应用河西走廊敦煌、酒泉、张掖、民勤四站2006-2015年5-10月逐日07：00（北京时，下同）和19：00探空资料，分析0℃层高度的变化特征，以及与干湿、降水、灾害天气的关系。结果表明：0℃层高度与日极端气温、0 cm最低地温关系最为密切，日极端气温地温越高，0℃层高度越高，在19：00相关性最好，系数大于0.95；温度露点差（T-Td）值与日降水量、日最低气温和0 cm最低地温成反相关，而与气温日较差成正相关，最大相关系数大于0.7。河西0℃层高度在3300~5000 m，气压在680~560 hPa，T-Td在10~17℃，早上低而湿，夜间相反。干湿天气对比中，干天气时0℃层高度高且早晚变化明显，19：00较高；而湿天气时T-Td早晚变化明显，07：00较小。有降水时，0℃层高度在3000~4800 m，气压在750~570 hPa，T-Td < 8℃，07：00 T-Td < 6℃；昼夜变化中夜间降水07：00高度低，而白天降水19：00高度低。不同降水量级中，T-Td从小到大为大雨、中雨和小雨，相应最大值分别为2℃、5℃和9℃。雷暴0℃层高度在3600~4900 m，气压在660~560 hPa，T-Td ≤ 7℃。风沙天气0℃层气压在700~540 hPa，沙尘暴0℃层高度7-9月07：00明显较高，7-8月达5000 m以上；沙尘暴天气出现时早上干而夜间湿，19：00 T-Td < 5℃，因而汛期沙暴多发生在午后且伴有降水。≥ 35℃高温天气0℃层高度在4600~5300 m，气压在570~530 hPa，T-Td ≥ 13℃。

In order to provide reference for the forecast of disastrous weathers, based on daily sounding data at 07:00 (Beijing time, after the same) and 19:00 from May to October at four stations of Dunhuang, Jiuquan, Zhangye and Minqin over Hexi Corridor during 2006-2015, the variation characteristics of 0℃ isotherm height as well as its relationships with dry-wet, precipitation and disastrous weather were analyzed. The 0℃ isotherm height is most closely related to the daily extreme temperature, 0 cm minimum ground temperature; the higher the extreme air temperature and ground temperature is, the higher the 0℃ isotherm height is, and the best correlation is between the 0℃ isotherm height and 0 cm minimum ground temperature at 19:00, the coefficient of which is greater than 0.95. The value of temperature and dew difference (T-Td) is inversely correlated with daily precipitation, daily minimum air temperature and 0 cm minimum ground temperature, but is positively correlated with the daily temperature range, and the maximum correlation coefficient is greater than 0.7. The 0℃ isotherm height over Hexi Corridor was 3300~5000 m, the atmospheric pressure was 680~560 hPa, the T-Td was between 10~17℃, the height was low and wet in morning, but which was opposite at night. In dry and wet weather contrast, dry weather 0℃ isotherm height was high, obvious morning-evening variation and higher at 19:00, while the morning-evening variation of T-Td was obvious and more humid at 07:00 in wet weather. When precipitation occurred, the 0℃ isotherm height was 3000~4800 m, the atmospheric pressure was 750~570 hPa, T-Td < 8℃, and T-Td < 6℃ at 07:00; in day-night variation, low 0℃ isotherm height occurred at 07:00 in nighttime rainfall, while which occurred at 19:00 in daytime precipitation. In different precipitation levels, the maximum values of T-Td from light rain, to moderate rain and heavy rain were 2℃, 5℃ and 9℃, respectively. Thunderstorm 0℃ isotherm height was 3600~4900 m, the pressure was 660~560 hPa, T-Td ≤ 7℃. In gale and sand-dust weather, 0℃ isotherm pressure was 700~540 hPa, sandstorm 0℃ isotherm height at 07:00 from July to September was higher 300~500 m than that of gale and sand-dust, which was above 5000 m from July to August. When sandstorm occurred, it was dry at 07:00 but wet at 19:00 when T-Td < 5℃, so sandstorm in flood season often occurred in the precipitation afternoon. In daily maximum temperature ≥ 35℃ high temperature weather, 0℃ isotherm height was 4600~5300 m, the pressure was 570~530 hPa, T-Td ≥ 13℃.