Zonal distribution features of high frequency planetary waves in the oceans derived from satellite altimeter data

Based on TOPEX/Poseidon (T/P) and ERS-1 and 2 satellite altimeter data between October 1992 and December 2000,high frequency oscillations with periods less than 150 d are analyzed and their spatial distributions are described. Theratio, instead of the energy itself, of the energy corresponding to certain frequency band from power spectrun relative tothe total energy in the 20~143 d range is analyzed. The results show that the period of the most energetic oscillations inthis band increases with latitude from about 1 month near the tropics to about 4 months near 30°, in agreement with thelatitudinal dependency of the phase speed of westward propagating long Rossby waves,which dominate the variabilityin those latitudes. As a result,the global spatial distributions of the period of the dominant oscillations are largely zonal,with relatively small differences between different ocean basins. It suggests that the oscillations with periods around 60 d are mainly associated with planetary Rossby waves except the often regarded as tidal aliasing.