An Analysis of the Structure and Variation of the Tropopause over China with GPS Radio Occultation Data

The status of the tropopause has impact on weather phenomena and climate change occurring in the atmosphere of the Earth. The investigation of structure and variation of the tropopause plays a significant role in an in-depth understanding of water vapour exchange, mass and chemical materials across the tropopause, and their impacts on climate change and ecological environment. With the advantages of high vertical resolution, global coverage, unbiased instrumentation, and long-term stability, GPS Radio Occultation (RO) data is ideal for the monitoring of tropopause structure. In this research, GPS RO data from the two missions, CHAMP and COSMIC, were used to assess and analyse the temporal and spatial variations in tropopause heights and temperature over China. The consistency of the precision of the GPS temperature profiles derived from the two missions were also statistically validated. The two types of tropopause, i.e. the Lapse Rate Tropopause (LRT) and the Cold Point Tropopause (CPT), were determined from the GPS RO temperature profiles, and the trend of the variations in tropopause heights and temperatures of the two types of tropopause were compared and analysed.