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近50a浙江省气候变化特征分析 总被引:45,自引:2,他引:45
用1951-1999年资料详细研究了浙江省4个观测站的年,季,月降水与气温的气候变化特征,提出了用蒙特卡洛(Monte Carlo)模拟方法对气象要素的的长期变化进行统计检验,指出,气候变化也可以出现在气象要素的变率上,提出了用计算滑动均方差的方法来识别这种变率异常的方法。 相似文献
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暴雨强度公式参数估计及其应用 总被引:7,自引:0,他引:7
利用最优化法实现非线性模型参数的数值解法 ,应用于暴雨强度公式参数估计 ,提高了公式参数估计的精度。该方法可广泛应用于多参数模式的优化问题 相似文献
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By using monthly NCEP/NCAR meridional gridpoint wind data at the levels of 1000, 850, 700,600, 500, 400, 300, 200, 150 and 100 hPa from 1948 to 2004, the intensity of global cross-equatorial flows is calculated. The spatial and temporal variation of global cross-equatorial flows at the 850-hPa level are shown and discussed. The results show that the strength of the 850-hPa global cross-equatorial flows represent obvious long-term variation and interdecadal change during the period. Evidence suggests that the cross-equatorial flow of the passages at 45 - 50 °E in June to August, 105 - 115 °E in May to September,130 - 140 °E in May to September and May to November and 20 - 25 °E in February to April intensified and that the cross-equatorial flow of the passages at 50 - 35 °W in June to August weaken in the past 57 years, with an increase of 0.25m/s/10a for summer Somali Jet and increase of 0.32 m/s/10a for crossequatorial flow at 130 - 140 °E in May to September The results of Singular Spectrum Analysis (SSA) for the time series indicate that for the cross-equatorial flow at 850 hPa, the interdecadal and long-term trend changes are 35% - 45%, and the interannual variation is no more than 30%, in variance contribution. The results also reveal that the interannual variation of intensity of the summer cross-equatorial flows in the Pacific is significantly correlated with Southern Oscillation. With weak Southern Oscillation, strong crossequatorial flows in Pacific will happen, though the summer Somali Jet is only a little positively correlated with North Atlantic Oscillation (NAD). 相似文献
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