两标准化场SVD第一模态解释方差80%是正常的么？

cream4230

1. 
   
2. <P>%***********************Z500**********************
   
3. fil1='D:\2015\NCEP\hgt.mon.mean.nc';
   
4. z500=ncread(fil1,'hgt',[1 1 6 1],[Inf Inf 1 Inf]);
   
5. z500=squeeze(z500);
   
6. z12=z500(:,:,12:12:end);</P>
   
7. <P>z1=z500(:,:,13:12:end);
   
8. z2=z500(:,:,14:12:end);
   
9. z_win=(z12+z1+z2)./3;
   
10. zzz=z_win(:,1:29,13:56);%1960-2003 20N-90N 冬季500hpa
    
11. %*******point*time*****
    
12. pointZ=size(zzz,1)*size(zzz,2);
    
13. mz=zeros(pointZ,44);
    
14. for i=1:44
    
15. mz(:,i)=reshape(zzz(:,:,i),pointZ,1);
    
16. end
    
17. 
    
18. %**********************印度洋SST*******************
    
19. fil1='D:\2015\NOAA\sst.mnmean.nc';
    
20. sst=ncread(fil1,'sst',[1 1 1],[Inf Inf Inf]);</P>
    
21. <P>sst12=sst(:,:,12:12:end);
    
22. sst1=sst(:,:,13:12:end);
    
23. sst2=sst(:,:,14:12:end);
    
24. sst_win=(sst12+sst1+sst2)./3;
    
25. sss=sst_win(19:61,33:55,107:150);%1960-2003 (20S-24N，36E-120E) 冬季sst
    
26. %***point*time****
    
27. pointSST=size(sss,1)*size(sss,2);
    
28. msst=zeros(pointSST,44);
    
29. for i=1:44
    
30. msst(:,i)=reshape(sss(:,:,i),pointSST,1);
    
31. end
    
32. 
    
33. %*****************缺测********************
    
34. [m2,n]=size(msst);
    
35. b=find(msst(:,1)>-99692);
    
36. nb=find(msst(:,1)<-99692);
    
37. 
    
38. % 用有意义的X和Y做SVD
    
39. mmsst=msst(b,:);
    
40. [m2_real,n]=size(mmsst);
    
41. 
    
42. %-------- 标准化 --------------------------
    
43. norm_h500_before=zeros(pointZ,44);
    
44. norm_sst_before=zeros(m2_real,44);
    
45. 
    
46. for i=1:pointZ
    
47. norm_h500_before(i,:)=(mz(i,:)-mean(mz(i,:)))./std(mz(i,:));
    
48. end
    
49. for i=1:m2_real
    
50. norm_sst_before(i,:)=(mmsst(i,:)-mean(mmsst(i,:)))./std(mmsst(i,:));
    
51. end
    
52. 
    
53. %------------ SVD hgt500 and SST ----------
    
54. X_before=norm_h500_before*norm_sst_before';
    
55. [U2,S2,V2]=svd(X_before);
    
56. lam=diag(S2);
    
57. total=sum(lam.^2);
    
58. SCF=lam.^2/total; % 方差贡献率
    
59. </P>

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利用如上步骤进行SVD分解，得到SCF(1)为85%，但是文献中一般前两个模态SCF一共解释70%~80%，但找不到问题所在，希望做过SVD的前辈们给一点建议~

liuyichao629

正常的！！！！！！！！！！