豫中南一次秋季区域性暴雨成因分析

利用常规观测资料、加密自动站资料、NCEP 1°×1°分析资料、FY-2E卫星及雷达资料等,采用诊断分析和对比分析方法,分析了2014年9月27—28日豫中南区域性暴雨的环流形势、强降水成因、中尺度特征及该过程与夏季暴雨的异同。结果表明:本次秋季暴雨过程是高空低槽、副高、中低层切变线、高低空急流、地面倒槽等系统共同作用的结果。持续的水汽辐合为暴雨提供了充沛的水汽条件,水汽通量大值区与水汽辐合中心分布及暴雨落区吻合;低层涡度的发展和水平风的切变导致垂直涡度发展,动力条件较好;K指数高值区对预报暴雨尤其强降水落区有较好指示意义,暴雨中心上空θse值随高度递减,高层低能舌叠加在低层高能区之上,强降水落区位于二者交汇的区域。低层偏东气流与高空槽前西南气流配合产生经向次级环流,上升运动增强;200 h Pa西风急流稳定维持,导致高层抽吸作用明显,有利于区域性暴雨发展。降水云团tbb一般在-32℃左右,发展高度明显低于夏季暴雨云团;降水前期回波为层云回波,后期转变为混合性回波,强降水主要由混合降水回波中的强对流云团导致的。中高层没有明显强冷空气,低层冷空气作用较大,东路冷空气一方面形成冷垫造成动力抬升,另一方面在低层与暖湿气流形成强水汽辐合,是本次秋季区域性暴雨的形成机制,也是不同于夏季暴雨的主要特征。     

陕西商南两岔口组牙形刺化石的发现

首次报道了东秦岭造山带奥陶系两岔口组中的牙形刺化石９个属。其组合面貌具有中奥陶世晚期牙形刺的特色,总体可与河南荆关一带寺岗组和陕西耀县一带桃启坡组中的牙形刺对比。     

Natural organics as fluorescent tracers of river-sea mixing

The use of dissolved organic matter fluorescence as a tracer of river-sea mixing was examined in two South Carolina estuaries. Fluorescence declined linearly with seawater dilution in laboratory mixing studies, and also behaved conservatively in an estuary where a single river emptied into a bay. Fluorescence-salinity relationships were also studied in another estuary where a piedmont river (high suspended sediment, low fluorescence) and a coastal plains river (low sediment, high fluorescence) mixed with ocean water. The factor of 2 or greater difference in fluorescence between the two rivers allowed their relative contribution to the estuarine water mass to be distinguished. Petroleum hydrocarbons, measured in estuarine water at 0·7-1·8 μg l⁻¹ concentrations, contributed negligibly to water fluorescence.     

厄尔尼诺事件与广州降水

分析了１９１０—１９９３年的厄尔尼诺事件与广州降水的关系。结果表明，在中、强厄尔尼诺当年，广州雨水偏多；在弱厄尔尼诺当年，广州雨水偏少并严重干旱。     

Statistical analysis of the distribution of fish eggs and larvae on the southeastern U.S. continental shelf with comments on oceanographic processes that may affect larval survival

Data collected in 1953 and 1954 by the U.S. Fish and Wildlife Service were statistically analyzed to ascertain where and when fish eggs and larvae are most abundant on the southeastern U.S. continental shelf. The results are related to some oceanographic processes that might affect the survival of larval fish. Along-shelf differences in numbers of eggs and larvae are minimal compared with differences that occur across the shelf. Highest numbers of fish larvae are found on the outer shelf during fall, winter and spring, but larvae are evenly distributed across the shelf in summer.Upwelling strongly influences the dynamics of plankton production on the outer shelf, and thus during most seasons of the year upwelling may be the most important process controlling the amount of food available to larval fish. During winter and spring, mean winds do not favor shoreward transport of larval fish from the outer shelf if the larvae are located in near-surface waters. Thus, during these seasons variability of winds on the ‘event’ time scale may be more important to onshore and offshore transport of larval fish than the mean strength and direction of monthly or seasonally averaged winds.     

