THE INFLUENCE OF MESOSCALE FEATURES OF THE SEA-SURFACE TEMPERATURE DISTRIBUTION ON MARINE BOUNDARY-LAYER WINDS OFF THE SCOTIAN SHELF DURINGTHE SUPERSTORM OF MARCH 1993

This paper studies the mesoscale wind field during the blizzard of Mar ch 1993 off the east coast of North America and examines the influence of the sea surface temperature distribution on surface winds. Can the Gulf Stream and its meanders, by its strong influence on the marine b oundary layer, generate mesoscale features in the wind field? Numerica l simulations of the storm are carried out using the MC2. a fully elas tic nonhydrostatic model. Simulations are conducted at different resol utions (50, 25, 10, 5, and 2 km) with both detailed and smoothed SST f ields, so as to examine the influence of these parameters on the marin e boundary layer winds. Results from these numerical simulations are c ompared with surface observations from buoys. The study reveals some m esoscale features in the wind field caused by the Gulf Stream's meande rs and the warm eddies of the SST field. In a stable boundary layer, t he meanders shaped a 50-55-kt (26-28 m s(-1)) band of winds in a gener al 40-45-kt (21-23 m s(-1)) wind field. Behind the cold front, local e nhancements of 10-kt (5 m s(-1)) winds were found over the warm water eddies in the unstable boundary layer.