Avaliação de performance dos prognósticos de vento do modelo cosmo para Ilha da Trindade

Abstract

Weather forecasts are important for navigation in the South Atlantic. The objective of this work is to evaluate the performance of the COSMO numerical model for the 24h and 48h forecasts, referring to the initializations of 00Z and 12Z, of wind speed and direction on Trindade Island from January to December 2021. Pearson’s correction coefficient was used to arbitrate the methodology for extracting data from the model, because the grid points of the model do not coincide with the position of the island. The bilinear interpolation methodology was chosen over the nearest neighbor methodology. For performance evaluation, the statistical parameters RMSE, BIAS, Standard Deviation, as well as time series and frequency distribution were used. A preliminary analysis of the observed wind data was carried out in comparison with climatological data, which presented consistent results in most periods. The performance evaluations of the model in relation to the wind speed indicated that the model had difficulty in representing the wind with speeds lower than 3 m/s and higher than 12 m/s. The lowest values of velocity BIAS were observed when the observed wind had a velocity between 6 and 9 m/s. Regarding the wind direction, the model correctly represented the predominance of E wind, however, it presented difficulty in correctly accusing the SE wind frequency, probably due to the influence of the island’s relief. During the performance of frontal systems in the region of Trindade Island, the model did not correctly detect the wind that chaged from E to N, in most occurrences.