Characteristics of Observed Tropopause Height Derived From L-band Sounder Over the Tibetan Plateau and Surrounding Areas

The tropopause, which plays important roles in the stratosphere-troposphere exchange, is an interface between the troposphere and stratosphere. In this study, the characteristics of tropopause is investigated with the high vertical resolution daily sounding data during the period from 2008 to 2014 collected by the network of L-band sounder at 119 observational stations over Mainland China developed by the China Meteorological Administration (CMA). The results show that the tropopause height increases from the north to the south and has little correspondence with the station elevation. In addition, the spectral analyses and wavelet analyses are also performed to understand the intraseasonal variations of the tropopause. The results show that usually there are seasonal cycles with maximum in summer and minimum in winter. The strongest spectral band with period of 25-35 days is observed over the Southeast China. Besides, 20-60 days signals over the Changjiang River basin and the Tibetan Plateau has a good correlation to the Oceanic Nino Index (ONI), suggesting that the behavior of tropopause over the regions between 30 degrees N and 40 degrees N could relate to the Nino events.