Division of hydroclimatic area over China seas——Ⅰ. Principal component analysis

On the basis of oceanographic data over years of the China seas, 19 elements affecting the oceano-graphical climate are sorted out to make R-type principal component analysis. The first 6 principal synthetic factors are found with 91.06% of the accumulative ratio of their eigenvalue's variances to population variance, representing fullythe original information. In order to polarize the loading values of every principal factor tending to 1 or 0, varimax orthogonal rotation to the loading matrix of 6 principal factors is made.