Abstract:
The interdecadal contrast characteristics of rainfall and temperature in China around 1976 and its affecting factors are analyzed by using the NCEP/NCAR reanalysis data and the surface air temperature/rainfall records from the 743 stations in China. The results show that, since 1976, the rainfall and the temperature in South China has been increased and decreased in spring, respectively, whereas the rainfall over the west part of the Yangtze River valley decreased. In summer, there existed a meridional “+,-,+, -” precipitation pattern in which there are more rains in South China and North China but less rains in the Yangtze and Huaihe River basins and Northeast China. It was found that a strong cooling occurs in the Yangtze River and the Huaihe River valleys in contrast to warming in the other regions in summer. The mean temperature in China shows an increasing trend evidently and the total amount of rainfall has a decreasing trend obviously in autumn. In winter, the consistent warming trend was showed almost in the whole China and an excessive rainfall in South China and the Yangtze River valley. The interdecadal decline of mean temperature in China is mainly due to the maximal temperature variation, while the rise mainly to the minimal temperature in and spring summer. The warming in fall and winter is mostly influenced by the minimal and maximal temperature variations, respectively. Possible causes for the interdecadal contrast change of the rainfall and temperature in China were closely related with the shift of the ascending and subsidence branches of the Hadley circulation, the intensification and migration of the westerly jet, the drywet conditions of the atmospheric layer, as well as the origin of water vapor transport.