摘要
根据冻雨发生时特定的地面温度、地面湿度及高空温度三个基本特征,定义了中国冻雨潜在发生指数(FRGPI)并进行了初步验证。在此基础上利用欧洲中心ERA-Interim再分析及模式预报产品,结合2013/2014年冬季冻雨发生情况,对中国冻雨潜在发生指数进行了推广应用。结论如下:2014年2月上旬,高空槽、中低层切变线、低空急流及暖湿气流的共同作用,造成了中国南方产生冻雨的适宜的地面温度t、温度露点差D及高空温度层结Er,因此出现大范围冻雨灾害。2月中旬贵州受西南低涡及暖湿气流影响,也产生了适宜的t、D及Er条件,遭受了持续性冻雨灾害。2013/2014年冬季期间,适宜冻雨的温度t集中在冬季寒潮过程中0℃等温线所在地区,温度露点差D集中在西南暖湿气流影响区域,高空温度层结Er集中在中高纬与低纬天气系统交界地带;三部分交叉区域则为冻雨高发地带,且地面温度露点差可能是制约冻雨分布的主要因素。将FRGPI指数与欧洲中心数值预报产品相结合发现,可以提前10 d有效地对冻雨灾害进行预报,对防灾减灾有一定的实用性。
Based on the specific three basic characteristics of surface temperature, surface humidity and upper air temperature when freezing rain occurs, freezing rain genesis potential index (FRGPI) of China was defined and verified preliminarily. And using ERA-Interim reanalysis and model forecast prod- ucts, and combining with the cases of freezing rain in winters of 2013/2014, this article gave a further development and application of freezing rain genesis potential index. Results were as the followings, due to the interaction of the upper trough, mid-low-level shear-line, low-level jet and warm and wet flow, the southern China maintained suitable surface temperature t, depression of dew point temperature D, and upper air temperature stratification Er, the large-scale freezing rain disaster occurred in early February 2014. Under the influence of southwest vortex and warm and wet flow, Guizhou province also had suitable t, D and Er and then suffered continuous freezing rain disaster in mid-February. During the winter of 2013/2014, the suitable t which was favorable to freezing rain was located in the area where surface tem- perature was close to the freezing point in winter cold wave. The suitable D was mainly in the area where warm and wet flow occurred. The suitable Er mainly located in the strongly interaction area between mid- rile-high latitude and low latitude. The overlapping area had highly occurrence frequency of freezing rain, and the surface depression of dew point temperature maybe the key factor influenced its spatial distribution. The freezing rain can be forecasted 10 days before by using FRGPI and Medium-Range Weather Forecasts (ECMWF) forecast products of the European Centre, which was benefit for freezing rain disaster prevention and mitigation.
出处
《气象与环境科学》
2015年第2期92-101,共10页
Meteorological and Environmental Sciences
基金
公益性行业(气象)科研专项(GYHY201406017)
全球变化研究国家重大科学研究计划项目(2015CB953904
2012CB955604)
国家自然科学基金委员会-山东省人民政府联合资助海洋科学研究中心项目(U1406401)资助
关键词
冻雨
冻雨潜在发生指数
ECMWF模式
预报
freezing rain
freezing rain genesis potential index
ECMWF model
forecast