冷空气影响前广州局地异常增温的诊断  

Diagnosis of an Anomalously Local Warming Incidence in Guangzhou Prior to Cold Air Effect

作　　者：罗曼宁 王硕甫 

机构地区：[1]广东省气象服务中心,广东广州510080 [2]佛山市气象局,广东佛山528000

出　　处：《广东气象》2015年第5期40-43,共4页Guangdong Meteorology

摘　　要：针对2015年1月6日冷空气到达广州前局地异常增温现象,利用逐时实测气温、MICAPS天气图分析天气背景发现,5日广州处于深厚的暖湿气流控制条件下,6日20:00后冷锋过境,则6日20:00前属于冷锋逼近时期。选用5日08:00—20:00和6日08:00—20:00时段的NCEPFNL再分析资料,借助热力学能量方程估算局地气温的平流项、垂直项大小,并由实测气温经过计算获得非绝热项的估算值。分析结果表明,冷锋逼近广州时非绝热项的贡献比例明显大于暖湿气流控制该地时非绝热项的贡献比例。通过对比分析这2个时段的非绝热项中天空状况、地形、下垫面性质、低空相对湿度和冷锋锋面移动5个影响因子的贡献情况,得出6日广州气温的异常增温与冷锋锋面的逼近密切相关。For an anomalously local warming incidence in Guangzhou prior to the arrival of cold air on January 6,2015,we used hourly observed temperatures and MICAPS weather maps to analyze its synoptic background. The finding is presented as follows. Having been controlled by a deep layer of warm and moist airflow on January 5,Guangzhou witnessed the passage of a cold front after 20: 00 on January 6. The time leading up to this point of time can be classified as one of cold front approaching. Two periods of NCEPFNL reanalysis data were selected,one from 08: 00 to 20: 00 January 5 and the other from 08: 00 to 20: 00 January 6,to estimate the values of the advection and vertical motion terms of local temperature with the aid of the thermodynamics equations. Then,the observed temperature was used to determine the estimated values of diabatic heating term. As shown in the result,the contribution of the diabatic heating term is much larger as the cold front gets close than during the dominance of the warm and moist airflow. By comparing and analyzing the contribution of five impact factors( sky conditions,terrain,underlying surface properties,low-level relative humidity and movement of the cold front) during the two periods of time,we came to the conclusion that the anomalously warming in Guangzhou on January 6,2015 was closely related with the approaching of a cold front at the surface level.

关 键 词：天气学 冷空气 增温 非绝热项 广州 

分 类 号：P423.35[天文地球—大气科学及气象学]