Comparison of SVD and MEOF analysis on anomalous coupling relationship between temperature and precipitation in winter and summer in China
LI Liping;MA Chenyu;NI Yuman;YUAN Aijun;WANG Panxing;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster,Ministry of Education (KLME),Nanjing University of Information Science & Technology;School of Atmospheric Sciences,Nanjing University of Information Science & Technology;Anhui Meteorological Observatory;94995 Army Meteorological Observatory;
Taking study on the simultaneous coupling temporal and spatial characteristics between temperature and precipitation of China as an example in winter and summer respectively,the correlation relationship and equilibrium of the main orthogonal modes of SVD and MEOF analysis are compared,and the superiority of SVD method in revealing correlation relationship between two element fields is demonstrated.The main conclusions are as follows:(1)Comparing the principle of SVD with that of MEOF,the direct decomposition object of SVD is more pure and only contains information reflecting correlation relationship between two element fields,while that of MEOF also includes the autocorrelation information of two element fields itself,respectively.(2)The positive and negative anomalous distributions of the spatial coupled modes between air temperature and precipitation revealed by MEOF and SVD are approximately similar,but the main MEOF orthogonal modes between air temperature and precipitation in winter and summer are unbalanced compared with those revealed by SVD.That is,one of the main MEOF orthogonal modes often focuses on describing one of the two anomalous element fields.This difference is especially pronounced in winter.The SVD method reveals that the local high temperature and less precipitation or lowtemperature and more precipitation are the main abnormal configurations between temperature and precipitation in winter and summer over the same period in China,and the correlation is strong in summer and weak in winter.(3)By comparing the correlation coefficients and equalization of the same order orthogonal modes of SVD with those of MEOF,it is found that the correlation coefficients of most orthogonal modes of SVD are larger and more stable than those of MEOF,and all pass the significance test,and part of correlation coefficients of MEOF orthogonal modes in winter do not pass the significance test.The equalization of SVD main orthogonal modes is superior to that of MEOF analysis in winter,and is superior to(for the first mode)or close to(for the second and third modes)that of MEOF in summer.So the SVD method is a better way to reveal the coupling relationship between the two elements.
【Fund】： 国家重点基础研究发展计划(973计划)项目(2015CB453202);; 江苏高校优势学科建设工程资助项目(PAPD)
【CateGory Index】： P423;P426.6
【CateGory Index】： P423;P426.6