ON THE MEAN SEA SURFACE DATA IN THE GDR FILES OF THE TOPEX/POSEIDON, JASON-1, 2, AND 3 MISSIONS

Abstract. Altimetry satellites of the TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3 missions have provided the ocean study community with an unprecedented long-term time series of sea level observations from space. In this paper, we aim to investigate the mean sea surface (MSS) data given by the GDR files of the mentioned missions starting from the 1992 TOPEX/Poseidon mission to the latest GDR files of Jason-3. Due to climate change, it is expected that there be changes in the MSS value and furthermore, its trend is detectable in the time series of thirty years of mentioned altimetry observations. More specifically, we would like to know within long-term altimetry observations how the effect of sea level change is handled in the GDR files of TOPEX/Poseidon, Jason-1, 2, and 3 missions, and whether there are cares to be considered when using the MSS data given in the GDR files of these missions? Answer to this question and other related issues are discussed in the paper. Our benchmark for verifications of MSS data in the GDR files is the time series of the sea level heights (SSH) at 30 passes of the mentioned missions over the Baltic Sea.