  • $\begingroup$ @aretxabaleta - more or less confirms the observation. May I have the explanation why ? $\endgroup$
    – user1066
    Commented Oct 24, 2016 at 16:40

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I think the Southeastern Tropical Indian Ocean (SETIO) provides a better hint of what might be happening. It clearly shows a positive pattern since last November. SETIO NOAA source

I think it might be related to the recovery from the intense 2015 El Niño. If I remember from Lau & Nath, 2003, when you have a warm ENSO, you get a reduction of the Monsoon intensity with lower wind speeds, which results in a reduction of sensible and latent heat loss. Also, the cloud cover is reduced because of dryer conditions, which results in a larger percentage of the shortwave radiation reaching the ocean surface.

The WTIO seems pretty normal currently, so it suggest the conditions are mostly eastern Indian Ocean related. The altimetry sea surface height anomaly seems to suggest the currents are counterclockwise in the Bay, so the anomaly seems to be a regional effect.

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    $\begingroup$ SETIO is just in the southeastern Indian ocean. The WTIO gives you an idea of the conditions in the Arabian Sea. Also both of them are just SST. They do not say anything about flow. The WTIO seems pretty normal currently, so it suggest the conditions are mostly eastern Indian Ocean related. For what I can see in the SSH (bulletin.aviso.oceanobs.com/images/…) the currents appear to be counterclockwise in the Bay, so I don't see how they can be pushed up north $\endgroup$
    – arkaia
    Commented Oct 24, 2016 at 18:06

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