Precipitation patterns in flood season over China associated with the El Niño/Southern Osciliation     

Budong Qian 《中国地理科学(英文版)》1997,7(3):220-228

The precipitation patterns in flood season over China associated with the El Niño/Southern Oscillation (ENSO) are investigated, especially in the eastern China, using the rather long period rainfall data in this century. The results show that there were remarkable differences between the precipitation patterns in flood seasons of ENSO warm phase (El Niño year) and cold phase (La Niña year), as well as between the patterns in El Niño years and their following years. The most parts of China received below normal rainfall in flood season of the onset years of El Niño events, but the coastal area of Southeast China received above normal amounts. Comparatively, the most parts of China received above normal rainfall in flood season of the following years of El Niño events, but the eastern part of the reaches among the Huanghe (Yellow) River, the Huaihe River and the Haihe River, and the Northeast China received less. During ENSO cold phase, the reaches of the Changjiang (Yangtze) River and the North China received more amounts than normal rainfall in flood season of the onset years of La Niña events, and the other regions of China received less. In the following years of La Niña events, the coastal area of the Southeast China, the most part of the Northeast China and the regions between the Huanghe River and the Huaihe River received more precipitation during flood seasons, but the other parts received below normal precipitation.  相似文献   

过渡季节(6—7月)澳大利亚冷高压对赤道辐合带形成的影响     

邓良焱  薛惠娴 《热带海洋学报》1993,(4)

应用车贝雪夫多项式分析过渡季节(6—7月)澳大利亚冷高压与赤道辐合带的关系,得出了对赤道辐合带北移的主要形势以及过程演变特征,最后用合成方法得到它的演变概念模式,为赤道辐合带的北移影响西太平洋及南海地区提供了中期预报的依据。  相似文献   

周期浅析     

战淑芸  杨淑瑞 《海洋预报》1992,9(4):47-51

本文分析了滑动平均的数据处理方法对周期分析结果产生的影响。提出了过程变量同号积分的数据处理方法,并对亚洲西风指数序列进行了试验分析。分析结果表明,周期的长短与振幅的大小有密切关系,亚洲逐日西风指数的周期振荡具有明显的季节特征。  相似文献   

不同季节的企鹅珍珠贝游离珠植核效果比较   总被引：7，自引：1，他引：7  

毛勇  梁飞龙  余祥勇  叶富良 《海洋通报》2003,22(6):88-91

在雷州流沙港湛江海洋大学珍珠研究室实验基地分别于春、夏和秋季进行了企鹅珍珠贝游离珠植核实验。其中，春季插核的死亡率最低，为15.1％--16．2％，留核率最高，为10％左右：而夏季插核的死亡率最高，为63．56％，留核率也仅为2．22％：秋季插核的留核率最低，仅收珠1颗，留核率为0．35％，死亡率也较高，为54.4％。结果表明，春季是企鹅珍珠贝较适宜的插核季节。  相似文献   

青岛浮山野生花卉种质资源   总被引：2，自引：0，他引：2  

李宝华  张建福 《海洋湖沼通报》1996,(4):74-84

本文简要叙述了青岛浮山野生花卉的种类、生长环境、园林用途及开花结果日期，为把这些野生花生花卉引进城市园林提供科学依据。  相似文献   

The First Appearance of Cattle in Denmark Occurred 6000 Years Ago: An Effect of Cultural or Climate and Environmental Changes     

Nanna Noe-Nygaard  Mikkel U. Hede 《Geografiska Annaler: Series A, Physical Geography》2006,88(2):87-95

Stable carbon and nitrogen isotope ratios from bones of contemporaneous Late Atlantic aurochs and early cattle in eastern Denmark are significantly different and provide information on the origin and feeding strategies of the earliest domestic cattle. The data show that the early cattle were feeding on grass right from the beginning 4000 cal. yr BC. In contrast, the youngest aurochs population primarily browsed and grazed from the dense forest floor resulting in rather negative δ¹³C values measured on bone collagen. The oldest aurochs have similar isotope values to the earlier cattle, whereas the youngest aurochs have similar values to Late Atlantic red deer from the same locality. As eastern Denmark was largely covered by forest, speculations on the origin of the grazing areas are many. The grass may have grown in openings in the forest, at the forest fringe, or more likely on the newly reclaimed coastal land areas exposed by the decreasing rate of eustatic sea‐level rise contemporaneously with isostatic uplift, during the Littorina transgressions. The stable isotope values do not indicate that leaf foddering of the early cattle was of importance.  相似文献   

