Abstract:
Four types of sea surface wind data drifting buoy observation data, China Meteorological Administration (CMA) tropical cyclone database, ECMWF Reanalysis v5 dataset (ERA5), Cross-Calibrated Multi-Platform dataset (CCMP) are compared and analyzed during the super typhoon Lekima, and the comparision in sea surface wind characteristics between the ERA5/CCMP data and drifting buoy observation data is primarily discussed. The following are the main conclusions: (1) Characters of wind speed: ERA5/CCMP wind speed on the track of the drifting buoy is obviously lower than that of the drifting buoy observation when wind speed is less than grade 10. After the wind speed for the drifting buoy at 0.6 m is revised to 10 m, the Bias is smallest when the wind speed is less than or equal to grade 5 (−4.3 m s
−1 for ERA5 and −4.6 m s
−1 for CCMP) and largest when the wind speed is between grades 7 and 9 (approximately in the range of −9.2 to −10.2 m s
−1). The maximum wind speed of ERA5/CCMP near the center of Likima is less than that of the CMA tropical cyclone database; it is approximately 10.7 m s
−1 (4.6 m s
−1) for ERA5 (CCMP). The maximum wind speed of ERA5 (CCMP) is 54.5% (12.7%) lower than that of the CMA database. (2) Characters of wind direction: The correlation coefficient between ERA5/CCMP wind direction and the corresponding drifting buoy observation is almost 0. The wind direction is rightward than measured when wind speed is less than or equal to grade 5; otherwise, it is leftward than measured. (3) Wind direction and speed deviations between ERA5 and CCMP become obvious near the center of Lekima, but more consistency is observed considerably away from the center. Through further analysis of the ERA5 and CCMP data, we observe that CCMP can more clearly describe the wind field structure and evolution process of Lekima. Distribution of the wind structure parameter
η =
Vr/
Vmax appears like a closed-ring structure when Lekima is at the super typhoon level, meaning the presence of a large wind speed belt in this region. Typhoon forcing time
Tf is distributed on both sides of Lekima’s moving path. The maximum forcing time of ERA5 (CCMP) is 45 h (54 h).