Abstract:

Based on the NCEP/NCAR reanalysis data with 2.5°×2.5° spatial resolution and the monthly temperature anomalies and precipitation anomaly percentage from weather stations in the Tibetan Plateau during 1971-2010, three-dimensional E-P flux was calculated, firstly. On this basis the characteristics of planetary waves were analyzed by using harmonic analysis and synthesis analysis method, and the preliminary relationship between the planetary wave anomalies and temperature, precipitation in the Tibetan Plateau and surrounding areas was explored. The results showed that there was three-centres including Asia Europe, North America and North Atlantic for the propagation of the quasi-stationary planetary wave, and that spread to lower latitudes and the polar at 50°N in the horizontal direction, respectively. Planetary wave anomalies had some relation with temperature and precipitation in the Tibetan Plateau and surrounding areas. When the wave guide of low-latitude in winter was strong during 1971-2010, the temperature was lower than the normal in the Tibetan Plateau, Northwest China, Guangdong and Guangxi region and the middle reaches of the Yangtze River, while that was higher than the normal in Southwest China, Loess Plateau and the central of Inner Mongolia. At the same time, the precipitation was more in eastern Tibet Plateau, the south of Northwest China, the north of Southwest China, the middle reaches of the Yangtze River and Guangdong, Guangxi, but that was fewer in western Inner Mongolia and Yunnan Province. When the wave guide of low-latitude was weak from 1971 to 2010, the temperature was lower than the normal in northeastern of Tibet Plateau, the Yangtze River basin and Guangdong, Guangxi, while that was higher in most parts of Southwest China. Meanwhile, the precipitation increased in Inner Mongolia and decreased elsewhere.

Key words: Tibetan Plateau, Planetary waves, E-P flux

摘要：

利用1971～2010年NCEP/NCAR再分析资料和中国752个基本站温度距平与降水距平百分率资料，计算了三维E-P通量，借助谐波分析和合成分析方法分析行星波的整体特征，探讨行星波异常与青藏高原及周边地区气温、降水的初步关系。结果表明：行星波的传播主要有亚欧、北美和北大西洋3个垂直传播中心，在水平方向上主要以50°N为界分别向低纬度和极地地区传播。行星波异常与青藏高原及周边地区气温、降水有一定的相关关系。冬季，当低纬度波导偏强时，青藏高原、中国西北、长江中游和两广地区气温偏低，西南地区、黄土高原和内蒙古中部地区气温偏高；青藏高原中东部、中国西北地区南部、西南地区北部、长江中游和两广地区降水偏多，内蒙古西部及云南降水减少。当低纬度波导偏弱时，青藏高原东北部、长江流域和两广地区气温偏低，西南大部气温偏高；内蒙古降水增多，其他地区降水减少。

关键词: 青藏高原, 行星波, E-P通量