TOPEX/POSEIDON altimetry and dynamics of the ocean-atmosphere system

The T/P altimeter data 1993 - 1997 (cycles II - 194) has been analyzed with emphases on seasonal variations in sea surface topography (SST). The amplitude of the annual variations amounted to (5.9 +/- 0.3) mm when inverted barometer (IB) corrections were applied and (2.0 +/- 0.4) mm without airy IB corrections. The amplitude of the semi-annual variations in SST was small with IB corrections applied: (0.6 +/- 0.3) min. However, when Ilo IB corrections were applied it was (1.8 +/- 0.4) mm, i.e. the semiannual variations are at the same level as the annual variations with,lo IB corrections. The phase angle offset of the annual term has shifted by about 180 degrees when IB correction was applied. The dynamics of the ocean-atmosphere system is discussed and it is concluded that it could, at least partly be responsible for the above observed effects.