利用位于季风边缘区的青海地区分布的27个气象站1960—2008年间的逐年气温、降水资料,主要采用气候倾向率与相关性系数方法分析了青海省近49年的气温和降水变化。研究结果表明:位于季风边缘区的青海省在1960—2008年气温和降水整体呈增加的趋势。青海省西北地区和青海省东南地区气温、降水均呈增加的趋势。青海省西北地区比东南地区增温更明显,而青海省西北地区和东南地区降水变化幅度具有很好的一致性。青海省降水增加的高值中心都位于青南高原和祁连山区等海拔较高的地区,青海省降水增加的低值中心都位于柴达木盆地和河湟谷地等海拔较低的地区。不同海拔地区的降水差异可能与区域地形导致的上升下沉气流机制有关。
Linear slopes of instrumental temperature and precipitation data from 1960to 2008in Qinghai Province,China,were analyzed to observe their temporal trends by a T-test method.Our findings indicate that both temperature and precipitation exhibit an increasing trend with fluctuations during that period across Qinghai Province.In addition,temperature and precipitation variations are highly positively correlated.The long-term temperature and precipitation trends of southeast Qinghai Province(SEQP),which is mainly controlled by the summer monsoon,and those of northwest Qinghai Province(NWQP),which is dominated by the Westerlies,are generally in agreement,with both temperature and precipitation exhibiting a rising trend.In general,the amplitude of temperature changes in the NWQP is larger than that in the SEQP.However,the amplitude of precipitation changes in NWQP is close to that in SEQP.The core regions that exhibit an increasing precipitation trend are located in high-altitude areas,such as southern Qinghai Plateau and Qilian Mountains,while the regions with an insignificant increasing trend are located in low-lying areas,such as Qinghai Lake Basin and Qaidam Basin.The contrasting pattern may be a result of topography-induced uplifting and subsiding air dynamics.