Wet season Mediterranean precipitation variability:: influence of large-scale dynamics and trends
Wet season Mediterranean precipitation variability:: influence of large-scale dynamics and trends
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DOI：
10.1007/s00382-004-0422-0
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发表时间：
2004-08-01
期刊：
影响因子：
4.6
通讯作者：
Wanner, H
中科院分区：
文献类型：
--
作者：
Xoplaki, E;González-Rouco, JF;Wanner, H
在几个对流层水平的大尺度大气环流对整个地中海地区的292个站点的雨季降水的影响进行了评估。采用基于经验正交函数和典型相关分析的客观方法设计了一个统计降尺度模型，并通过交叉验证进行了检验。在所有30%的总地中海10月至3月降水的变化可以解释为四个大规模的位势高度场和海平面气压的组合。地中海海表温度似乎是不太相关的，以解释降水的年际时间尺度的变化。结果表明，第一CCA模态的年代际变化与北大西洋涛动指数的变化有关，并对整个世纪地中海降水的可比时间尺度变化负有责任。分析表明，自世纪中期以来，降水量稳步增加，在1960年代达到最大值，此后有所减少。世纪后半叶，总的趋势是月（-1）旬（-1）下降2.2毫米。
The influence of the large-scale atmospheric circulation at several tropospheric levels on wet season precipitation over 292 sites across the Mediterranean area is assessed. A statistical downscaling model is designed with an objective methodology based on empirical orthogonal functions and canonical correlation analysis (CCA) and tested by means of cross-validation. In all 30% of the total Mediterranean October to March precipitation variability can be accounted for by the combination of four large-scale geopotential height fields and sea level pressure. The Mediterranean sea surface temperatures seem to be less relevant to explain precipitation variability at interannual time scale. It is shown that interdecadal changes in the first CCA mode are related to variations in the North Atlantic Oscillation index and responsible for comparable time scale variations of the Mediterranean precipitation throughout the twentieth century. The analysis reveals that since the mid-nineteenth century precipitation steadily increased with a maximum in the 1960s and decreased since then. The second half of the twentieth century shows a general downward trend of 2.2 mm.month(-1).decade(-1).