Variations of 500 hPa flow patterns over Iranand surrounding areas and their relationship with the climate of Iran
Variations of 500 hPa flow patterns over Iranand surrounding areas and their relationship with the climate of Iran
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伊朗及周边地区500 hPa气流型变化及其与伊朗气候的关系
DOI：
10.1007/s007040200011
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发表时间：
2002
影响因子：
3.4
通讯作者：
B. Alijani
中科院分区：
文献类型：
--
作者：
B. Alijani
为了探索500 hPa流型的空间和时间变化及其与伊朗气候的关系，对0° E至70° E和20° N至50° N区域的月平均位势高度进行了5度分辨率的分析。研究期间涵盖了1961年至1990年期间的冬季10月至3月。500 hPa高度场沿25° N ~ 45° N各经沿着平均。月平均气压模式的高度与研究年份对应。结果表明：500 hPa流型特征在月尺度和年尺度上都有明显的变化，主成分分析采用S型和方差最大旋转的方法将网格化后的资料缩减为5个（10月为6个）显著因子。每个月的因子分数，然后与每月的Z分数的降水和温度异常伊朗。结果表明，靠近伊朗的海槽和海脊对伊朗气候的影响较大。两个海槽被确定并命名为里海和叙利亚海槽。
Summary In order to explore the spatial and temporal variations of 500 hPa flow patterns and their relationship with the climate of Iran, monthly mean geopotential heights for the region 0° E to 70° E and 20° N to 50° N, at 5 degree resolution, were analysed. The study period covered the winter months October to March during the period 1961–90. The monthly height of the 500 hPa level was averaged along each meridian from 25° N to 45° N. The height of the mean monthly pressure pattern was mapped against the study years. The results showed that the characteristics of the 500 hPa flow pattern varied over monthly and annual time scales.Principal Component Analysis, with S-mode and Varimax rotation, was also used to reduce the gridded data to 5 (6 in October) significant factors. The factor scores for each month were then correlated with monthly Z-scores of precipitation and temperature anomalies over Iran. The results showed that troughs and ridges located close to Iran had more influence on the climate of Iran. Two troughs were identified and named the Caspian and Syrian troughs.