Boundary Layer Dust Occurrence IV Atmospheric Dust Over Selected Geographical Areas

This is the fourth in a series of reports designed to provide a guide to the occurrence of atmospheric dust over selected geographical areas. Tabular data on the duration and on the diurnal and monthly variations in the probability of occurrence of blowing dust (visibility less than 11 km) and of dust storms (visibility less than 1 km) are presented for 45 stations which averaged at least 3.7 days per year (1%) with blowing dust. The 45 stations were geographically distributed as follows: Angola (2), Australia (1), China (1), Italy (1), Mali (13), Mauritania (11), Mexico (4), Niger (5), North Korea (1), Peru (2), South Korea (1), Spanish Sahara (2), and Venezuela (1). For 257 stations (in 35 countries) which averaged less than 3.7 days per year with blowing dust, tabular dust data are limited to the mean annual number of days with blowing dust and dust storms.