摘要
基于阻塞高压(阻高)客观识别方法,利用1979—2016年夏季(6—8月)NCEP-Ⅰ、NCEP-Ⅱ逐日再分析资料和ERA-interim逐6 h再分析资料对识别结果进行对比分析;并以D类(130°—160°E)阻高为例,讨论其对6月中国东北地区气候的可能影响。结果表明:NCEP-Ⅰ和NCEP-Ⅱ再分析资料对阻高活动天数、发生频次及年代际变化的识别结果差异较小,而ERA-interim与前两种资料的结果差别较大。3种再分析资料下,夏季各类阻高活动天数均与500 hPa高度场存在相应的显著相关区,且形态相近。但前两种资料对于各类阻高的表征结果较为一致,而ERA-interim再分析资料对各类阻高面积和范围的表征偏小。6月D类阻高活动日数与东北地区气温和降水关系密切,D类阻高活跃年,大气环流以经向型为主,东北地区低层低温、暖平流,高层高温、冷平流的结构指示大气层结不稳定,且东北上空为异常低压环流控制,上升气流较强,有利于6月东北地区出现低温多雨天气。鄂霍次克海地区是6月罗斯贝波的重要来源地之一,而6月D类阻高的形成可能与海-陆温差有关。
Using the blocking high objective identification method, the identification results based on daily reanalysis data of the NCEP/NCAR-Ⅰ, NCEP-Ⅱ and ERA-interim at 6 h intervals in the summer(June to August) for the period 1979-2016 are compared. Taking the type D blocking high as an example, we discuss its possible impacts on the climate in Northeast China during June. Results suggest that the reanalysis data of NCEP-Ⅰ and NCEP-Ⅱ show little difference in the identified number of days, frequency of occurrence and interdecadal variation of blocking high, while results from the ERA-interim reanalysis data are greatly different with results from the former two datasets. The three reanalysis datasets all indicate that there are areas where the number of various types of blocking high activity days is highly correlated with the height field of 500 hPa in the summer, and the patterns are similar between the three datasets. However, the characteristics of the results from the first two datasets for various types of blocking high are relatively consistent, while the characteristic area and range of blocking high from the ERA-interim reanalysis dataset is relatively small. The cumulative days of type D blocking high in June are closely related to temperature and precipitation in Northeast China. In the active years of type D blocking high, the atmospheric circulation is dominated by a meridional type. Low temperature and warm advection in the lower troposphere as well as high temperature and cold advection in the upper troposphere indicate an unstable atmospheric stratification. At the same time, abnormal low pressure circulation prevails over Northeast China, and the strong updraft is favorable for the formation of low temperature and rainy weather in Northeast China during June. The Okhotsk Sea area is an important source of Rossby wave in June, and the formation of type D blocking high in June may be related to the temperature difference between the sea and the land.
作者
刘刚
徐士琦
廉毅
LIU Gang;XU Shiqi;LIAN Yi(Laboratory of Research for Middle-High Latitude Circulation System and East Asian Monsson,Cangchun 130062,China;Research Institute of Meteorological Science of Jilin Province,Changchun 130062,China;Climate Center of Jilin Province ,Changchun 130062,China;Jilin Meteorological Information Network Center,Changchun 130062,China)
出处
《气象学报》
CAS
CSCD
北大核心
2019年第2期303-314,共12页
Acta Meteorologica Sinica
基金
国家自然科学基金(41741021
41630424
41530531
41875119)
中国气象局气候变化专项(CCSF201833)
关键词
阻塞高压
客观识别
资料对比
中国东北
Blocking high
Objective identification
Data comparison
Northeast China
作者简介
刘刚,从事天气气候研究等研究。E-mail:loverdream19991g@126.com;通信作者:徐士琦,主要从事气候变化及预测等研究。E-mail:xushiqi91@163.com.
