Recent increasing trend in dust frequency over Mongolia and Inner Mongolia regions and its association with climate and surface condition change

摘要

Trends in dust events over China and Mongolia were examined using 34 years (1974-2007) of visibility data over dust source regions of China and 10 years (1998-2007) of dust reports from Synoptic Observations (SYNOP) stations over China and Mongolia. Dust occurrences in Mongolia and northern Inner Mongolia increased over the 1998-2007 SYNOP data period while most dust source regions of China experienced a continuous decrease over the 34-year data period. Increased dust occurrences in Mongolia as well as in Inner Mongolia appear to be caused by degraded surface vegetation and reduced soil moisture associated with intensified drought conditions after the mid-1990s. Results suggest that recent increases in dust events over Korea and Japan are linked to increased dust occurrences over Mongolia and Inner Mongolia.