Analysis of global characteristics of annual and semiannual sea surface height abnormity fluctuations by using TOPEX/POSEIDON SSHA data

Since the TOPEX/POSEIDON satellite was successful launched on August 10, 1992, there has been the SSHA time series from the T/P altimeter data for almost ten years, yielding the level 2 data of 0.5 degrees x 0.5 degrees space resolution and 10 day's time resolution, and the level 3 data of 1 degrees x 1 degrees space resolution and 5 day's time resolution. We have analyzed, the SSHA time series from the T/P altimeter span from October 1992 to August 2002 to extract the information of the SSHA rising and annual and semiannual fluctuations of the SSHA variations with the space resolution of 1 degrees x 1 degrees by using wavelet technique. The results show that the global sea surface height raised about 24.2 mm in the last ten years, of which that of the Northern Hemisphere raised about 19.0 mm and that of Southern Hemisphere raised about 26.9 mm. The averages of the amplitude of the annual and semiannual variability of the global SSHA were 28.8 mm and 8.8 mm, respectively. The annual variation was larger than semiannual variation. The amplitudes of annual SSHA in the Northern Hemisphere and Southern Hemisphere were 40.3 mm and 21.1 mm, respectively. The amplitudes of semiannual SSHA in the Northern Hemisphere and Southern Hemisphere were 10.9 mm and 7.3 mm, respectively. The analysis also found the phase jump phenomenon of annual SSHA fluctuation in the southern and northern equator warm current regions.