用我国地磁资料对磁层大尺度扰动之赤道电急流效应的初步分析   总被引：2，自引：0，他引：2       下载免费PDF全文

资民筠  高玉芬  沈长寿 《地球物理学报》1988,31(3):257-269

本文利用我国琼中、广州、泉州三站1982-1983年地磁Z分量资料,对磁暴主相发展及恢复相初期的赤道电急流变化进行了研究。形态分析、周期叠加和相关分析均表明,不论在何地方时,对应环电流的发展有△Z的负扰（附加东向电急流）;而D_st开始回升则有△Z的正扰（附加西向电急流）。该变化之大小可能受地方时的调制。方差分析、x²-分析等统计检验也认证了上述变化。文中还对△Z正、负扰与极区电急流及极尖区位置的高、低纬向移动进行了讨论。本文结果表明,分析扰日赤道电急流变化应区分磁暴的不同阶段,即区分电动耦合和动力耦合效应。今后应采用大范围台站网资料,进一步得出有关电流系的图象。  相似文献   

冬季赤道中东太平洋区域海表温度异常对北太平洋风暴轴年际变化的影响   总被引：8，自引：0，他引：8  

朱伟军  孙照渤  闵锦忠  彭加毅 《热带气象学报》2000,16(1):91-96

对１５个冬季北太平洋风暴轴区域５００ｈＰａ天气尺度滤波位势高度方差与同期热带太平洋海表温度进行了奇异值分解（ＳＶＤ）分析,结果表明,ＳＶＤ得到的第一对空间典型分布反映了赤道中、东太平洋区域海温异常对风暴轴变化的影响。进一步的合成分析显示,赤道中、东太平洋区域海表温度异常可以通过激发或加强５００ｈＰａ高度场上的ＰＮＡ遥相关型,主要影响冬季北太平洋风暴轴的东西摆动及其中、东端的强度变化。  相似文献   

Assessment of Impact of Storm on Point Source Pollutant Transport in Estuary by Dissolved Tracer Modeling     

Wanga  Ping  Linker  Lewis  Batiuk  Richard  Shenk  Gary 《Water Quality and Ecosystems Modeling》2000,1(1-4):253-269

A continuously discharged dissolved conservative tracer was simulated with the Chesapeake Bay Estuary Model Package to study pollutant transport in the estuary in response to point source loads and the impact of the November, 1985 storm. A visualization technology is applied to show 3-dimensional concentration variations in a continuous daily time sequence. The differential responses of daily net transport during storms versus inter-storm periods can be observed from an MPEG movie. It may take 2–3 months for a tracer to travel from the fall-line to the mouth of a river during relatively dry seasons, only 2 weeks in some medium storms, and less than 5 days in a big storm. Plots of daily concentrations from eleven selected locations in the estuary provide quantitative information on the response of tracer concentration to flows. The magnitude and time of tracer peaks related with different weather events in these locations reflect the combined effects of flows from various directions to these locations. The lower tributaries (which are closer to the Bay mouth) are affected more than the upper tributaries by a source discharged at a mid-tributary. A storm can transport materials more effectively to the Bay and affect adjacent tributaries more severely.  相似文献   

三亚市3月份突发性暴雨个例分析及预报     

吴士昌  黄萍 《气象研究与应用》2000,21(4):27-28

应用道尔顿蒸发公式的思路,在短期预报的基础上又对突发性暴雨进行中期预报尝试.  相似文献   

新疆典型区耕地资源卫星遥感调查分析   总被引：6，自引：0，他引：6  

乔木  马虹  杨发相  岳健  孙莉  张占君 《干旱区地理》2000,23(3):244-251

本文根据土地对农业生产的适宜程度,考虑到卫星遥感与地理信息系统相结合技术在耕地资源调查中的实际可操作性,划分耕地资源类型＾〔１￣３〕,并运用卫星遥感分析方法,对新疆典型地区耕地资源进行调查研究,搞清新疆典型地区耕地资源类型特征、分布规律,进而探索该区耕地资源区域开发与中低产田分区治理的方法理论与措施。  相似文献   

滇中中元古代昆阳群因民组碎屑风暴岩及其意义   总被引：16，自引：1，他引：15  

杜远生  韩欣 《沉积学报》2000,18(2):259-261

滇中地区中元古代昆阳群因民组以碎屑岩为主,内发育典型的风暴沉积构造 (包括渠铸型、丘状交错层理和洼状交错层理、递变层理等 )。风暴沉积主要包括 4种岩相类型 :A -具口袋构造的递变层理砂岩段。B -具丘状或洼状交错层理的砂岩段。C -具均质层理的粉砂岩、泥质岩段。D -具水平层理的泥质岩段。上述岩相A、B、C分别代表风暴流作用 -风暴浪作用 -风暴后期的快速悬浮沉积 (事件沉积 ),D代表风暴过后缓慢悬浮沉积 (背景沉积 ),它们组合成不同的风暴沉积序列。滇中地区昆阳群风暴沉积的发现表明中元古代大气圈、水圈及其相互作用与现今近似;中元古代滇中地区位于低纬度 (5 - 30°)的风暴作用带。该沉积对于解释因民组递变层砂岩的成因、证实昆阳群的地层层序也具有重要意义。  相似文献   

