Study on the vertical distribution of precipitation in mountainous regions using TRMM data

The precipitation lapse rate (altitude effect of precipitation)and the zone of maximum precipitation in Tianshan and Qilian Mountains regions are studied using TRMM(Tropical Rainfall Measuring Mission)precipitation data.The results indicate that the annual TRMM precipitation compares well with the gauge observation over the two regions,the precipitation lapse rate and the zone of maximum precipitation can be quantified using the TRMM data.The annual precipitation in the Tianshan Mountain region is well correlated to the altitude over the two mountainous regions;the correlation coefficients are 0.90,0.81,and 0.58 on the Southern,Northern and Western slopes,respectively.The correspondmg multr-year average of precipitation lapse rates are 11.0 mm/100 m,6.3 mm/100 m,and 7.4 mm/100 m,and the zones of maximum precipitation on the three slopes are located at altitudes of 2200 to 3 500 m,3 200 to 3 700 m,and about 3 000 m,respectively.And in the Qilian Mountains region,the precipitation increase with the elevation,the effect of altitude on precipitation is more pronounced in the eastern part of the region compared to that of the western region.The precipitation lapse rate is 11.9 mm/100 m in the east,while,the zone of maximum precipitation is in the area with altitudes of 4 000 to 4 500 m.