西北与华北地区现代降水变化趋势的对比

利用研究区内国家级气象站观测资料,分析1951~2013年降水变化趋势。其结果表明:西北与华北地区年均降水呈"东多西少"的空间格局;西北地区降水呈明显增加趋势,以青海及新疆西部较为显著,华北地区降水呈减少趋势,两地区降水趋势增加与减少的变化在104°E附近地区过渡;西北地区降水增加趋势起始于1980年代中期,华北地区降水减少趋势起始于1980年代初期;两地区降水变化"反(错)位相"特征在降水量累计距平百分比指标上表现明显。采用REOF方法,结合地理位置和地形等因素,西北与华北地区可分为6个降水子区域,各子区域及其之间的降水变化更详细体现出"反(错)位相"特征的情况,这种特征可能受到近几十年亚洲季风变化的影响。

Comparison of Recent Precipitation Tendency between Northwest and North China

Applying precipitation data from the meteorology stations during 1951-2013, the recent precipitation tendency between the Northwest and North China were analyzed. The conclusions are as follows: The spatial distribution of the annual precipitation is that the quantity is greater in the east than that in the west. The precipitation tendency is increasing obviously in the Northwest China, especially in Qinghai and Xinjiang, and the tendency is decreasing in the North China, the borderline between increasing and decreasing is nearby 104°E. The increasing tendency in the Northwest China started in the mid -1980s and the decreasing tendency in the North China started in the early 1980s. The anti -of -phase characteristics are also obviously by precipitation cumulative percentage anomaly. The whole area (Northwest and North China) is divided into six sub-regions related to different terrain, geographical position and circulation system, which can help to deeply understand the anti-of-phase characteristics in the Northwest and North China.