sand-dust storm weather processes arctic vortex midlatitude westerly concentration-weighted trajectory method
Supported by the Special Project on PublicWelfare of Forestry (200804020), National Science and Technology Support Program of China (2008BAC40B02), National Natural Science Foundation of China (40875077), National Basic Research and Development (973) Program of China (2011CB403404 and 2011CB403401), and Projects of the Chinese Academy of Meteorological Sciences (2010Z002, 2009Z001, and 2009Y002).
YANG Yuanqin Atmospheric Composition Observation & Service Center, Chinese Academy of Meteorological Sciences, Beijing 100081
WANG Jizhi Atmospheric Composition Observation & Service Center, Chinese Academy of Meteorological Sciences, Beijing 100081
NIU Tao Atmospheric Composition Observation & Service Center, Chinese Academy of Meteorological Sciences, Beijing 100081
ZHOU Chunhong Atmospheric Composition Observation & Service Center, Chinese Academy of Meteorological Sciences, Beijing 100081
CHEN Miao Yunnan University, Kunming 650091
LIU Jiyan Nanjing University of Information Science & Technology, Nanjing 210044
The characteristic distributions of regional sand-dust storm (SDS) weather processes over Northeast Asia from 1980 to 2011 were investigated using the shared WMO surface station meteorological data, atmospheric sounding data, China high density weather data, NCEP/NCAR reanalysis data, as well as the archived original weather maps of China. The concentration-weighted trajectory (CWT) method was used to calculate the SDS frequency from the discrete station data and to track the large-scale regional SDS weather processes in Northeast Asia. A spline trend analysis method was employed to investigate the variability of the SDS weather systems. The results show that during 1980–2011, the SDS weather processes exhibit both a historical persistence and abrupt transitions with an approximate 10-yr high-low occurrence oscillation. Through composite analysis of atmospheric circulation during high and low SDS years, it is found that the SDS occurrences are closely related to the anomalies of arctic vortex and midlatitude westerly, and the circulation patterns around the Lake Baikal. During the high frequency years, the meridianal flows in the upper and mid troposphere above the high SDS corridor in East Asia (from the Lake Balkhash along Northwest and North China, Korean Peninsula, and Japan Islands) are apparently stronger than the meridianal flows during the low SDS frequency years, favoring the development and transport of SDSs in the midlatitude regions.