Annual cycle variations of the sea surface temperature (SST) in the Tropical Pacific Ocean between 20ºN and 20ºS for the period from 1854 to 2006 were studied using wavelet analysis. The study showed that the SST annual cycle, considered the variance around 1 year, contains interannual and interdecadal variabilities. There are indications that most of the SST annual cycle variations at Northern Hemisphere (NH) and at Southern Hemisphere (SH) areas is related to the El Niño-Southern Oscillation (ENSO) cycle. Most peaks of the localized Scale Average Power (SAP) for the 0.7-1.2 year scale for the areas on both hemispheres coincides with ENSO extremes. The Wavelet Power Spectra (WPS) shows maximum variance of the SST annual cycle between 120ºE and 140ºE for the northern hemisphere (NH) band (between equator and 20ºN), and eastward increasing variance from the dateline with a maximum between 100ºW and 80ºW for the southern hemisphere (SH) band (between equator and 20ºS). Therefore, the SST annual cycle presents variations between the NH and SH with the maximum variance being located in the eastern hemisphere for the NH and in the western hemisphere for the SH.
Annual Cycle of SST; Tropical Pacific; Wavelets
