Study on altimeter-based inversion model of mean wave period

Based on the strong correlation between nondimensional wave height and wave age, we propose a quartic polynomial model by piecewise method according to significant wave height. In order to validate our new model, a validation dataset was created by interpolating the mean wave period data of ERA-40 to 23 cycles counterpart measuring points of Jason-1 altimeter with bilinear interpolation. We found that (1) the previous inversion models based on altimeter measurements cannot provide enough accuracy with our global validation dataset; (2) compared with H98 model, the RMS error and bias were reduced by 0.8949 s and 0.3759 s, respectively, by piecewise quartic polynomial model. Furthermore, the bias of the new model is -0.0197 s, which indicates that it offers enough accuracy in the global range.