Decadal change of the spring dust storm in northwest China and the associated atmospheric circulation

The decadal variations of spring dust storms in Northwest China and the associated circulation changes are investigated by using the station observations of dust storm frequency data of China and the NCEP/NCAR reanalysis data for the period 1960-2003. The domain-averaged, spring dust storm frequency index (DSFI) in Northwest China exhibits a decadal change, with a sharp decrease after the mid-1980s. The decreased frequency of spring dust storms in Northwest China after the mid-1980s is concurrent with enhanced geopotential height over the Mongolian plateau and Middle Siberia (MPMS) as well as an anomalous shift in the phase and intensity of the stationary wave over Eurasia. In addition, an increase in precipitation in the western region of Northwest China also contributed to the decrease in spring dust storms.