Winter Offshore/Onshore Wind Differences in Southeastern Hudson Bay, Canada

Résumé

Acquisition of two 38-day wind data sets collected over a fast-ice shelf and at a nearby coastal weather station (Kuujjuarapik) in Hudson Bay allowed the calculation for the first time of an offshore/onshore wind speed ratio for an ice-covered environment. Mean wind over the ice was 29% higher than at the coast, compared to values of 65% for open ocean locations. This reflects the effect of the higher drag coefficient of the sea ice that more strongly attenuates the wind than does the sea surface. The data set also allowed the evaluation of the change in the wind field by local topography. Thus, a strong orographic effect was found in the SW quadrant, as winds of less than 5 m/s were deflected toward the SE and NW.