Some experiments to investigate the assimilation of SEASAT altimeter wave height data into a global wave model

Abstract

AbstractA scheme for assimilating SEASAT altimeter wave heights into a global wave model, with the additional use of the collocated altimeter wind speeds, is reported. Control experiments are described in which the wave model was run with two sets of winds, one with SEASAT scatterometer wind data included in the NWP analysis and the other without, both for a period from 0000 GMT 15 September 1978 to 0000 GMT 20 September 1978. the results of forcing the wave model with these wind fields are compared with the altimeter wave heights. the differences are discussed in order to quantify errors in both the wave model and the altimetric data. Three experiments in which altimeter wave heights were assimilated are then described. the results of these are compared with the wave fields from the model runs without wave data assimilation. the assimilation experiments show that a significant improvement in model wave height is possible and that the impact of one day of assimilation is retained for at least five days.