Temporal-Spatial Characteristics Of Precipitation Over The Tibetan Plateau

As all we know, the global climate which has been changing at higher pace than it used to be has brought deep influence on human beings in the past one hundred years. Under the global climate change, the regional climate change attracts much attention. The Tibetan Plateau is a typical area in the global climate system, its climate change possess sensitive response and strong effect to the global climate change. With EOF, REOF, linear regression, Wavelet analysis and coefficient analysis, the space-time characteristics, the precipitation coefficients between The Tibetan Plateau and India are studied by using the monthly precipitation data during 1961-2005 from 98 stations. The results show that:(1)There are two patterns of annual precipitation, dry-wet difference and dry-wet consistence. Dry-wet difference includes two kinds as follow: dry(wet)in south and wet(dry)in north, dry(wet)in southeast and wet(dry)in northwest. The first eight rotated loading vector fields represent eight principal annual precipitation anomaly areas.(2)There is an obviously positive trend with the precipitation during spring and winter, and no obvious trend in summer, autumn and annual. We found that there are 2-year, 7-year, 11-year, 22-year time scales and main periods of annual precipitation. 4-year, 7-year, 11-year, 28-year of spring precipitation. 4-year, 11-year of autumn precipitation. 3-year, 5-year, 11-year of winter precipitation.(3) The trends of precipitation have an obvious regional difference. For example, a decreasing trend appears in the southeast of the Tibetan Plateau but an increasing trend in the remaining area in winter.(4)The correlations of rainy season precipitation between the Tibetan Plateau and India as follows: There is positive relation between the south of the Plateau and Northeast of India, negative correlation between north of the Plateau and most area of India, also east of the Plateau and northeast of India.(5) The responds of glaciers, lakes and runoffs to the precipitation in the Tibetan Plateau are so complex that we can't simply conclude which leads to the change.