Influence of Dust Storm Frequency in Northern China on Fluctuations of Asian Dust Frequency Observed in Japan

Abstract

Relationship between Asian dust frequency observedin Japan (ADF) and dust storm frequency (DSF) innorthern China was examined with up-to-date longtermobservational data. Possible climatic conditions associatedwith variations of ADF were also explored. Itwas found that DSF at stations in Inner Mongolia andits vicinity (IMV) and ADF behaved nearly parallel toeach other from the mid 1970s. Significant positive correlationbetween DSF in IMV and ADF suggests thatIMV has a stronger influence on ADF than other dustsource regions in northern China. Composite maps ofSea Level Pressure and 700 hPa wind fields for extremeADF years exhibited a spatial pattern with cyclonicanomalies over the area from Northeast China to northJapan and anticyclonic anomalies around the Gobidesert in high ADF years. This situation corresponds toenhanced cyclonic activities in Northeast China and intensifiedcold air outbreaks in IMV, which are favorablefor formation of dust storms in IMV.