不同情形下温度低于0 ℃时饱和水汽压的计算
Calculation of Saturated Vapor Pressure at Temperatures Below 0 ℃ Under Different Conditions
中文摘要：
利用2018年1月和5月长春站探空资料，通过理论分析和实例计算讨论了不同情形下、温度低于0℃时，如何合理地应用相对于水面和相对于冰面的饱和水汽压公式来计算饱和水汽压；计算了2018年5月29日实际大气的饱和比，分析了不同饱和比对应的云中饱和状况和粒子相态；结果表明：依据《常规高空气象观测业务规范》、数据计算和物理意义，可以整层采用相对于水面饱和水汽压公式计算大气可降水量；而讨论云粒子的形成、增长及产生降水的微观物理过程，需根据粒子的相态和粒子所处的周围环境来考虑应用哪种饱和水汽压公式；探空数据计算表明，实际大气中存在冰水共存相对于水面饱和、相对于冰面过饱和的环境；在400 hPa，云中存在水面欠饱和、冰面过饱和的环境。
中文关键词：
饱和水汽压，大气可降水量，异质核化，饱和比
KeyWords：
saturated water vapor pressure, precipitable water, heterogeneous nuclearization, saturation ratio
Abstract：
Using the sounding data at Changchun Station in January and May of 2018, theoretical analysis and case calculations are carried to discuss how to properly apply the saturated vapor pressure formulas to water and to ice when the temperature is lower than 0 ℃ under different conditions. The saturation ratio of the actual atmosphere on May 29, 2018 is calculated. The saturation state and particle phase of the cloud corresponding to different saturation ratios are analyzed. The results show that: according to the "Regular High Air Image Observing Service Specification", data calculation and physical meaning, the precipitable water can be calculated by only the saturated vapor pressure formula with respect to water; To discuss the formation, growth of cloud particles and microscopic physical processes of precipitation, it is necessary to consider which saturated vapor pressure formula should be applied according to the phase of the particles and the surrounding environment in which the particles are located; The calculation of sounding data shows that there is coexistence of ice and water in the actual atmosphere, where it is saturated with respect to water and supersaturated with respect to ice; there is an environment where is unsaturated with respect to water and is supersaturated with respect to ice at 400 hPa in actual atmosphere.