西安东部夜间异常增温原因及其数值模式预报订正  

Mechanisms of Night Sudden Intense Warming Event in the East of Xi’an Area and Numerical Model Calibration Method

作　　者：刘嘉慧敏 薛春芳[3] 王建鹏 潘留杰[1,2] 张煦庭 郑然 黄少妮[1] 梁绵[1,2] LIU Jiahuimin;XUE Chunfang;WANG Jianpeng;PAN Liujie;ZHANG Xuting;ZHENG Ran;HUANG Shaoni;LIANG Mian(Shaanxi Meteorological Observatory,Xi'an 710014;Key Laboratory of Eco-Environment and Meteorology for the Qinling Mountains and Loess Plateau,Xi'an 710016;Shaanxi Meteorological Bureau,Xi'an 710014;Meteorological Institute of Shaanxi,Xi'an 710016;Sichuan Climate Center,Chengdu 610072)

机构地区：[1]陕西省气象台,西安710014 [2]秦岭和黄土高原生态环境气象重点实验室,西安710016 [3]陕西省气象局,西安710014 [4]陕西省气象科学研究院,西安710016 [5]四川省气候中心,成都610072

出　　处：《气象科技》2022年第1期66-74,共9页Meteorological Science and Technology

基　　金：国家重点研发计划专项资助(2018YFC1507901)。

摘　　要：利用陕西省气象监测站观测资料、NCEP/NCAR和ERA5全球再分析资料,对2019年12月10日凌晨西安东部一次夜间温度异常跃增过程进行深入分析。结果表明:(1)此次夜间增温过程发展迅速、局地性强、预报难度大。(2)500 hPa内蒙东部冷槽底后部干燥的西北气流和850 hPa干暖气团有利于产生大气下沉绝热增温。西安地区近地面存在逆温,阻碍大气热量的垂直交换。升温前西安东部2 m气温较周边地区显著偏暖,且维持时间长,为该地区夜间升温创造了有利条件。(3)西安东部低空长时间维持较强的暖平流,地面不断有弱冷空气侵入,加之受骊山阻挡,使得临潼地区近地面暖空气被急剧压缩,同时大气下沉绝热增温效应增强,在这四者的共同作用下造成了临潼地区夜间气温的显著跃增。(4)选取了近3年18次临潼地区夜间增温过程,对其进行天气系统、探空、垂直结构等深入分析,总结归纳临潼夜间增温发生判据,结合数值模式预报产品,提出订正方案,并进行检验评估。该方案有一定的正订正效果,可为数值模式对此类强转折性天气过程中气温精细化预报提供参考。Based on the data of meteorological stations over Shaanxi Province,NCEP/NCAR and ERA5 global reanalysis data,an in-depth analysis is conducted on the abnormal temperature jump process in the eastern part of Xi’an during the early morning hours of December 10,2019.The results show that:(1)This night sudden intense warming event developed rapidly and locally.It wasn’t easy to forecast.(2)The dry northwest airflow at 500 hPa and the dry warm air at 850 hPa were beneficial to the sinking adiabatic heating.There was inversion near the surface in Xi’an,which hindered the vertical exchange of atmospheric heat.The 2 m temperature in the east of Xi’an was significantly warmer than that in the surrounding areas.It lasted for a long time,creating favourable conditions for the nighttime warming in this area.(3)In this event,the adiabatic warming effect was strengthened with the eastward movement of the Xinjiang high ridge.The strong warm advection had been maintained in the lower layer of the eastern Xi’an area for a long time.In addition,because of the continuous invasion of weak cold air and the barrier effect of Lishan Mountain,the warm air near the ground in the Lintong area was compressed sharply.Under the four factors,the night temperature in the Lintong area increased significantly.(4)18 night sudden intense warming cases in the Lintong area are analyzed,and the occurrence criteria are summarized.The correction scheme is put forward and tested combined with the numerical model prediction products.The scheme has a positive correction effect in the Lintong area,providing a reference for the night temperature prediction.

关 键 词：夜间增温 下沉绝热增温 空气压缩效应 地形阻挡 

分 类 号：P456.1[天文地球—大气科学及气象学]