THE ROLE OF THE MERIDIONAL CIRCULATION IN STATIONARY WAVE PROPAGATION     

Song Yan  Miao Jinhai 《Acta Meteorologica Sinica》1996,10(4):453-462

In a general baroclinic atmosphere,when the basic state includes meridional circulation,the sta-tionary waves might not only pass through the equatorial easterlies,but also strengthen significantly.The orographic forcing in the Northern Hemisphere mid-latitude might cause marked responses in thelow latitude atmosphere.This suggests that the meridional circulation plays an important role in theconnection of stationary responses in mid and low latitudes,and so does the heating forcing in theNorthern Hemisphere mid-latitude.Forced by the heating forcing in the Northern Hemisphere mid-latitude,the features similar to the Northern Hemisphere summer monsoon circulation can be ob-tained.It appears that the meridional circulation plays certain role in the formation of summer mon-soon circulation.The heating anomaly forcing located at the eastern equatorial Pacific makes the sta-tionary waves present PNA(Pacific-North America)pattern in the winter hemisphere,but it doesnot in the summer hemisphere.It suggests that the meridional circulation has a marked influence onthe route of stationary wave propagation both in the winter and summer hemispheres.  相似文献   

云南省40年来气温场变化的基本特征   总被引：1，自引：1，他引：1  

王宇  缪启龙 《南京气象学院学报》1996,19(4):478-481

根据云南省内分布相对均匀，资料年代较长的１８个代表站的１９５１－１９９４４上气温资料，用ＥＯＦ方法分析了４０年来云南省气温场变化的基本特征。  相似文献   

Sources and paleoclimatic significance of Holocene Bignell Loess, central Great Plains, USA     

Joseph A. Mason  Peter M. Jacobs  Paul R. Hanson  Xiaodong Miao  Ronald J. Goble 《Quaternary Research》2003,60(3):330-339

This paper reexamines the stratigraphy, sources, and paleoclimatic significance of Holocene Bignell Loess in the central Great Plains. A broadly similar sequence of loess depositional units and paleosols was observed in thick Bignell Loess sections up to 300 km apart, suggesting that these sections record major regional changes in the balance between dust deposition and pedogenesis. New optical ages, together with previously reported radiocarbon ages, indicate Bignell Loess deposition began 9000–11,000 yr ago and continued into the late Holocene; some Bignell Loess is <1000 yr old. There is little evidence that Holocene Loess was derived from flood plain sources, as previously proposed. Instead, thick Bignell Loess occurs mainly near the downwind margins of inactive dune fields, particularly atop escarpments facing the dunes. Thus, the immediate loess source was dust produced when the dunes were active. Previous work indicates that widespread episodes of dune activity are likely to have resulted from drier-than-present climatic conditions. The regionally coherent stratigraphy of Bignell Loess can be interpreted as a near-continuous record of climatically driven variation in dune field activity throughout the Holocene.  相似文献   

Normal reference value of hemoglobin of young women and geographical factors in China     

GE Miao 《地理学报》2003,13(3):331-338

A research is conducted on the relationship between the normal reference value of 20,475 examples of hemoglobin of young women and five geographical factors in 208 areas in China, the normal reference value is determined by the hemoglobincyanide method. It is found that the correlation of geographical factors and the normal reference value of hemoglobin of young women are quite significant (F=142.81). By using the method of multiple linear regression analysis, one regression equation is inferred. If geographical values are obtained in some areas, the normal reference value of hemoglobin of young women of this area can be reckoned by using the regression equation. Furthermore, depending on the geographical factors, China can be divided into six regions: Qinghai-Tibet (Qingzang) Plateau, Southwest, Northwest, Southeast, North and Northeast China.  相似文献   

对流边界层大涡模式的改进及对夹卷速度的研究   总被引：9，自引：0，他引：9  

苗世光  蒋维楣  李昕  刘衡 《大气科学》2001,25(1):25-37

对已建的对流边界层(CBL)大涡模式进行了改进，将次网格闭合方案改为次网格能量闭合，并考虑了水汽的源汇项和水汽相变潜热的作用。通过对均匀下垫面上由热扰动发展的对流边界层的模拟及与实验结果的比较表明，模式较好地模拟了对流边界层的主要物理结构，较好地反映了各物理量之间的对应关系。本文在一定的对流理查森数(Ri*)范围内给出了一些算例，对无量纲夹卷速度(We/W*)进行了研究。结果表明，无量纲夹卷速度随地表热通量(Qs)的增大而增大，随对流边界层上部温度递减率（γ)的增大而减小。当9.06≤Ri*≤45.29时，无量纲夹卷速度We/W*可以拟合成A(Ri*)-1的形式，其中A=0.226。并且与我们的对流槽实验结果，Sullivan等人的大涡模拟结果以及Deardorff等人的对流槽实验结果作了比较，四者吻合较好。  相似文献   