Heat content change in the surface isothermal layer of a warm core ring in the sea east of Japan

Heat content change in the surface isothermal layer of a typical warm core ring in the sea east of Japan is described based on approximately 90 CTD profiles obtained by one profiling float. Erosion of the seasonal thermocline and development of a surface isothermal layer from the mid-summer to the early winter of 1999 are clearly seen. While heat content change between two consecutive profiles with a 35-hour time interval is much noisier, its 10-day running mean is consistent with net surface heat flux, indicating that surface heat flux dominates the temporal heat content change in the surface isothermal layer in the warm core ring.     

广西五圩箭猪坡铅锌锑矿床“西脉东层”找矿潜力分析

前人认为箭猪坡矿床是以铅锌锑为主的多金属热液型脉状矿床。本文通过与丹池成矿带上类似典型矿床的成矿地质条件的对比研究以及物探解译,认为箭猪坡矿床具有"西脉东层"的矿体空间产出模式,矿床东侧中深部具有找似层状、层状矿体的潜力。     

东亚夏季风降水中30—60天低频振荡

通过对东亚夏季风区域30年候降水量的分析研究可以看到,降水中30—60天低频振荡的季节变化与总的季风降水的季节变化具有明显的锁相关系,对季风雨带位置的出现起着重要的调制作用;降水低频振荡的年际变化对梅雨的年际变化也起着重要的调制作用;降水低频振荡呈现明显的由南向北的经向传播。     

东秦岭地区钼矿床中辉钼矿的铼含量及多型特征

辉钼矿是铼的最主要载体矿物。研究表明,东秦岭地区不同类型钼矿床中,辉钼矿的Re平均含量多为10—20ppm,其中仅黄龙铺碳酸岩脉型钼(铅)矿床的辉钼矿平均含Re高达152.5ppm。尽管辉钼矿中的铼含量有变化,但均呈类质同象取代钼而存在。同时,这些矿床辉钼矿的铼含量差异,主要取决于成矿热流体中原始铼含量。辉钼矿多型有2H型和2H+3R混合型。铼含量和成矿温度对辉钼矿多型没有影响,故辉钼矿多型对于钼矿床类型没有标型意义。     

基于CRA空间检验技术的西南地区东部强降水EC模式预报误差分析

CRA(contiguous rain area)空间检验技术是将连续雨区作为目标进行检验。通过设定降水量阈值,识别、分离及平移降水目标,将预报偏差分解为落区、强度和形态误差,该方法可避免传统TS评分的双惩罚效应。利用CRA空间检验技术对2011—2014年5—9月西南地区东部EC细网格模式36 h预报时效119个降水目标的预报误差进行分析,并按照环流形势和影响系统对强降水个例进行分型,分为西南地区东部低涡切变型、西南地区东部-江淮切变型、南风型,分别对上述三类不同类型强降水个例的落区和强度误差进行了对比。得到如下结论:西南地区东部降水预报形态误差占比最大,为60%左右,其次是落区误差,为30%左右,强度误差最小,约为10%;落区平均偏西0.7°,经向偏差不明显;模式对于水平尺度较小的降水目标漏报可能性较大,而对于天气尺度降水目标模式预报面积偏大,总降水量偏大,雨强偏小;西南地区东部低涡切变型和西南地区东部-江淮切变型降水强度预报误差类似,模式预报雨区面积均偏大,降水尺度越大,偏大的概率越大,实况平均降水强度越强,模式预报强度越偏弱;南风型预报强降水面积和平均强度均偏弱,出现漏报的概率较大;而对于最大降水量,三种类型模式预报的最强降水均较实况偏弱;西南地区东部低涡切变型模式预报落区偏西,江淮至西南地区东部切变型模式预报落区偏西偏北,南风型模式预报落区偏西偏南。