Estudo comparativo entre dados de vento sobre o oceano Atlantico tropical estimados pelo satélite Metop-B/ASCAT e medidos pelas bóias do projeto PIRATA

Abstract

Sea surface winds have great relevance for scientific research. In the last decades, a large number of satellite missions carrying on-board scatterometer sensors were carried out with the aim of measuring these wind fields. Since September 2012, the MetOp-B/ASCAT operational satellite provides estimates of the wind field with spatial resolutions of 25 km and time resolution of approximately two daily measurements of the same area, but until the present there are few validation studies of these data, especially with respect to the wind direction. Therefore, this work presented a study comparing the data obtained by the MetOp-B/ASCAT satellite with observations obtained by ATLAS buoys system from the Prediction Research Moored Array in the Tropical Atlantic (PIRATA) project. The comparisons indicated that the wind speed and wind direction observed by MetOp-B/ASCAT agreed well with the data of the buoys. The mean square error of wind speed and direction were 0.91 m s−1 and 30.83◦ , respectively. The bias found for the wind data indicated that no significant dependence on the wind speed range is discernible. Time series of the wind speed data confirmed the correlation value found of 0.91, as well as highlighted the seasonal characteristics of the wind fields. In general, the results found validated the mission requirement for the wind speeds range from 3 to 30 m s−1.