北半球平流层春季最后增温事件爆发日期定义方法的比较分析  

Comparison of the Methods in Defining the Onset of Stratospheric Final Warming Event during Boreal Spring

作　　者：刘翔宇 闫柳池 胡景高[1] 邓洁淳 李宗泽 何欢 Liu Xiangyu;Yan Liuchi;Hu Jinggao;Deng Jiechun;Li Zongze;He Huan(Key Laboratory of Meteorological Disaster,Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044;State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;University of Chinese Academy of Sciences,Beijing 100049;Nanjing CLIMBLUE Technology Co.Ltd.,Nanjing 211135)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心,南京210044 [2]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029 [3]中国科学院大学,北京100049 [4]南京创蓝科技有限公司,南京211135

出　　处：《气象科技进展》2024年第5期29-36,共8页Advances in Meteorological Science and Technology

基　　金：国家自然科学基金项目(42361144843,41975048,42175069);国家级大学生创新创业训练计划项目(202310300032Z)。

摘　　要：本文对定义北半球平流层春季最后增温事件(Stratospheric Final Warming,SFW)爆发日期的三种不同方法进行了比较分析。三种方法分别为:1)基于平流层极夜急流核心纬度带(60°--75°N)逐日纬向平均纬向风最后一次由西风转为东风的时间,简称为逐日风场反转法;2)将月平均纬向风场数据线性插值成逐日数据,然后基于插值后的逐日纬向平均纬向风由西风转为东风的时间,简称为月均风场插值法;3)90°N与60°N之间纬向平均温度经向梯度最后一次由负转正的日期,简称为温度梯度反转法。结果表明,由逐日风场反转法和月均风场插值法得到的SFW爆发日期基本一致,但是当平流层冬末和春初发生爆发性增温时,两种方法确定的SFW爆发日期易出现较大偏差;温度梯度反转法确定的SFW爆发日期早于逐日风场反转法确定的SFW爆发日期,在30 hPa等压面层,两种方法定义的平均日期相差16 d。由于逐日风场反转法在实际使用时更为常见,因此,以该方法为参考,对温度梯度反转法进行修订,结果表明,如果将温度梯度反转法中的阈值由0 K提高为3 K,以上利用温度和风场确定的SFW爆发日期则基本一致。This paper compares three methods in defining the onset of the boreal spring stratospheric final warming(SFW)events,which are based on the final reversal of daily circumpolar zonal wind direction(referred to as UD0),the reversal of zonal wind direction linearly interpolated from the monthly data(referred to as UM0),and the reversal of the meridional gradient of zonalmean temperature between the North Pole and 60°N(referred to as TG0),respectively.The SFW onset date identified by the UM0 method is basically consistent with that by the UD0 method.However,in the presence of major stratospheric sudden warming events in late winter and early spring,considerable discrepencies are discovered between the results of the two methods.The SFW onset date identified by TG0 tends to be earlier than that by UD0.At 30 hPa,The mean date of SFW by the TG0 method is~16 days earlier than that by the UD0 method.As the UD0 method is more common in practical use,the TG0 method is revised with this method as a reference.The research results show that if the threshold of the TG0 method is lifted from 0 K to 3 K,the SFW onset date in this method has excellent agreement with that by the UD0 method.

关 键 词：平流层最后增温事件 爆发日期 逐日风场反转 月均风场插值 温度梯度反转 

分 类 号：P4[天文地球—大气科学及气象学]