| 摘要: |
| 利用常规地面、高空观测资料，灾情信息以及NCEP/NCAR、ECMWF再分析资料，对1999-2020年共22年发生在普洱市的10次低温冷害天气过程进行了分析，结果表明：（1）普洱市低温冷害天气过程可分为3类，不同类型高低层环流形势差异显著。（2）Ⅰ型以低温雨雪灾害为主，受南支槽和冷空气共同影响；期间欧亚中高纬度500hPa呈现为一槽一脊模态，东亚大槽由横转竖形成阶梯槽，并伴有南支槽稳定维持。（3）Ⅱ型过程开始至最强阶段主要造成低温雨雪灾害，最强至趋于结束阶段引发霜冻；期间欧亚中高纬度500hPa形势表现为两槽一脊模态，东亚大槽偏浅，南支槽为快速东移型。（4）Ⅲ型主要以低温霜冻灾害为主，无南支槽配合；期间欧亚中高纬度500hPa形势表现为两槽一脊模态，高压脊较强利于脊前西北气流下沉。（5）冷空气活动是3类低温冷害天气过程的共同特征，其差异主要表现在有无南支槽系统的配合；此外普洱市上空850hPa出现持续偏东北风、温度小于8℃，可以作为低温冷害，包括低温雨雪或低温霜冻产生的重要指标。 |
| 关键词: 普洱市；冬季低温冷害；南支槽；预报指标 |
| DOI： |
| 投稿时间：2022-10-10修订日期：2023-02-09 |
| 基金项目:国家自然科学基金项目 |
|
| Study on weather cases of low temperature and cold damage in winter in Pu"er City |
| wang fei |
| (Pu''er Meteorological Observatory) |
| Abstract: |
| Based on the conventional surface and high observation, disaster information, NCEP/NCAR and ECMWF reanalysis data, 10 weather cases of low temperature and cold damage occurred in Pu "er City in 22 years from 1999 to 2020 were analyzed. The results showed that: (1) The weather events of low temperature and cold damage in Pu "er city can be divided into three categories, and the circulation patterns of different types at high and low levels are significantly different. (2)Type Ⅰ is dominated by rain and snow disaster with low temperature, which are both affected by the south branch trough and cold air. During this period, the middle and high latitude of Eurasia shows a trough and ridge mode at 500hPa, and the East Asian trough shows a ladder trough from the transverse to vertical mode, accompanied by the south branch trough.(3)the type Ⅱ processes mainly caused rain and snow disaster with low temperature from the beginning to the strongest stage, and caused frost from the strongest stage to the end stage. During the whole period, circulation in the middle and high latitude of Eurasia at 500hPa shows the pattern of two trough and one ridge,The East Asia trough was shallow, and the southern branch trough was fast moving eastward.(4) Type Ⅲ is mainly caused low temperature frost disaster, without the cooperation of the southern branch trough, and the situation at 500hPa in the middle and high latitude of Eurasia shows the mode of two trough and one ridge, and the strong high ridge is conducive to the sinking of the northwest air in front of the ridge. (5) The activity of cold air is the common feature of the three kinds of cold weather events, and their difference is mainly manifested in the coordination of the southern branch trough system. In addition, the persistent northeast airflow at 850hPa over Pu "er City and the temperature is less than 8℃ can be used as an important indicator for low temperature and cold damage events, including rain and snow or frost with low temperature. |
| Key words: Pu"er city; Low temperature and cold damage in winter; South branch trough; Forecast factor |
