崇礼云顶冬奥赛场夜间增温事件的统计特征及其形成机制研究  

Statistical Characteristics and Formation Mechanisms of Night Warming Events at Yunding Winter Olympic Stadium in Chongli

作　　者：孔凡超 连志鸾 KONG Fanchao;LIAN Zhiluan(Hebei Meteorological Observatory,Shijiazhuang 050021)

机构地区：[1]河北省气象台,石家庄050021

出　　处：《大气科学》2022年第1期191-205,共15页Chinese Journal of Atmospheric Sciences

基　　金：国家重点研发计划项目2018YFF0300101、2018YFF0300104;河北省技术创新引导计划项目19975414D。

摘　　要：本文利用2018年11月至2019年3月、2019年11月至2020年3月期间的自动站资料,对发生在河北崇礼云顶冬奥赛场的夜间增温事件进行了统计分析,并基于地基微波辐射计、激光测风雷达、风廓线仪以及NCEP/NCAR逐6小时再分析资料探讨了夜间增温事件可能的形成机制。研究得出:云顶赛场11月至次年3月,夜间增温事件的发生概率高达76.9%,揭示了冬季夜间增温在云顶赛场是一种常见现象,同时增温次数和增温幅度均随站点海拔高度增加而减小。云顶赛场夜间增温的形成机制可归为四类,分别为垂直风切变造成的逆温层混合增温、焚风增温、整层下沉增温、中低层暖平流增温。其中第二、三、四类增温过程中,增温开始前谷内存在逆温时,谷底增温幅度可能会明显大于山顶,从而导致增温幅度随高度增加而减小。此外,山顶仅受第三类和第四类形成机制影响,而四类增温机制均可引发山谷增温事件,这也是增温事件发生频次随高度升高而明显减少的原因。Based on the observed data from automated weather stations during November 2018–March 2019 and November 2019–March 2020 at the Yunding Winter Olympic Stadium in Chongli,Hebei Province,nocturnal warming events at the stadium are statistically analyzed in this paper.Several possible formation mechanisms for these events are then discussed based on microwave radiometer,three-dimensional laser radar and the wind profiler data,and reanalysis data from NCEP/NACR.The results show that the occurrence probability of nocturnal warming events in Yunding Stadium reaches 76.9%from November to the following March,indicating that such warming events are a common phenomenon there.The frequency and amplitude of the warming decrease with increasing altitude.The triggering mechanisms of nocturnal warming events at Yunding Stadium can be classified into four categories:(1)mixed warming in the inversion layer caused by vertical wind shears,(2)Foehn-type warming,(3)whole-layer subsidence warming,and(4)warm advection in the mid and low levels.During the warming process of the second through fourth types,the warming amplitude at the bottom of the valley may be significantly larger than that at the top of the mountain when there is an initial temperature inversion in the valley.In this scenario,warming amplitude decreases with increasing altitude.The warming at the top of the mountain is only affected by the third and fourth types of formation mechanisms,while all four types can trigger warming events in the valley.This explains why the occurrence frequency of warming events decreases with increasing altitude.

关 键 词：夜间增温 形成机制 焚风 

分 类 号：P457[天文地球—大气科学及气象学]