Cloud type identification for a landfalling typhoon based on millimeter-wave radar range-height-indicator data

作者：Zhoujie CHENG,Ming WEI,Yaping ZHU,Jie BAI,Xiaoguang SUN,Li GAO

摘要：As a basic property of cloud,accurate identification of cloud type is useful in forecasting the evolution of landfalling typhoons.Millimeter-wave cloud radar is an important means of identifying cloud type.Here,we develop a fuzzy logic algorithm that depends on radar range-height-indicator(RHI)data and takes into account the fundamental physical features of different cloud types.The algorithm is applied to a ground-based Ka-band millimeter-wave cloud radar.The input parameters of the algorithm include average reflectivity factor intensity,ellipse long axis orientation,cloud base height,cloud thickness,presence/absence of precipitation,ratio of horizontal extent to vertical extent,maximum echo intensity,and standard variance of intensities.The identified cloud types are stratus(St),stratocumulus(Sc),cumulus(Cu),cumulonimbus(Cb),nimbostratus(Ns),altostratus(As),altocumulus(Ac)and high cloud.The cloud types identified using the algorithm are in good agreement with those identified by a human observer.As a case study,the algorithm was applied to typhoon Khanun(1720),which made landfall in south-eastern China in October 2017.Sequential identification results from the algorithm clearly reflected changes in cloud type and provided indicative information for forecasting of the typhoon.

发文机构：Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Beijing Institute of Aviation Meteorology Beijing Marine Hydrometeorologic Centre Beijing Meteorological Centre Taizhou Meteorological Bureau of Zhejiang Province

关键词：landfallingTYPHOONidentificationofCLOUDtypeMILLIMETER-WAVECLOUDradarRHIDATAfuzzylogic

分类号： TP3[自动化与计算机技术—计算机科学与技术]