华南前汛期不同降水时段的特征分析   总被引：41，自引：5，他引：41  

池艳珍  何金海  吴志伟 《南京气象学院学报》2005,28(2):163-171

利用1957-2001年华南地区74个测站逐日降水资料和同期NCEP／NCAR逐日再分析格点资料，对华南前汛期(4-6月)不同降水时段的特征进行了比较。分析发现，华南前汛期降水由锋面降水和夏季风降水两个时段组成。锋面降水时段主要集中在4月，为典型的由冬到夏过渡的环流形势，华南地区高空为平直的副热带西风急流，大气层结稳定，水汽来源主要是阿拉伯海的西风输送和西太平洋副高南侧东风的转向输送；南海夏季风爆发前，副高仍控制南海地区，华南地区水汽输送主要来源于阿拉伯海的西风输送和西太平洋副高南侧东风的转向输送及孟加拉湾的西南输送；南海夏季风爆发后，副高东撤退出南海地区，南半球越赤道水汽输送加强并与孟加拉湾水汽输送连通，华南区域内对流发展；夏季风降水时段盛期主要集中在6月，此时南亚高压跃上高原，华南地区处于南亚高压东部，对流发展极其旺盛，强大的南半球越赤道水汽输送越过孟加拉湾和南海地区向华南地区输送。  相似文献   

新疆北部降水的气候分布特片及其对ENSO的响应   总被引：1，自引：2，他引：1  

魏香  陈菊英 《地球物理学进展》2002,17(4):753-759

分析研究了新疆北部地区近50年（1951-2000年）全年各月降水的气候分布特征和各季降水的年际变化规律，重点揭示了北疆多雨季节（4-7月）及其各月降水量对赤道东太平洋的海温SST和南方涛动指数SOI的显著响应关系，并用前期SST和SOI作为预报因子，建立了北疆地区雨季水量的预报方程。该方程可用于北疆地区雨季降水量的长期预报。  相似文献   

Water discharge changes of the Changjiang River downstream Datong during dry season     

ZHANG Erfeng  CHEN Xiqing  WANG Xiaoli 《地理学报》2003,13(3):355-362

Based on hydrometric data and extensive investigations on water-extracting projects, this paper presents a preliminary study on water discharge changes between Datong and Xuliujing during dry season. The natural hydrological processes and human factors that influence the water discharge are analyzed with the help of GIS method. The investigations indicate that the water-extracting projects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000, with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction from the Changjiang River has become the most important factor influencing the water discharge downstream Datong during dry season. The potential magnitude in water discharge changes are estimated based on historical records of water extraction and a water balance model. The computational results were calibrated with the actual data. The future trend in changes of water discharge into the sea during dry season was discussed by taking into consideration of newly built hydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had a great influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a net decrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It is expected that the water extraction will continually increase in the coming decades, especially in dry years, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/s and will give a far-reaching effect on the changes of water discharge from the Changjiang into the sea.  相似文献   

华北汛期降水异常与100hPa高度场异常的关系   总被引：4，自引：1，他引：4       下载免费PDF全文

孙燕  王谦谦  钱永甫  张友姝 《气象科学》2003,23(4):418-425

利用华北17站1951～2000年的逐月降水资料,与前期的100 hPa高度场(1958～1997年)求相关,找到了100 hPa高度场影响华北地区汛期降水的关键影响区为25°～35°N,85°～105°E,对应的关键影响时段为前一年3～5月.然后用SVD方法证实了前一年春季正是与华北汛期降水相关最显著的时段;而所选关键区正是处于一种范围更大的100 hPa高度场空间分布型的关键部位,而华北地区是关键区影响中国东部降水的最显著的区域之一.  相似文献