A comparison of observed and geostrophically calculated wintertime surface winds over the East China Sea

Wintertime geostrophic winds ( ), calculated over the East China Sea from surface pressure maps, are compared to observed winds ( ) from the region. For mean winds, the average counterclockwise veering angle from to is 37°, and the average reduction in amplitude is 39%. For fluctuating winds the average veering and attenuation are 25° and 55% The greatest reduction occurs for land stations, while the lowest (33%) occurs at an offshore buoy station. Evidence from power spectral computations suggests that the spectral contents of and are very similar, even for cases where observed winds are of much lower amplitude and do not appear to be reliable.