Analysis Of Cirrus Physical Properties Over Nanjing, China Based On The CloudSat And CALIPSO Satellite Data

The macroscopic and microscopic properties of cirrus are of great significance to the study of cirrus radiative forcing. CloudSat and CALIPSO belong to the A-train satellite system members, they cooperate with each other to achieve quasi synchronization on the same track, the observation of active and passive multi-band on the earth, which can provide detailed information on cloud microphysical properties. IWC (ice water content) is one of the most important microphysical properties of cirrus which provides a theoretical basis for the cloud character parameters in development and research of climate model. To study the macro and micro characteristics of cirrus over Nanjing, this paper uses combined detection data from CloudSat and CALIPSO, and uses three empirical formulas to propose a new method of joint inversion of cirrus IWC as well as conducts contrast and verification of retrieval results. In addition, the statistical analysis of cirrus in Nanjing area is also made. The main contents and conclusions of this paper are as follows:1) In this paper, we conduct comparison and validation of the retrieval results between joint inversion method (proposed by this paper) and space-borne radar,which demonstrates the combined inversion method is reliable, comprehensive, and accurate for cirrus of inversion. For the region detected by Lidar-only and Radar-only,the joint inversion method utilizes the measurable advantages of Lidar, which make the retrieval results comprehensive, effective and closer to actual value.2) In this article, we perform comparison and validation of the retrieval results between joint inversion method (proposed by this paper) and ground-based radar, by comparison and analysis, which verifies the combined inversion method achieves IWC cirrus of inversion effectively, comprehensively, reliably, and accurately again,and the retrieval results are superior to the outcomes retrieved by using the inversion method or detection data alone.3) We conduct statistic and analysis for the microphysical property of cirrus in Nanjing district by using the combine detection data product of space-borne radar.From January 2007 to December 2010, the occurence frequency of cirrus in the spring and summer are greater than autumn and winter during the four years ; the height of cloud base and top are near within the whole four years, and the maximum of the mean height of cloud base and top are 10.065km, 11.685km in 2009 respectively; the mean of IWC and ER (effective radius) are showed the tendency-increasing first and decreasing last yearly,and the minimum of the year mean IWC and ER are 0.0458g/m∧3,45.893μm respectively.