HORIZONTALLY INTEGRATED ATMOSPHERIC HEAT-FLUX FROM AN ARCTIC LEAD

Vertical distribution of the horizontally integrated heat injected into the atmosphere by an Arctic lead is investigated, based upon large-eddy simulations of its convective plume. The horizontally integrated heat flux varies exponentially with height except under conditions of relatively weak cross how, when vertical advective transport becomes significant. Its vertical scale, which depends upon the lead size, surface heat flux, atmospheric stratification, and cross-lead wind component, is approximately one fourth of the maximum plume height, indicating that the depth of largest heat transfer is significantly shallower than the depth of the plume. A parameterization is developed to incorporate this small-scale heat injection into large-scale models which cannot resolve individual leads. The amount of heat recaptured by the ice downwind of a lead is significant when cross-lead flow is relatively strong and when the plume depth is shallow.