A Study of Vertical Structure of Spring Stratiform Clouds in Northwest China

Observations from aircraft equipped with Particle Measuring System in May—June 2001,surface observations and satellite data have been analyzed to get macro and micro structures of cloud system over Northwest China,including cloud base height,cloud thickness,cloud particle concentration,liquid water content,effective cloud particle radius,and cloud particle spectrum function.The depth of stratiform clouds with precipitation is about 2000 m,The mean value of liquid water content of low clouds with precipitation is about 0.07 g·m~(-3),The mean value of liquid water content of middle clouds with precipitation is about 0.03 g·m~(-3).It is found that there are distinct differences between stratiform clouds with and without precipitation,by comparing their macro- and microphysics.The effective radius of stratiform cloud with precipitation needs to be as large as 10-16μm.