基于MODIS云参数的卷云反射率计算研究  

Calculating the reflectance of cirrus clouds based on cirrus properties from MODIS

作　　者：赵凤美 戴聪明 魏合理 朱希娟[3] 马静 Zhao Fengmei;Dai Congming;Wei Heli;Zhu Xijuan;Ma Jing(School of Environmental Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Atmospheric Optics,Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences,Hefei 230031,China;Science and Technology on Optical Radiation Laboratory,Beijing Institute of Environmental Features,Beijing 100854,China)

机构地区：[1]中国科学技术大学环境科学与光电技术学院,安徽合肥230026 [2]中国科学院安徽光学精密机械研究所中国科学院大气光学重点实验室,安徽合肥230031 [3]北京环境特性研究所光学辐射重点实验室,北京100854

出　　处：《红外与激光工程》2018年第9期259-265,共7页Infrared and Laser Engineering

基　　金：国家自然科学基金(61077081);国防基础科研计划项目(JCKY2016204C602)

摘　　要：卷云反射率是天气、气候和地球能量平衡研究中关注的重要参数。卷云反射率的快速算法在遥感反演卷云特性参数中具有重要应用。依据卷云反射率随卷云光学厚度、有效尺度、太阳天顶角、观测天顶角、相对方位角等参数的变化,利用离散坐标法(Discrete Ordinate Radiative Transfer method,DISORT)计算卷云反射率,预先建立卷云反射率随相关参数变化的快速查找表,以此建立了卷云反射率的快速算法。将MODIS卫星探测的卷云光学厚度、太阳天顶角、观测天顶角、相对方位角等因素作为输入参数,计算得到了卷云反射率,比较了计算的卷云反射率和MODIS实际测量的卷云反射率值,相关系数达到0.94,平均偏差小于18.5%,说明了卷云快速算法计算合理可行。The reflectance of cirrus clouds is an important parameter in weather,climate and earth energy balance studies.The fast algorithm for calculating the reflectance of cirrus clouds plays an important role in the retrieval characteristics of cirrusclouds.Based on the variations of the reflectance of cirrus clouds with the relevant factors,such as cirrus optical thickness,effective particle size,solar zenith angle,observing zenith angle,the relative azimuth angle et al,a prepared Look-Up-Table(LUT)was developed by using DISORT to compute the reflectance of cirrus clouds.A fast algorithm for calculating the cirrus reflectance was established with utilization of the LUT.The cirrus reflectivity was calculated from the parameters of cirrus clouds,including cirrus optical thickness,effective particle size,solar zenith angle,observing zenith angle,the relative azimuth angle,which were read from the cloud products of MODIS.A comparison between the derived reflectivity with the proposed fast algorithm and the measured one was performed.The correlation coefficient is 0.94 and an average deviation is less than 18.5%.The result indicates that the fast algorithm for calculating cirrus reflectance is reasonable and feasible.

关 键 词：卷云 反射率 计算 MODIS 

分 类 号：P401[天文地球—大气物理学与大气环境]