The effect of stochastic surface heat fluxes on the climatology of the seasonal thermocline

Abstract

The stochastic forcing theory of Frankignoul and Hasselmann, 1977 is modified to include a mixed layer model. This enables the examination of the interaction between stochastic heat flux or wind stress components and the annual period surface heat flux. The presence of the stochastic heat flux component causes the average sea surface temperature to be 0.75 C higher than it would be with only the annual period component. it also delays the time of maximum surface temperature, and it causes the average mixed layer depth to be ten meters shallower. A stochastic wind stress component applied to an annual heat flux cycle produces a smaller sea surface temperature variance, but it results in a more rapidly deepening and deeper mixed layer than achieved with an annual cycle and constant wind stress. The stochastic forcing wind model shows that the climatology of the seasonal thermocline is dependent on nonlinear interactions between the annual cycle and stochastic forcing.