A Comparative Analysis of the Kunming Quasi-stationary Frontal Position and Frontogenesis Function with Three Different Temperature and Humidity Parameters

This paper discusses potential temperature (PT), equivalent potential temperature (EPT), generalized potential temperature (GPT), and corresponding frontogenesis function during the weather process of Kunming quasi-stationary front (KQSF) in January and February 2008. Results are as follows. (1) Due to the large weighting factor of humidity in the GPT, it is not appropriate for analyzing the position and intensity of the KQSF, which is determined by temperature gradient. (2) In an ideal state, the dry atmospheric PT and the saturated atmospheric EPT are only related to temperature and pressure, and can better describe the characteristics of the atmospheric temperature field. Thus both PT and EPT can be applied for analyzing the KQSF, while the EPT can better describe temperature frontal zone. (3) Frontogenesis function calculated from PT or EPT can directly represent the situation of frontogenesis and frontolysis caused by changes in temperature, while the result of the GPT is able to indicate the temperature frontogenesis (frontolysis) and humidity frontogenesis (frontolysis) at the same time, yet it cannot be simply adopted to determine the front frontogenesis or frontolysis situation of the KQSF.