关键词: 极端最低气温天气过程, 对比分析, 定量估算, 局地温度

Abstract: Based on MICAPS data and NCEP (1°×1°) reanalysis data, the weather backgrounds of two extreme minimum temperatures (January 15, 2010 and January 6, 2010) were analyzed, including circulation situations, the vertical structure of physical quantity field, advection term and vertical term as well as non-adiabatic term of temperature equation etc.. The results indicate that the circulation situations of two processes are similar, and both also impact directly North China from the northwest. Cold advection moves horizontally and descends vertically. According to quantitative evaluation of various factors of the local temperature, the effect of increasing temperature does not ignore when air is dry and downward airflow is prevailing from lower level to high level. The extreme minimum temperature on January 6, 2010 is mainly influenced by non-adiabatic factors. Snowstorm happens on January 3-4, 2010 in Qinhuangdao, and depth of snow cover is above 10 cm. Non-adiabatic terms on January 6 and January 15, 2010 are -0.907°C•h^-1 and -0.301°C•h^-1, respectively. The changes of underlying surface could influence the local temperature, which could provide references for the minimum temperature forecast.