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91.
为了提高北疆地区雪深时空分布监测的准确性,以该区域48个气象站点2006年12月—2007年1月的月平均雪深观测数据为基础,通过分析月均雪深空间自相关性及其与经纬度、高程的相关性,结合MODIS雪盖数据构建了多元非线性回归克里金插值方法,插值获得了北疆地区较高精度的雪深空间分布数据。将插值雪深数据与普通克里金插值法、考虑高程为辅助变量的协同克里金插值法的预测结果进行比较,结果表明:1相对普通克里金和协同克里金方法,多元非线性回归克里金法的12月份雪深预测精度分别提高了15.14%和9.54%,1月份的提高了4.8%和6.7%;2由于充分利用了经纬度和地形信息,多元非线性回归克里金法的雪深预测结果可提供更多细节信息;3预测结果客观地表达了雪深随经纬度和地形变化的趋势,反映了积雪深度的空间变异性;4基于不显著相关的协变量高程的协同克里金插值法预测的雪深数据精度劣于普通克里金插值法的预测结果。 相似文献
92.
Diurnal Variation of Tropical Cyclone Rainfall in the Western North Pacific in 2008-2010 总被引:1,自引:0,他引:1 下载免费PDF全文
Diurnal variation of tropical cyclone (TC) rainfall in the western North Pacific (WNP) is investigated using the high-resolution Climate Prediction Center's morphing technique (CMORPH) products obtained from the National Oceanic and Atmospheric Administration (NOAA). From January 2008 to October 2010, 72 TCs and 389 TC rainfall days were reported by the Joint Typhoon Warning Center's (JTWC) best-track record. The TC rain rate was partitioned using the Objective Synoptic Analysis Technique (OSAT) and interpolated into Local Standard Time (LST). Harmonic analysis was applied to analyze the diurnal variation of the precipitation. Obvious diurnal cycles were seen in approximately 70% of the TC rainfall days. The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical depressions (TDs) exhibit the highest precipitation variation amplitude (PVA), at approximately 30%, while super typhoons (STs) contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage (more than 37%) is stronger than that in the developing (less than 20%) and sustaining (28%) stages. On the basis of location, the PVA of more than 35% (less than 18%) is the highest (lowest) over the high-latitude oceanic areas (the eastern ocean of the Philippine Islands). In addition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively. 相似文献
93.
Diurnal variation of tropical cyclone (TC) rainfall in the western North Pacific (WNP) is investigated using the high-resolution Climate Prediction Center’s morphing technique (CMORPH) products obtained from the National Oceanic and Atmospheric Administration (NOAA). From January 2008 to October 2010, 72 TCs and 389 TC rainfall days were reported by the Joint Typhoon Warning Center’s (JTWC) best-track record. The TC rain rate was partitioned using the Objective Synoptic Analysis Technique (OSAT) and interpolated into Local Standard Time (LST). Harmonic analysis was applied to analyze the diurnal variation of the precipitation. Obvious diurnal cycles were seen in approximately 70% of the TC rainfall days.
The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical depressions (TDs) exhibit the highest precipitation variation amplitude (PVA), at approximately 30%, while super typhoons (STs) contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage (more than 37%) is stronger than that in the developing (less than 20%) and sustaining (28%) stages. On the basis of location, the PVA of more than 35% (less than 18%) is the highest (lowest) over the high-latitude oceanic areas (the eastern ocean of the Philippine Islands). In addition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively. 相似文献
94.
MENG Wei-juan LE Gui-ming LIN Zhao-xiang ZHANG Yong YANG Xing-xing 《Chinese Astronomy and Astrophysics》2014
The variation of the number of coronal mass ejections (CMEs) with different angular widths in the period of 1996-2008 is analyzed statistically in this paper, together with a comparison of the feature of time variation between the number of CMEs with some typical angular widths and the number of sunspots. 相似文献
95.
利用上海天文台 40cm天体照相仪底片资料所提供的疏散星团M1 1天区 (团心距r≤2 5′)内的 785颗恒星的相对自行和成员概率 ,讨论了M1 1的CM图、年龄、距离、半径、光度函数、质量和分层效应 ,得到M1 1的距离为 1 659pc ,年龄为 (1 .8— 2 .2 )× 1 0 8年 ,半径约为 2 4 .5pc ,光度质量 4354M⊙ ,位力质量 50 0 0M⊙ ,在确定光度函数时 ,提出了一种考虑样本天区不完备的修正办法 ,以便从观测光度函数导出现时光度函数 .分析表明 ,作为一个中等年龄的疏散星团 ,M 1 1中的团星已表现出较明显的空间质量分层效应 ;而另一方面 ,尽管存在速度质量分层效应 ,但很不明显 相似文献
96.
97.
WANG Pu-jun HOU Qi-jun SHU Ping HUANG Yu-long GUO Zhen-hua LI Jin-long College of Earth Sciences Jilin University Changchun Jilin China Jilin Petroleum Company Songyuan Jilin China Daqing Petroleum Company Daqing HeiLongjiang China 《东北亚地学研究》2005,(Z1)
Volcanic rocks of the late Mesozoic are very important reservoirs for the commercial natural gases including hydrocarbon, carbon dioxide and rare gases in the northern Songliao Basin. The reservoir volcanic rocks include rhyolite, andesite, trachyte, basalt and tuff. Facies of the volcanic rocks can be classified into 5 categories and 15 special types. Porosity and permeability of the volcanic reservoirs are facies-controlled. Commercial reservoirs were commonly found among the following volcanic subfacies: volcanic neck (I1) , underground-explosive breccia (I3), pyroclastic-bearing lava flow (II3), upper effusive (III3) and inner extrusive ones (IV1). The best volcanic reservoirs are generally evolved in the interbedded explosive and effusive volcanics. Rhyolites show in general better reservoir features than other types of rocks do. 相似文献
98.
1纳税筹划的含义及其目的纳税筹划主要是指在国家政策的许可下,按照税收法律法规的立法导向,通过对筹资、经营、投资、理财等活动进行合理的事前筹划和安排,取得"节税"效益,最终实现企业利润最大化和企业价值最大化的一种经济活动。它主要是通过对纳税业务进行事先策划,制定一整套的纳税操作方案,从而达到节税的目的。税务筹划包含着两个层面的意思,从征税人的角度而言,他们要进行的是税收筹划;而站在纳税人的立场上,需要进行的则是纳税筹划。纳税筹划包括了避税、节税和转嫁几方面的内容。纳税筹划不是偷税,也不完全等同于避税或节税。它具… 相似文献
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