CHARACTERISTICS OF 10-DAY MEAN SURFACE SENSIBLE HEAT FLUX VARIATIONS IN THE SCS MONSOON REGION AND POSSIBLE CONNECTIONS WITH THE SCS SUMMER MONSOON ONSET^*     

Zhang Yaocun  Qian Yongfu 《Acta Meteorologica Sinica》1999,13(1):11-20

The time and space variations of the ten-day mean surface sensible heat flux have been analyzed in this paper based on the data of NCEP/NCAR from January of 1979 to December of 1995 in the South China Sea (SCS) monsoon region.It is found that large variations of the surface sensible heat flux standard deviations exist in the northwestern Indochina Peninsula and the Indian Peninsula regions,and their locations and strength change significantly during the onset period of SCS monsoon.The negative deviations appear evidently earlier in the Indocbina Peninsula than in the Indian Peninsula but the deviation strength in the Indian Peninsula is stronger than that in the Indochina Peninsula.The appearance of the zonal negative mean deviations in the southern part of the Indochina Peninsula corresponds to the date of the SCS summer monsoon onset,while the occurrence of the deviation decrease corresponds to the date of the South Asian monsoon onset.The sensible heat flux increases dekad by dekad before the onset of the summer monsoon in the Indian Peninsula and the Indochina Peninsula and decreases after the monsoon onset.Therefore,the surface sensible heat flux changes in the Indochina and the Indian Peninsula regions maybe have some connections with the SCS monsoon onset and the Indian monsoon onset,and the Indochina Peninsula maybe becomes the sensitive or key region to the SCS monsoon onset and the land maybe plays an important role in triggering summer monsoon onset.  相似文献   

CHARACTERISTICS OF 10-DAY MEAN SURFACE LATENT HEAT FLUX VARIATIONS IN THE SCS MONSOON REGION AND POSSIBLE CONNECTIONS WITH THE SCS SUMMER MONSOON ONSET   总被引：1，自引：0，他引：1  

张耀存  钱永甫 《Acta Meteorologica Sinica》1999,(4)

The temporal and spatial variations of the ten-day mean surface latent heat flux (TMLH) havebeen analyzed in this paper based on the data of NCEP from January of 1979 to December of 1995in the South China Sea (SCS) monsoon region. It is found that there exist maximum centers ofTMLH standard deviation in the northwest Indochina and the Indian Peninsula as well as thewestern Pacific, SCS, the Indian Ocean and the Bay of Bengal, and their locations and strengthschange significantly during the period of SCS monsoon onset. A positive zonal deviation of TMLHoccurs first in the Indochina Peninsula, apparently earlier than that in the Indian Peninsula. Theappearance of maximum positive zonal deviations of TMLH approximately coincides with thesummer monsoon onset. Over the Indochina and Indian Peninsulas, the TMLH increases graduallywith a small amplitude of variation before the onset of summer monsoon, and the rate of increase issignificantly enhanced after the onset of the monsoon; whereas over the ocean, TMLH decreasesbefore the monsoon onset, varies little during the period of monsoon and increases gradually afterthe ending of monsoon. Therefore, it seems that the surface latent heat flux plays an importantrole in the maintenance of the summer monsoon, and its variation is an phenomenon accompanyingthe onset of summer monsoon.  相似文献   

中国南方二叠纪层序地层时空格架及充填特征   总被引：9，自引：0，他引：9  

李祥辉  王成善 《沉积学报》1999,17(4):521-527

据华南二叠纪不同沉积盆地层序地层区域分布、纵向演化及其充填特征分析研究,初步建立了上扬子克拉通-右江盆地-钦防盆地、中扬子克拉通及全区的层序地层时空格架模型;提出层序充填可分为两个阶段:早二叠世碳酸盐缓坡-台地层序充填阶段,晚二叠世陆源碎屑为主与火山碎屑相混层序充填阶段;认为全区二叠纪四个Ⅰ型层序受控于构造隆升事件,晚二叠世层序TST普遍发育火山碎屑沉积,古陆边缘HST或少量SMT/LST大多由三角洲沉积体系进积叠加而成,上扬子克拉通及右江地区的生物礁以海侵和高位型为特色。  相似文献   

华南二叠纪层序地层与盆地演化   总被引：31，自引：2，他引：29  

陈洪德  王成善 《沉积学报》1999,17(4):528-535

新兴的层序地层学,是盆地分析的重要手段。华南二叠纪是华南板块海西-印支阶段盆地演化的重要时期,沉积盆地类型划分为克拉通盆地、板内及板缘伸展盆地,以及东吴运动后出现的前陆盆地和弧后盆地。南方二叠系由11个层序和1个半超层序组成,不同类型沉积盆地中层序地层具有不同的层序特征和充填形式。二叠纪是海西-印支期盆地演化由成熟到消亡的转折阶段,它们发育于扩张环境下,总体上是由两个克拉通盆地夹持一个伸展盆地。两个克拉通盆地的发展不均衡,中央伸展盆地沿着加里东的拼合带发育。这一古地理古构造格局与加里东期十分相似,由此认为,华南晚古生代沉积的构造背景,并不是稳定的克拉通环境。  相似文献   

Discontinuous Nature of the Lower Part of the South American Wadati-Benioff Zone in The Arica Elbow Region     

