92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Monday, 23 January 2012: 4:45 PM
Role of Upwelling and Surface Heat Flux in Modulation of Sea Surface Temperature
Room 338 (New Orleans Convention Center )
Xiaodong Hong, NRL, Monterey, CA; and S. Wang, T. Holt, P. J. Martin, and L. W. O'Neill

The sea-surface temperature (SST) changes corresponding to the variability of the atmospheric low-level coastal jet (LLCJ) with respect to strong and weak periods of the jet during the VOCALS field campaign from 20 October to 30 November 2008 are studied using results from a COAMPS two-way fully-coupled air-ocean model simulation. The model results for the variability of the LLCJ and the SST changes are compared with satellite-observed wind and SST.

Two major processes associated with the variability of the LLCJ, Ekman transport and air-sea net heat flux exchange, are investigated. The results indicate that the net heat flux exchange, including the shortwave and longwave radiation and latent and sensible heat flux, is the most prominent process modulating the SST change during both the strong- and weak-jet periods. The maximum SST cooling by the net heat flux is 31% more than by the Ekman transport during the strong-jet period.

The net heat-flux-induced cooling occurs over most of the domain, while the cooling by the Ekman transport occurs within an offshore distance of 500-1000 km. The SST warming during the weak-jet period is also mainly by the net-heat-flux exchange, with a contribution of 71% for the maximum warming. The higher resolution of the two-way-coupled, air-ocean, model simulation provides more detailed insight into the relative roles of the two processes in modulating the SST change.

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