THE CCA BETWEEN 500 hPa GEOPOTENTIAL HEIGHT FIELDS OVER NORTHERN HEMISPHERE AND RAINFALL OF CHINA IN MAY

Based on the theory of Canonical Correlation Analysis (CCA), the correlation between 500 hPa geopotential height (H) fields over the Northern Hemisphere (NH) and a 15-region rainfall (R) field of China in May is studied. The results indicate that: (1) there is a strong relationship between the H fields in January / May and the R field in China, (2) the variation of the general circulation over the whole NH (especially the 500 hPa H field over Europe and Asia) can affect the R in China, (3) in January and February the atmospheric general circulation can affect the R mainly by means of planetary waves, while in April and May the main control mechanism can be due to some teleconnections, and (4) the characteristic vectors for R in May and H from January to May have wave train structure, alternating sign from south to north.