Distinct influence of air–sea interactions mediated by mesoscale sea surface temperature and surface current in the Arabian Sea
MetadataShow full item record
During the southwest monsoons, the Arabian Sea (AS) develops highly energetic mesoscale variability associated with the Somali Current (SC), Great Whirl (GW), and cold filaments (CF). The resultant high-amplitude anomalies and gradients of sea surface temperature (SST) and surface currents modify the wind stress, triggering the so-called mesoscale coupled feedbacks. This study uses a high-resolution regional coupled model with a novel coupling procedure that separates spatial scales of the air–sea coupling to show that SST and surface currents are coupled to the atmosphere at distinct spatial scales, exerting distinct dynamic influences. The effect of mesoscale SST–wind interaction is manifested most strongly in wind work and Ekman pumping over the GW, primarily affecting the position of GW and the separation latitude of the SC. If this effect is suppressed, enhanced wind work and a weakened Ekman pumping dipole cause the GW to extend northeastward, delaying the SC separation by 1°. Current–wind interaction, in contrast, is related to the amount of wind energy input. When it is suppressed, especially as a result of background-scale currents, depth-integrated kinetic energy, both the mean and eddy, is significantly enhanced. Ekman pumping velocity over the GW is overly negative because of a lack of vorticity that offsets the wind stress curl, further invigorating the GW. Moreover, significant changes in time-mean SST and evaporation are generated in response to the current–wind interaction, accompanied by a noticeable southward shift in the Findlater Jet. The significant increase in moisture transport in the central AS implies that air–sea interaction mediated by the surface current is a potentially important process for simulation and prediction of the monsoon rainfall.
Author Posting. © American Meteorological Society, 2017. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 30 (2017): 8061-8080, doi:10.1175/JCLI-D-16-0834.1.
Suggested CitationJournal of Climate 30 (2017): 8061-8080
Showing items related by title, author, creator and subject.
Atlantis II : cruise 102 : moored and shipboard surface meteorological measurements during JASIN 1978 Briscoe, Melbourne G.; Alessi, Carol A.; Payne, Richard E.; Peal, Kenneth R. (Woods Hole Oceanographic Institution, 1979-12)During cruise 102 of the R/V Atlantis-II in the Joint Air-Sea Interaction Project (JASIN), surface meteorological data were gathered by Woods Hole Oceanographic Institution personnel from two moored buoys and from the ...
Moored observations of the surface meteorology and air-sea fluxes in the Northern Bay of Bengal in 2015 Weller, Robert A.; Farrar, J. Thomas; Seo, Hyodae; Prend, Channing; Sengupta, Debasis; Lekha, J. Sree; Ravichandran, M.; Venkatesan, Ramasamy (American Meteorological Society, 2018-12-28)Time series of surface meteorology and air–sea fluxes from the northern Bay of Bengal are analyzed, quantifying annual and seasonal means, variability, and the potential for surface fluxes to contribute significantly to ...
Seo, Hyodae; Subramanian, Aneesh C.; Miller, Arthur J.; Cavanaugh, Nicholas R. (American Meteorological Society, 2014-11-15)This study quantifies, from a systematic set of regional ocean–atmosphere coupled model simulations employing various coupling intervals, the effect of subdaily sea surface temperature (SST) variability on the onset and ...