Global features and trends of the tropopause derived from GPS/CHAMP RO data

The global characteristics and trends of the tropopause physical parameters, height and temperature, obtained from the GPS/CHAMP radio occultation (RO) data in the period from Jul. 2001 to Oct. 2008, were modeled and analyzed in this work. The global distribution and variation of these parameters with latitude were estimated and analyzed using the Empirical Orthogonal Function (EOF), which was introduced to reveal the possible relationship between the tropopause variations and global climate change. The tropopause height and temperature varied with latitude. The results obtained by using the Empirical Orthogonal Function analysis suggested a recent rise in tropopause height and decrease in tropopause temperature; and also partly supported the argument that the global rise in the tropopause is consistent with global climate change. These results also revealed that the tropopause height increased mainly in the Polar regions, particularly in the South Polar region, as well as the regions where human activity is relatively significant, and decreased in the areas that are sparsely populated or have less human activity, such as the tropic region and south hemisphere. This paper also confirms that the GPS/LEO RO data are more reliable and can be effectively used to analyze the tropopause physical parameters.