1971-2009年珠穆朗玛峰地区尼泊尔境内气候变化

Climate change on southern slope of Mt. Qomolangma region in Nepal from 1971 to 2009

利用珠穆朗玛峰南坡尼泊尔境内(科西河流域)的10个气象站1971-2009年月平均气温、月平均最高、最低气温和逐月降水资料,采用线性趋势、Sen斜率估计、Mann-Kendall等方法分析区域气候变化状况及其时空特征,并与珠穆朗玛峰北坡地区气候进行比较,分析了珠穆朗玛峰地区气候变化的特征与趋势。结果表明:(1)1971-2009年间,珠穆朗玛峰南坡年平均气温为20.0℃,线性升温率为0.25℃/10a,与北坡主要受年平均最低气温影响相反,增幅主要受年平均最高气温升高的影响,并且在1974年及1992年间出现两次显著增温,增温特别明显的月份为2月和9月;(2)该地区降水变化的局地性较强,近40年间年平均降水量为1729.01mm,年平均降水量以每年约4.27mm的线性增幅有所增加,但并不显著,且降水月变化和季变化特征均不明显;(3)由于珠穆朗玛峰南坡受到季风带来暖湿气流和喜马拉雅山阻挡的双重影响,珠峰南坡的年平均降水量远高于北坡;(4)珠穆朗玛峰南坡气温变暖的海拔依赖性并不明显,且南坡地区的变暖趋势并没有北坡变暖趋势明显。

Based on monthly mean, maximum, minimum air temperature and monthly mean precipitation data from 10 meteorological stations on the southern slope of Mt. Qomolangma region in Nepal from 1971 to 2009, using climatic linear trend, Sen＇s Slope Estimates and Mann-Kendall Test analysis methods, this paper analyzed the spatial-temporal characteristics of climatic change in this region. It also made an comparative analysis with the northern slope of Mt. Qomoangma region to clarify the characteristics and trend of climatic change in the entire Mt. Qomoangma region. The results are shown as follows. （1） The annual mean temperature in this region during the period 1971-2009 was 20.0 ℃, and the rising rate of annual mean temperature was 0.25 ℃/10a. The temperature increase was mainly due to the maximum temperature rise in this region. On the contrary, the temperature increase of the northern slope of Mt. Qomoangma region was mainly owing to the minimum temperature rise. In 1974 and 1992, the temperature rose significantly, especially in February and September. （2） The precipitation had an asymmetric distribution; the annual precipitation was 1729.01 mm from 1971 to 2009. In this region the annual precipitation had an increasing rate of 4.27 mrrda, but it was not significant. Besides, the characteristic change of monthly or seasonal precipitation was not significant. （3） The annual precipitation in this region was more than that of the northern slope of Mt. Qomoangma region as the result of the combined influences of warm-wet flow and the Mt. Qomoangma barrier. （4） The dependence of climate warming on altitude is not significant in this region where the trend of climate warming is not as significant as that on the northern slope of Mt. Qomoangma.