Spatial and temporal variability of seasonal precipitation in Poyang Lake basin and possible links with climate indices
Spatial and temporal variability of seasonal precipitation in Poyang Lake basin and possible links with climate indices
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DOI：
10.2166/nh.2016.249
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发表时间：
2016-12
影响因子：
2.7
通讯作者：
Jun Shao;Jun Wang;S. Lv;J. Bing
中科院分区：
文献类型：
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作者：
Jun Shao;Jun Wang;S. Lv;J. Bing
利用鄱阳湖流域21个气象站的降水资料，采用小波分析方法，分析了鄱阳湖流域各季降水的时空变化特征。采用交叉小波变换分析了各季降水量与气候指标在时间和频率尺度上的相关性，探讨了其变化与气候指标之间可能存在的联系，并初步分析了其变化机制和规律。结果表明，鄱阳湖流域降水季节变化的主要周期为2-4年9和4-8年9波段的振荡。在2-4年波段中，鄱阳湖降水峰值出现的年份与厄尔尼诺出现的年份基本一致，夏季降水振荡在空间上表现得更为剧烈。不同季节降水量与气候指数的互小波功率谱分析表明，气候因子与季节降水量在特定时段存在一定的相关性。厄尔尼诺/南方涛动、北大西洋涛动、印度洋偶极子和太平洋年代际涛动等大尺度气候振荡通过各自独立或相互耦合的气候系统引起大尺度环流的变化，并通过改变东亚季风等局地气候条件影响鄱阳湖流域的降水分布。
Based on the precipitation data of 21 meteorological stations in Poyang Lake basin, the temporal and spatial variability of seasonal precipitation was analyzed by wavelet analysis method. This study adopted the cross wavelet transform to analyze the correlation between the seasonal precipitation and climate indices in time and frequency scales, discussed the possible links between its precipitation variations and climate indices, and preliminarily analyzed its mechanism and regular pattern of variation. The results showed that the oscillations in 2–4 years9 and 4–8 years9 bands were the main variation periods of seasonal precipitation in Poyang Lake basin. In the 2–4 years9 band, the years of rainfall peaks appearing in Poyang Lake were basically consistent with the years when El Nino appeared, and the precipitation oscillations in summer appeared more dramatic in space. According to analysis on the cross wavelet power spectra between different seasonal rainfalls and climate indices, certain correlations between climate factors and seasonal precipitation had existed in specific time periods. Large-scale climate oscillations like El Nino/Southern Oscillation, North Atlantic Oscillation, Indian Ocean Dipole, and Pacific Decadal Oscillation caused the variability of large-scale circulations through their respective independent or inter-coupled climate systems, and affected the precipitation distribution in Poyang Lake basin by changing the local climate conditions like the East Asian Monsoon.