V. Hanuš  A. Slancová  A. Špiccaron;ák  J. Vaněk 《Studia Geophysica et Geodaetica》1999,43(2):163-184

The Arica Elbow region represents that part of Andean South America where the azimuth of the strike of the Peru-Chile trench changes from 150° to 190°. The area under study is roughly bounded by latitudes 17 °S and 23 °S, The shape of the Wadati-Benioff zone was studied in terms of the distribution of ISC hypocentres dated between 1964 and 1993. A system of 22 vertical cross-sections, perpendicular to the trench axis, and a map of epicentres was used to derive the detailed shape of the Wadati-Benioff zone of the presently descending slab. The distribution of earthquake foci indicates a fingerlike shape of the lower part of the Wadati-Benioff zone beneath the aseismic gap. The slab length shows small changes around 350 km in the northern sections, pronounced length oscillations between 350 and 750 km in the neighbouring central sections and a constant value of 650 km in the southern sections. The dip and thickness of the Wadati-Benioff zone are practically constant in all sections. Fault plane solutions, separated spatially into three zones, were used to estimate the state of stress in the slab.  相似文献   

近50 年华南地区极端强降水频次的时空变化特征   总被引：7，自引：2，他引：7  

陆虹  陈思蓉  郭媛  何慧  徐圣璇 《热带气象学报》2012,(2):219-227

利用华南地区110 个台站1961—2008 年逐日降水资料,采用百分位法定义各站极端强降水事件的阈值,运用线性回归、M-K 突变检验、正交函数分解(EOF)、旋转经验正交函数分解(REOF)等方法,对华南地区年极端强降水频次的时空变化特征进行分析。结果表明:在空间分布上,年极端强降水频次在华南中部较大、广东沿海和广西西部内陆较小;华南极端强降水频次有3 个主要的空间异常模态,一致性异常特征是华南极端强降水频次分布的最主要空间模态,而东、西反向和南、北反向变化模态也是比较重要的异常模态。在时间分布上,华南的极端强降水事件主要发生在夏半年,夏半年极端强降水频次占全年总频次的83.7%;1960 年代和1980 年代极端强降水频次较少,从1980 年代中后期起,极端强降水频次有由少变多的趋势。华南区域各站极端强降水频次气候倾向率不一致,除中部呈减少趋势外,其余大部呈上升趋势,华南区域各站极端强降水频次的平均序列也呈上升趋势,但上升趋势不显著。华南极端强降水频次从区域变化特征上可分为6 个主要区域,分别具有不同的年际变化趋势,其中有3 个区域的代表站先后发生了显著增多的突变现象。   相似文献   

温度,盐度和风应力对南海海流模拟的影响   总被引：1，自引：0，他引：1  

钱永甫  朱伯承 《南京气象学院学报》1999,22(1):26-31

用美国普林斯顿大学海洋模式（ＰＯＭ）对南中国海的年平均海流进行了数值模拟,对温盐结构和风应力在海流形成中的作用进行了较详细的讨论。结果表明,仅有温盐水平不均匀分布也可以驱动海水而生成南海海流,但此种海流的结构较乱,最大流速只有３０～４０ｃｍ·ｓ－１。若温盐无水平结构,则在风应力驱动下,南海海流的结构较为有序,且最大流速可增至６０～７０ｃｍ·ｓ－１。在温盐水平分布不均匀并有风应力的作用时,生成的南海海流与仅有风应力作用时的海流场较相似,说明在南海海流的形成中,风应力的作用更为重要。海面自由高度的分析也证明了上述结论。  相似文献   

Assessment of the potential for groundwater contamination using the DRASTIC/EGIS technique, Cheongju area, South Korea     

Youn Jong Kim  Se-Yeong Hamm 《Hydrogeology Journal》1999,7(2):227-235

  相似文献   

从岩相古地理论中国南方石炭系油气潜景   总被引：8，自引：4，他引：4       下载免费PDF全文

冯增昭  杨玉卿  金振奎  鲍志东 《古地理学报》1999,1(4):86-92

石炭系是中国南方重要的海相含油气地层之一。下石炭统的油气生成条件比上石炭统的好,这和早石炭世的盆地面积较大有关。石炭系下伏的志留系和上覆的二叠系的油气生成条件比石炭系还要好。上石炭统的油气储集条件比下石炭统的好,这和上石炭统的白云岩和滩相石灰岩分布较广有关。石炭系油气藏的直接盖层是下二叠统下部的梁山组,区域盖层是中新生代的泥岩为主的地层。南方石炭系油气生储盖条件的配置关系相当好。但是,南方石炭系以及整个古生代和三叠纪海相地层均经历了多次大的构造变动,其油气藏形成条件遭受相当大的破坏。在有利的生储配置关系的基础上,在区域盖层和保存条件较好的及面积较大的中新生代沉积盆地中,尤其是在邻近石炭系本身或其下伏志留系油气源岩的地区,是寻找和发现石炭系新的油气藏的有利地区。  相似文献   

贵州都匀下泥盆统蟒山群Zosterophyllum australianum(澳大利亚工蕨)新材料及其古地理意义^*          下载免费PDF全文

周志强  赵景宇  王嘉树  吴成洋  肖彪  黄璞 《古地理学报》1999,24(3):479-492

Zosterophyllum(工蕨属)是早期陆生植物的代表性类群之一,全球广泛分布。Z.australianum(澳大利亚工蕨)产自华南和澳大利亚,是东北冈瓦纳古植物地理区系的典型分子。文中描述了产自贵州都匀包阳剖面蟒山群中的Z.australianum新材料。该标本的孢子囊具短柄,呈椭圆形或扇形,宽2.6~4.1 mm,高可达3.9 mm,加厚带宽约0.6 mm,紧密螺旋排列形成孢子囊穗,与云南文山早泥盆世坡松冲植物群中的Z. australiaunum极为相似。依据目前对Z. australianum时代延限的认识,并结合蟒山群其他植物属种的发现(如Adoketophyton subverticillatum),推断该群下段的时代为早泥盆世布拉格期。Z. australianum在蟒山群中的发现,扩展了该植物的地理分布范围,反映出蟒山群中的植物组合与坡松冲植物群存在一定联系。  相似文献