Using a 6-year June-July-August MODIS/Terra-measured cloud properties data set, the characteristics of clouds associated with the Asian summer monsoons are examined. The results indicate that a large amount of high clouds exists in the Indian monsoon region and account for approximately 65% of all cloud grids. Moreover, the interannual variation of high clouds is not apparent. In the East Asian monsoon region, high clouds show a relatively strong interannual variation and account for roughly 38.5% of all cloud grids. The overall percentages of middle and low clouds are comparable to each other within the East Asian monsoon region. Moreover three high cloud types have been identified to coexist in the Indian monsoon regions, i.e., cirrus, cirrostratus and deep convective clouds. Among them, cirrostratus has the largest percentage. In the East Asian monsoon region, the most frequently occurring cloud type is stratocumulus. However, compared with cloud climatology of surface observations, middle and low clouds are severely underestimated in the Asian monsoon regions by the MODIS/Terra measurements; in particular, the underestimation for low clouds is up to 80% in the Indian monsoon region. Therefore, great caution is needed when using the MODIS data to analyze middle and low clouds, especially when high and thick clouds exist. |