兰州风尘沉积的粒度分布模式及其古气候意义   总被引：21，自引：5，他引：16  

戴雪荣  李吉均  俞立中  师育新  王家澄 《沉积学报》2000,18(1):36-42

通过对兰州不同气候背景下形成的风尘沉积 1 80个样品详细的粒度分析,建立了该地区风尘沉积的粒度分布基本模式。发现研究区风尘沉积具有以下特征:(1 )沉积物分选差,主要由粒径 >4Φ的颗粒组成,平均6.4Φ (2 )粒级构成为极细砂 2.6 %、粉砂 77.8%、粘土 1 9.6 %,属粉质重亚粘土或典型黄土 (3)频率曲线为单峰、极正偏类型,且具有粗头短促、中间宽大和细尾拉长的特点 (4)短期悬浮颗粒与长期悬浮颗粒大致呈对等配比。这些特征同时也为兰州现代尘暴沉积物所具备,因而可视为该地区风尘沉积的一个基本诊断模式搬运方式。颗粒粒径 <5.5 0Φ的含量指标 (GSP1)和 4.5 0～ 6.5 0Φ的含量指标 (GSP2 )可分别作为冰期-间冰期尺度和冰段-间冰段尺度东亚冬季风演化和沙尘暴强弱程度的基本判据。  相似文献   

Factors Influencing the Incorporation of Hazard Mitigation During Recovery from Disaster     

Swaroop D. Reddy 《Natural Hazards》2000,22(2):185-201

This paper examines the factors promoting theadoption of mitigation measures during long-term recoveryfollowing Hurricane Hugo in the United States. Recovery fromdisaster offers opportunities for improving community resilienceto future disasters and for promoting sustainability. Variousdynamics during recovery, however, can interfere with mitigationof hazards. In this study the adoption of mitigation duringrecovery in three case communities after Hurricane Hugo isevaluated, with a focus on the influence of various regulations onhazard mitigation. There is a very strong connection betweendevelopment management and hazard mitigation; resourcemanagement also contributes to hazard mitigation. Conditionsthat influence advancement of hazard mitigation at thecommunity level include local leadership, a linkage betweenwell-established ways of doing things and new policies,adaptation to dynamic local conditions, monitoring andcompliance strategies tailored to suit local conditions, recognitionof local rights, and stakeholders' involvement in developingstrategies.  相似文献   

Python在CINRAD风暴数据可视化中的应用     

何佳  惠建忠  王曙东  洪晓媛  王阔音 《气象科技》2020,48(3):374-379

利用Python语言实现了新一代多普勒天气雷达风暴数据的解码和可视化。通过建立风暴自动匹配方法,利用Python地理信息可视化和时间序列可视化技术,实现风暴追踪的动画显示效果;利用Python数据分析与图表可视化技术,实现风暴多维度信息的图表显示,直观展示风暴变化趋势。本文提供了一种更加通用的快速获取风暴信息的方法,为气象业务工作者使用雷达资料带来便利。同时,增强的风暴信息可视化效果提高了资料再利用价值,为专业领域的研究提供支持。  相似文献   

Different Summer Rainfall Anomaly Patterns in Northeast China Associated with Two Kinds of El Niño Events     

王钦  李双林 《热带气象学报(英文版)》2020,26(2):223-230

The relationship between summer rainfall anomalies in northeast China and two types of El Ni?o events is investigated by using observation data and an AGCM. It is shown that, for different types of El Ni?o events, there is different rainfall anomaly pattern in the following summer. In the following year of a typical El Ni?o event, there are remarkable positive rainfall anomalies in the central-western region of northeast China, whereas the pattern of more rainfall in the south end and less rainfall in the north end of northeast China easily appears in an El Ni?o Modoki event. The reason for the distinct differences is that, associated with the different sea surface temperature anomalies (SSTA) along the equatorial Pacific, the large-scale circulation anomalies along east coast of East Asia shift northward in the following summer of El Ni?o Modoki events. Influenced by the anomalous anticyclone in Philippine Sea, southwesterly anomalies over eastern China strengthens summer monsoon and bring more water vapor to Northeast China. Meanwhile, convergence and updraft is strengthened by the anomalous cyclone right in Northeast China in typical El Ni?o events. These moisture and atmospheric circulation conditions are favorable for enhanced precipitation. However, because of the northward shift, the anomalous anticyclone which is in Philippine Sea in typical El Ni?o cases shifts to the south of Japan in Modoki years, and the anomalous cyclone which is in the Northeast China in typical El Ni?o cases shifts to the north of Northeast China, leading to the “dipole pattern” of rainfall anomalies. According to the results of numerical experiments, we further conform that the tropical SSTA in different types of El Ni?o event can give rise to observed rainfall anomaly patterns in Northeast China.  相似文献