奎玛流域中下游阵风锋时空特征分析

Analysis of the Temporal and Spatial Characteristics of Gust Fronts in the Lower Reaches of the Kui-Ma River Basin

摘要: 本文利用2009~2018年昌吉州中西部(奎玛流域中下游)5个国家站、42个区域自动气象站及12个兵团气象站4~9月逐时观测资料和多普勒天气雷达资料，统计分析了该区域大风天气过程及阵风锋的时空分布特征。结果表明：(1) 近10a昌吉中西部共出现8级以上大风135次，年平均13.5次，年际变化明显；大风主要发生在5~7月，中部大风频次多于西部；(2) 基于有限样本(n = 23)的初步统计显示，共筛选出23次阵风锋过程，其年际变化无明显趋势，4~9月呈单峰型分布，6月最多，4月和9月最少；(3) 阵风锋主要发生在16:00至次日00:00，其中傍晚至前半夜(20:00~02:00)发生最多；阵风锋平均维持时间夏季最长，7月可达110 min以上，且傍晚至前半夜维持时间较长。研究结果可为奎玛流域下游雷暴大风和阵风锋的监测预警及短时临近预报提供参考。

Abstract: Based on the hourly observations from 5 national stations, 42 regional automatic weather stations and 12 meteorological stations of the Xinjiang Production and Construction Corps in central-western Changji (the middle and lower reaches of the Kui-Ma River Basin) from April to September during 2009~2018, combined with Doppler weather radar data, the temporal and spatial distribution characteristics of gale weather processes and gust fronts in this region were statistically analyzed. The results show that: (1) A total of 135 gale events with instantaneous wind speeds of no less than 17.2 m/s (wind force grade 8 or above) occurred in central-western Changji over the past 10 years, with an annual average of 13.5 events, showing an obvious interannual variation; gales mainly occurred from May to July, and gales were more frequent in the central region than in the western region. (2) Based on a limited sample (n = 23), preliminary statistics identified 23 gust front processes, showing no obvious interannual trend and a unimodal distribution from April to September, with the highest frequency in June and the lowest in April and September. (3) Gust fronts mainly occurred from 16:00 to 00:00 the next day, with the highest frequency from evening to the first half of the night (20:00~02:00); the average duration of gust fronts was the longest in summer, exceeding 110 min in July, and the duration from evening to the first half of the night was relatively longer. These results can provide a reference for the monitoring, early warning and nowcasting of thunderstorm gales and gust fronts in the lower reaches of the Kui-Ma River Basin.