The Impact Of Global Sea Level Changes In The Law And The Specific Volume Change

Based on the TOPEX/Poseidon altimeter data, the characteristics of the seasonal variability of the global sea level is analyzed. It is suggested that the global sea level shows prominent seasonal variability, especially in the latitude band 15 0 N°640N, where the amplitude reaches 5-6cm and the latitude band 15 0 S°640S with the amplitude of 2-3cm.The maximal and minimal sea surface height (SSH) occurs in September and March respectively in the Northern Hemisphere, opposite to the Southern Hemisphere. The seasonal variability of the global sea level has the amplitude of about 1cm and the same phase with that of the Northern Hemisphere, which implies the dominant contribution of the Northern Hemisphere.The Ishii (2005) monthly mean temperature data is used to analyze the characteristics of the seasonal variability of the steric sea level. Similar to the result of the T/P data analysis, the signal of the variability is stronger in the latitude band of 15 0 N°640Nin the Northern Hemisphere where the amplitude is 4-5cm and in the same band in the Southern Hemisphere the amplitude is 2-4cm, and the phase of the variability in the two is opposite. However, the seasonal variability of the global mean steric sea level keeps synchronized with that of the Southern Hemisphere, which can be caused by the relatively larger heat content of the Southern Hemisphere.In the Northern Hemisphere, the seasonal variability of the mean steric sea level keeps in phase with that of the mean sea level obtained from T/P analysis and the contribution of the steric variability can reach 92%; In the Southern Hemisphere, the phase of the two is almost the same but the amplitude of the steric sea level variability is larger than that of the total sea level variability. The seasonal variability of the global mean steric sea level is in the opposite phase with that of the total sea level. In the basin scale, the variability of the sea level is in phase of that of the steric sea level in the Indian Ocean while in the Pacific Ocean their phases are opposite and in the Atlantic Ocean, there is a phase difference between the two kinds of variability. In the mid-latitude area, both the steric sea level and the sea level from T/P analysis present intense seasonal variability and the steric variability dominates the sea level change; in the low-latitude and high-latitude...