Wednesday, 17 January 2007: 4:30 PM
Effects of a diurnal sea surface temperature on surface fluxes and atmospheric variability
214C (Henry B. Gonzalez Convention Center)
A coupled atmosphere-ocean single-column model is used to evaluate the effects of diurnal sea surface temperature variability on the marine boundary layer. It has been shown that the use of a diurnally-varying sea surface temperature as opposed to a daily-averaged sea surface temperature can substantially impact the lower atmosphere by several degrees, and the upper atmosphere through convection. The extent to which a daily-averaged sea surface temperature changes the resulting atmospheric profiles depends on whether the diurnal variability was strong; under low-wind conditions the differences are the most dramatic. Such perturbations as the Madden-Julian Oscillation with active and suppressed phases in the tropical western Pacific can affect the magnitude of the diurnal warming. The two boundary layers are coupled through the air-sea fluxes of heat and moisture in these model simulations, but the mechanisms causing the extensive and long-lasting atmospheric variability have not yet been identified. These mechanisms and an analysis of the feedbacks at various scales and differing sea surface temperature diurnal warming regimes are shown.
Supplementary URL: