Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-03-13 Cooperative journals: 《干旱区研究》
Abstract： Based on the observation data of daily precipitation and temperature elements in winter from 1978 to 2020 from 17 national meteorological stations, the spatial- temporal variation characteristics of winter snowfall and its relationship with meteorological factors in the economic belt on the north slope of the middle Tianshan Mountains were analyzed by using various statistical methods. The results show that: The regional distribution of snowfall days and snowfall amount is similar, showing the distribution characteristics of‘more urban areas, less mountainous areas’. The decrease of light snow days is the direct reason for the decrease of total snow days, while the significant increase of moderate snow and blizzard is the main reason for the increase of total snowfall. The precipitation process lasting for 1 day is the main snowfall process in winter. With the increase of the duration, the precipitation process decreases significantly, and the precipitation process ≥ 5 days only accounts for 2.8%; In the past 43 years, the climate on the north slope of Tianshan Mountains has shown an obvious warming and humidifying trend. In 1987 and 1994, the amount of snowfall changed from less to more and the average temperature changed from lower to higher; The amount of snowfall is significantly and positively correlated with the annual precipitation, the average minimum temperature in winter, and the number of snowfall days. The greater the annual precipitation, the lower the minimum temperature in winter, and the more snowfall days, the greater the amount of snowfall in winter, and vice versa.
Subjects: Geosciences >> Geography submitted time 2019-11-15 Cooperative journals: 《干旱区地理》
Abstract：利用常规气象观测资料、NCEP/NCAR 1°×1°（美国气象环境预报中心—NCEP和美国国家大气研究中心—NCAR）再分析资料、全球同化系统(GDAS)数据、引入基于拉格朗日方法的气流轨迹模式（HYSPLIT_v4.9）、FY-2E卫星资料、多普勒雷达产品，对2014年2月和2016年3月天山北麓的两次暴雪天气过程进行了诊断分析。结果表明：两次暴雪过程的降雪落区均是出现在500 hPa槽前、低层切变或辐合区、高层辐散区、温度平流梯度在垂直方向大值区、相当黑体亮度温度(TBB)中心边缘的梯度较大处重叠区域。通过诊断发现，2016年暴雪天气的暴雪区上空有类似于暴雨过程的湿对称不稳定存在，使得大气潜在不稳定能量较大，为暴雪提供了不稳定机制。而在2014年暴雪天气中没有发现湿对称不稳定，说明条件对称不稳定并不是造成暴雪的唯一原因，还可能受别的不稳定机制或动力因子、热力因子影响，但其对单位时间内降雪强度有明显的增幅作用。分析雷达回波特征的演变发现，雷达回波中心的强度、持续时间、范围与强降雪中心的变化一致。
Hits
Hits
Downloads
Comment