The logarithm-linear relationship of the occurrence frequency to the duration of sand–dust storms: Evidence from observational data in China

The sand–dust storm data compiled by the China State Meteorological Bureau for the period of 1960–2000 have been analyzed to find the distribution of the sand–dust storm occurrence frequency against the duration time. It is found that there exists a universal relationship of , where N is the number of sand–dust storm occurrence frequency with the duration time greater than t, a and b are constants that may be associated with the sand–dust storm occurrence conditions at a given site. It is also shown that the constant b is related with surface conditions for the sand–dust storm occurrence with larger value of b less favorable for the occurrence of the sand–dust storm at that site. In fact, the large value of b is found in the Gobi and high-mountainous regions whereas the small value of b is found in the sand and dry loess regions.