景德镇市大雾天气特征分析

使用景德镇市气象要素观测资料、气候统计资料和常规天气图等资料，采用统计学方法和特征提取等方法，就景德镇市大雾的气候特征及天气形势配置进行分析，结果表明：大雾多出现在冬半年，11～4月份出现频率较高，一天中雾起时间多出现在后半夜至凌晨，以05：00-07：00居多，大雾消散以08：00～09：00居多，最小能见度越低，持续时间越长；地面形势以孤立弱高压型和冷空气扩散型为主，占总数近七成；孤立弱高压型大雾在华东、江南为孤立大高压脊，高空500hPa赣东北为西北偏西气流，中低层受高压控制；冷空气扩散型大雾在河套以西为1030hPa左右的较强高压中心，冷空气由河套以西向东南方向扩散，赣东北处高压底部，等高线较密集，受850hPa弱高压脊、冷空气和辐射降温共同影响出现大雾。

Analysis on synoptic characteristics of dense fog in Jingdezhen City

By using the data of meteorological elements, climatological statistics and routine synoptic charts, the climatic characteristics of dense fog and synoptic situation in Jingdezhen City are analyzed based on the method of statistics and feature extraction. The results show that there are often dense fog in winter, the highest frequency of occurrence is center on November to March during 5-7 BJT in a day. The heavy fog occurs during after midnight to before dawn, disappearing at 8-9 BJT. The minimum of the visibility is smaller, the duration of the fog is longer. The surface synoptic situation mainly shows weak isolate high pressure and cold air diffusing, occupying 70% of the total. The fog produced by weak isolate high pressure shows isolate large high-pressure ridge in the east of China and the south of the Yangtze River. In the northeast of Jiangxi Province where west-northwest air current is in 500hpa layer. The high pressure is controlled in the middle-low level layer. The fog produced by cold air diffusing appears in 1 030hpa strong high pressure center along the west of Hetao area. The northeast of Jiangxi Province is located at the bottom of high pressure where isoheights are intensive. So the dense fog appears under the effect of weak high-pressure ridge, cold air and radiation cooling.