PROBABILITY DENSITY FUNCTIONS AND HIGHER ORDER STATISTICS OF LARGE-SCALE GEOSTROPHIC VELOCITY ESTIMATES AND SEA SURFACE HEIGHT, AS SEEN FROM THE JASON-1 – TOPEX/POSEIDON TANDEM MISSION

摘要

Geostrophic velocity Probability Density Functions (PDF), Skewness (S) and Kurtosis (K) are shown for both velocity components (u, v) estimated from the 3- year long Jason-1 - TOPEX/Poseidon (JTP) Tandem Mission which allowed infer both velocity components directly from the altimeter observations. To be comparable to previous results of velocity- (w) and SSH-PDF, we include the 18.5-year time series of SSH from the TOPEX/Poseidon, Jason-1 and Jason-2 (TPJJ) missions. The differences in the PDF of both velocity components are found to be evident, with a wider shape for the zonal velocity component due to the larger variability in zonal direction. Results confirm that the exponential shape of the global velocity PDF is a consequence of the spatially inhomogeneous EKE distribution over the global ocean. Only regions with a small variance in EKE, have Gaussian shaped PDF, however, normalizing each time series with their STD results in Gaussian PDF everywhere.