南极格罗夫山陨石岩石学特征Ⅱ:平衡型普通球粒陨石   总被引：5，自引：0，他引：5       下载免费PDF全文

缪秉魁  林杨挺  欧阳自远  周新华 《极地研究》2002,14(4):288-299

我国第16次南极科考队回收的28块陨石中,除1块火星陨石、1块HED陨石和6块非平衡L3型陨石外,其余20块为平衡型普通球粒陨石。根据橄榄石的平均Fa值、低Ca辉石的平均Fs值和Fe-Ni金属含量将这20块陨石分别划分为H、L和LL等化学群;根据球粒结构、基质重结晶程度和矿物成分对这些陨石进行岩石类型的划分。由于平衡型普通球粒陨石已达热力学平衡,橄榄石和低Ca辉石的成分相当均一,并且平均Fa和Fs值均与陨石的含Fe总量呈很好的反比关系,因此橄榄石平均Fa值和低钙辉石平均Fs值是平衡型陨石重要的化学群分类标准。20块平衡型普通球粒陨石的化学-岩石类型为:6个H群(3个H4、1个H5和2个H6)、9个L群(3个L4、1个L5和5个L6)和5个LL群(2个LL4、3个LL5)。  相似文献   

Estimation of the potential supply of U.S. oil by life cycle and learning models     

DeVerle Harris  Ying Hong Miao  Guocheng Pan  Tetevi Wilson 《Natural Resources Research》1992,1(3):239-252

Two methods of estimating potential U.S. oil supply are reported: life cycle analysis of updated (1987) oil production data, and an analysis based on learning curve modeling of discovery rates. Based on these analyses, potential U.S. (lower 48 plus Alaska) oil supply (ultimate recoverable oil) is estimated to be 222 billion barrels. A rough inference of the economic reference for this potential oil supply is an oil price of about $20/bbl (1989 dollars).  相似文献   

江宁台井下地电阻率变化初步分析     

樊晓春  李伟  鲍海英  董淼  吴帆  袁慎杰 《中国地震》2020,36(3):594-606

江宁台附近地铁可能对地电阻率观测的干扰较大，通过提取江宁台井下地电阻率夜间数据来分析其变化并探讨机理。结果表明：①江宁台井下地电阻率具备一定地表浅层抑制干扰能力，主要干扰源为地铁；②夜间1~3时数据突跳与地铁不定期维护有关；③井下地电阻率观测NS（AB=1000m）和NS（AB=200m）2018年10月开始出现快速下降变化后，江宁台周围地震强度明显增强，认为该变化与S340公路金属护栏无关；④井下地电阻率长趋势下降变化与周围深井水位变化一致，反映了周围区域应力调整的变化；⑤井下地电阻率观测EW（AB=200m）在安徽无为M_L 4.1地震前出现的"U"型变化与新建S340公路无关；⑥江宁台井下地电阻率共观测到5次"U"型变化，认为与地震有关的可能性较大。  相似文献   

分支河流体系在东海西湖凹陷南部的运用及其对油气潜力的指示          下载免费PDF全文

何苗  秦兰芝  尹太举  刘勇  王建宁  冯文杰 《中国地质》2021,48(3):820-831

本文以西湖凹陷南部地区为例,首次将分支河流体系(Distributive Fluvial System)研究思路应用到东海盆地沉积体系的研究中来。通过总结大型分支河流体系形成条件,与国外案例类比认为西湖凹陷南部近物源,构造稳定,存在大型盆山体系,具备发育大型分支河流体系条件;在此基础上根据花港组岩心、古生物特征对分支河道类型进行了划分,认为分支河道类型以陆上环境下的分汊状辫状河道和单辫状河道为主,不同类型的河道均具备发育厚层砂体的潜能;结合古地形和沉积体系平面特征,对分支河流体系展布模式的研究结果表明,区域花港组时期发育两套分支河流体系,展布型式为自西斜坡分别至东北、东南向发散,分支河流体系末梢属于"轴向终止"型,且西湖凹陷轴向限制型河流与南部"分支河流体系"汇聚地带具有油气藏勘探潜力。  相似文献   

地理国情监测系列地方标准研究与应用     

王淼  郭燕宾  杨旭东  秦飞  余永欣 《北京测绘》2021,35(5):607-610

标准是经济社会发展的技术支撑,也是国家质量技术基础建设的重要内容.项目依托第一次地理国情普查和北京市地理国情常态化监测工作,编制适合北京市具体特点的地理国情监测内容与指标、内业采集、外业调查、调绘底图制作、质量检查和统计分析等系列标准,并在数据建模理论与方法、城市监测技术体系、统计分析单元与计算方法、产品体系和应用模式等方面进行了创新,保证其实用性、针对性、先进性和可操作性,对地理国情监测的开展具有指导和促进作用.  相似文献