TESTING DRAG COEFFICIENT APPROACHES BY USING THE BUOY DATA COLLECTED IN MODERATE TO HIGH WIND UNDER FOLLOWING,CROSSING AND OPPOSING SWELL CONDITIONS

作者：彭文武,高志球,李煜斌,张荣智,童兵,吴彬贵,何宜军

摘要：Hurricane intensity and track are strongly affected by air-sea interactions. Classified as following swells,crossing swells, and opposing swells, the observed wave height was parameterized by using the 10-m wind speed collected on 5 buoys by the National Buoy Data Center during 13 hurricane events. The path information of these 13 hurricanes was obtained from the National Hurricane Center Best Track(NHC-BT). Results show that the wave height increases exponentially with the 10-m wind speed, and the wave height reaches the maximum value, 11.2 m(8.1 m),when 10-m wind speed is 40 m s-1 under the following and crossing(opposing) swell conditions. We find that the wave steepness(the ratio of wave height to wave length) is proportional to the-2/3 power of the wave age(the ratio of wave phase velocity to 10-m wind speed). The parameterizations of friction velocity and drag coefficient are tested using the buoy data collected in moderate to high wind under following, crossing and opposing swell conditions. A wave age dependent equation for drag coefficient is found more accurate and recommended for future usage in numerical models.Furthermore, these algorithms also suggest that wind-swell orientation needs to be considered to retrieve accurate surface drag under high winds and strong swells.

发文机构：Jiangsu Key Laboratory of Agriculture Meteorology School of Atmospheric Physics Meteorological Center of East China Regional Air Traffic Management Bureau of Civil Aviation of China Tianjin Institute of Meteorological Science Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters

关键词：dragcoefficientHIGHWINDWAVEheightWAVEageSWELL

分类号： P457.8[天文地球—大气科学及气象学]