The Research Of Severe Weather Based On Satellite Remote Sensing Data

Based on satellite remote sensing data two kinds of disaster weather were analyzed over northwest China. Based on satellite data of CloudSat, the effect of dust aerosol on cloud parameters under the circumstance of the monthly average, dusty days and dust-free days was analyzed during April,2010.Then using L2 aerosol profiles satellite data of CALIOP/CALIOPSO the aerosol extinction coefficients were analyzed over northwest China. With the keypoint of analyzing dust weather between 2013.4.16 and 4.18 over northwest China based on L1 satellite data of CALIOP/CALIOPSO as well as a combination of multiple satellite data and models, space distribution and transmission route of dust aerosol were analyzed. Finally using 2B satellite data of CPR/CloudSat cloud parameters of the moist season over northwest China was analyzed, meanwhile space distribution of cloud parameters was analyzed during the thunderstorm on 28th May,2007 over the middle part of Mt. Tianshan. The main conclusions are as follows:(l)By comparision of cloud parameters under the circumstances of the monthly,dusty days and dust-free days, it shows dust aerosol can reduce effective radius of particle, cloud liquid water content and cloud optical thickness, as wells as increase the number concentration of liquid cloud particles based on satellite data of CloudSat.(2) The aerosol extinction coefficient was decreased with the increase of height over northwest of China. The value of the aerosol extinction coefficient in desert was greater than the area in Gansu Province affected by urbanization. Distribution of the aerosol extinction coefficient in spring was nearly the same as the annual year.(3) Using aerosol classification products of the vertical characteristics from CALIOP/CALIOPSO, aerosol was classified during dust weather,and with NAPPS Global aerosol model, day distribution of the dust aerosol concentration was displayed showing the transport and diffusion of dust aerosol. With HYSPLIT trajectory model, dust transportation path of the sand dust source areas was showed on macroscopical. During the outbreak of dust weather dust aerosol was mainly distributed over the surface of 3km, with depolarization ratio at 0.4 and colour ratio at 1.2.During the dust weather weakened and even ended, dust aerosol was mainly distributed over the surface of 2kms, with depolarization ratio from 0.2 to 0.3, as well as colour ratio about 1.(4) During May to September of 2010, the cloud of northwest China was mainly single layer, while especially low and medium clouds. The cloud cover was increased first and then decreased with the increase of height,with an average of 80%. Overall, cloud microphysical parameters was increased first and then decreased with the increase of height, and the maximum of cloud parameters was founded at 3km. Cloud particle effective radius was founded reaching the maximum at 24μm, and the liquid number concentration of cloud was founded under 100 cm-3, and the cloud water content was founded reaching the maximum of over 150 mg·m-3. The maximum of cloud water content was corresponded with the large value area of the number concentration and effective radius of particles.(5) The analysis of storm case shows that:the peak area of the main cloud parameters was corresponded with water/ice clouds in the middle.The liquid water was mainly distributed over nimbostratus, altostratus and inside cumulus. The liquid water content was founded reaching its maximum to 245 mg·m3 at 3km. Number concentration of water particles was founded reaching its maximum below the lower part of the cloud liquid water and its minimum over higher level of the clouds. Effective radius of water particles was founded reaching its maximum at 23μm inside the middle part of liquid water, mainly distributed from 3.5km to 4km inside liquid water level. High value area of ice water content was founded over middle level of clouds while low values over the peak and the base of the clouds. Ice water content was started at 3km and increased in a nearly normal distribution with the increase of cloud level, as well as the peak at 6km. Number concentration of ice particles corresponded with ice water content was founded the high value area in the same place, reaching its maximum at 290 cm". Effective radius of high value area of cloud ice particle was mainly distributed under the lower level of ice clouds, reached its maximum at 120μm at the average of 5km, then decreased below and up 5 km.