新疆铁门关市高温气候特征及其环流形势分析

An Analysis of the High Temperature Climatic Characteristics and Its Circulation Situation of Tiemenguan City in Xinjiang

摘要: 利用新疆生产建设兵团第二师铁门关国家气象观测站1961~2017年的最高气温初日、最高气温终日及5~9月的逐日最高气温等观测资料和NCEP 1˚ × 1˚再分析资料，针对铁门关市高温天气的气候特征及其环流背景进行了综合统计和分析。结果表明：1) 新疆生产建设兵团铁门关市近57 a的平均高温日数为30 d，主要集中出现在7月中旬至8月上旬，占总高温日数的42.9%。2) 铁门关市的高温日数具有较为明显的年代际变化，2008年为最多高温年份，高温日数为46 d；最少年出现在1993年，仅有10 d。3) 铁门关市的高温分布整体呈逐年上升趋势，近16 a上升趋势较为明显，高温日数增多，且高温天气的持续时间和强度都呈现逐渐增强的趋势。4) 在500 hPa高度场上，铁门关市的持续高温天气过程主要表现为四类环流形势：新疆脊控制型、伊朗副高东伸发展型、伊朗副高与新疆脊共同影响型、伊朗副高与西太副高形成的两高对峙型。其中，伊朗副高与新疆脊共同影响型则极有利于极端高温天气(Tmax ≥ 40℃)的出现。高温持续时间与副高的强度和位置有着十分密切的联系，当副高强、范围大，则对应的高温天气强度大，且持续时间长、影响范围广。

Abstract: Using the observation data and the NCEP 1˚ × 1˚ reanalysis data taken from the first day with the recorded highest temperature, the last day with the recorded highest temperature, and the day-by-day maximum temperature from May to September between 1961-2017 of the Tiemenguan National Meteorological Observatory under the Xinjiang Production and Construction Corps 2nd Di-vision, a comprehensive statistics and analysis on the climatic characteristics and circulation back-ground of the high temperatures in Tiemenguan City was carried out. The results indicate that: 1) The average number of days with recorded high temperatures near 57 a of Xinjiang Production and Construction Corps in Tiemenguan City is 30 days, concentrated mainly from mid-July to early Au-gust, and accounts for 42.9% of the total number of days with recorded high temperatures; 2) The number of days with recorded high temperatures in Tiemenguan City shows obvious interdecadal variations. The year 2008 had the longest number of days with recorded high temperatures, name-ly 46 days while the year 1993 had the shortest number of days with recorded high temperatures, with only 10 days; 3) The distribution of days with recorded high temperatures in Tiemenguan City increases every year. The rising trend is more evident near 16 a, with an increase in the number of days with recorded high temperatures, as well as a gradual increase in the duration and intensity of the hot weather; 4) In the 500 hPa height field, the continuous hot weather in Tiemenguan City is mainly represented by four types of circulation: the Xinjiang ridge control type, the Iranian sub-tropical high east extension development type, the joint influence type of Iranian subtropical high and Xinjiang ridge, and the two high confrontation types formed by the Iranian subtropical high and the west Pacific subtropical high. Among them, the joint influence types of Iranian subtropical high and the Xinjiang ridge are extremely conducive to the emergence of extreme high temperature (Tmax ≥ 40˚C). There is a strong correlation between the duration of high temperature and the intensity and position of the subtropical high. When the subtropical high is stronger and the scope is larger, the corresponding hot weather is more intense, lasts longer and has a wider influence.