The Impact of Fluctuating Winds on the Dynamics and Predictability of Anomalous Midlatitude Sea Surface Temperatures

Philip Sura

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A stochastic model of midlatitude sea surface temperature (SST) anomalies that includes the gustiness of sea surface winds is presented. Atmosphere-ocean interactions depend on conditions in the respective boundary layers. In many applications, including the common stochastic view of midlatitude SST anomaly variability as the response to white-noise weather fluctuations, a constant, somehow averaged, or too slowly varying wind speed is used in standard heat flux bulk formulae, and the (effectively stochastic) gustiness of the winds is not taken into account. Nevertheless, observations at Ocean Weather Ship P (and other stations) reveal that stochastic wind fluctuations are crucial to explain the evolution of SST anomalies: The predictions of an extended version of the stochastic SST anomaly model in which the feedback coefficient is not constant but instead includes a stochastic process are in close agreement with observations. Our model (counterintuitively) predicts that atmospheric noise can increase the persistence and predictability of midlatitude SST anomalies and, therefore, has a distinct effect on low-frequency SST variability.

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1 December, 2004
2 PM/ DSRC 1D 403
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