两类El Niňo事件次年夏季长江-黄河流域降水低频特征及低频水汽输送途径差异          下载免费PDF全文

李丽平  倪语蔓  杨春艳  马晨誉 《大气科学学报》2019,42(3):420-433

利用1961年1月—2014年12月Hadley气候预测研究中心的全球海表温度(SST)资料,NECP/NCAR逐日风场、比湿等再分析资料,国家气象信息中心提供的中国753站逐日降水、160站逐月降水资料,对比分析了东部(EP)型和中部(CP)型两类El Niňo事件次年夏季长江-黄河流域降水(简记为EP型和CP型降水)低频特征,以及与之相关的低频水汽输送差异。结果表明,1)平均而言,EP型降水主要有10～20 d(最显著)以及20～30 d(次显著)低频周期;CP型降水主要有10～20 d的低频显著周期。与之相关的纬、经向水汽通量最显著低频周期也为10～20 d。2)影响EP、CP型低频降水共同的低频水汽环流系统主要有:菲律宾群岛附近的异常反气旋式水汽环流和渤海湾附近(日本东南侧)的异常气旋式(反气旋式)水汽环流。另外,影响EP(CP)型低频降水的还有来自巴尔喀什湖东北部异常气旋式水汽环流(孟加拉湾、苏门答腊岛以西的异常气旋式水汽环流对和贝加尔湖西、东两侧的异常气旋式、反气旋式环流)。3)EP型降水暖湿水汽主要源自南海,冷湿水汽主要源自西北太平洋,冷空气来自巴尔喀什湖东北部和贝加尔湖西北侧。CP型降水暖湿水汽少量来自阿拉伯海和印度洋,大量来自热带西太平洋,冷空气主要来自贝加尔湖西北侧。  相似文献   

A framework for testing dynamic classification of vulnerable scenarios in ensemble water supply projections     

Robinson  Bethany  Herman  Jonathan D. 《Climatic change》2019,152(3-4):431-448

Climatic Change - Recent water resources planning studies have proposed climate adaptation strategies in which infrastructure and policy actions are triggered by observed thresholds or...  相似文献   

Effects of commercial timber harvesting on streamflow regimes in the Plynlimon catchments,mid‐Wales     

M. Robinson  A. Dupeyrat 《水文研究》2005,19(6):1213-1226

This paper presents the first large‐scale British study of the impacts of commercial forest cutting on stream‐flow regimes. The 70% forested headwaters of the River Severn are part of the intensively instrumented long‐term Plynlimon catchment study into the impact of land use on stream flow. The forest area, comprising predominantly Sitka spruce (Picea sitchensis), was planted mainly in the 1930s and 1940s. Harvesting commenced in the mid‐1980s and over the study period about half the forest has been felled. Changes in annual water yield and extreme flows were studied in four nested catchments ranging in area from about 1 to 10 km² and compared with an adjacent benchmark grassland catchment. As expected from earlier process studies the cutting of the forest increased total annual flows. Less expected was the clear evidence that the felling augmented low flows. This informs a long‐standing debate whether upland forestry increases or reduces baseflows. A particularly notable result was the lack of impact of the harvesting on storm peak flows. This may result from the application of forest management guidelines designed to reduce soil damage and erosion during the harvesting, and indicates that the forest itself has a limited impact on flooding. These findings are timely because British forest expansion peaked in the 30 years following the Second World War, and large areas of these woodlands are now approaching economic maturity and will be harvested in the next two decades. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

On the theory of thin rotating jets: A quasi‐geostrophic time dependent model     

A. R. Robinson  J. R. Luyten  G. Flierl 《地球物理与天体物理流体动力学》2013,107(3):211-244

The time‐dependent meandering in a thin baroclinic jet over bottom topography is discussed in the quasi‐geostrophic approximation. The motion of the axis of the jet is taken to be vertically coherent and the axis itself is defined as inextensible. The motion is examined from a frame of reference moving with the axis but fixed at an arbitrary longitude in terms of an open ocean spatial initial value problem. The velocities of the axis and of the jet are quasi‐geostrophic, and vorticity conservation for the first non‐geostrophic components constrains the evolution of the axis and gives a path equation. The spatial linearized stability problem is studied and the jet is found to be baroclinically unstable to path disturbances of sufficiently high frequency which amplify downstream. An exact solution is obtained to the nonlinear path equation over a flat bottom with no ß‐effect. The evolution of the path of these unstable meanders is such that the path closes itself and forms rings (at which point the analysis breaks down). It is proposed that the baroclinic jet processes studied here are fundamental to the dynamics of Gulf Stream meandering and isolated eddy production.  相似文献   

Preface     

Dale B. Haidvogel  Allan R. Robinson 《Dynamics of Atmospheres and Oceans》1989,13(3-4)

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Identifying Fracture Interconnections Between Boreholes Using Natural Temperature Profiling: I. Conceptual Basis   总被引：3，自引：0，他引：3  

S. Silliman  R. Robinson 《Ground water》1989,27(3):393-402

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Magnotospheric imaging of high latitude ion outflows     

D. E. Garrido  R. M. Robinson  Y. T. Chiu  H. L. Collin  R. W. Smith  D. W. Swift 《Annales Geophysicae》1994,12(2-3):169-182

High latitude ion outflows mostly consist of upward streaming O⁺ and He⁺ emanating from the ionosphere. At heights above 1000 km, these flows consist of cold and hot components which resonantly scatter solar extreme ultraviolet (EUV) light, however, the ion populations respond differently to Doppler shifting resulting from the large relative velocities between the ions and the Sun. The possibility of optical detection of the Doppler effect on the scattering rate will be discussed for the O⁺ (83.4 nm) ions. We have contrasted the EUV solar resonance images of these outflows by simulations of the 30.4 nm He⁺ and 83.4 nm O⁺ emissions for both quiet and disturbed geomagnetic conditions. Input data for the 1000 km level has been obtained from the EICS instrument aboard the Dynamics Explorer satellite. Our results show emission rates of 50 and 56 milli-Rayleighs at 30.4 nm for quiet and disturbed conditions and 65 and 75 milli-Rayleighs at 83.4 nm for quiet and disturbed conditions, respectively, obtained for a polar orbiting satellite and viewing radially outward. We also find that an imager at an equatorial distance of 9 R_E or more is in a favorable position for detecting ion outflows, particularly when the plasmapause is depressed in latitude. However, an occultation disk is necessary to obscure the bright plasmaspheric emissions.  相似文献   

Comparisons of modelled and observed climate for impact assessments     

P. J. Robinson  A. N. Samel  G. Madden 《Theoretical and Applied Climatology》1993,48(2-3):75-87

Summary Comparisons between observed and modelled values of surface temperature, surface precipitation and 500 hPa height for the current climate were made for the southeast United States. Daily values and analyses pertinent to impact assessment, were emphasized. For the model, the time-independent 10-year series of values developed by the Geophysical Fluid Dynamics Laboratory general circulation model were used. Observations were drawn from records for various stations and decades within the model grid-cell. Cumulative frequency distributions of temperature indicated both more clustering close to the mean and greater extremes for the model. The model reproduced the seasonal cycle of day-to-day temperature variability, but introduced a phase shift of about four months. One result was an apparent overabundance of hot spells in the model results. For precipitation the model indicated twice as many raindays as were observed, about the same number of days when precipitation exceeded 5 mm, and fewer days with amounts exceeding 10 mm, effectively decreasing the probability of heavy precipitation while enhancing annual totals. In winter the model appeared to represent the results from an aggregation of stations within the grid-cell, but in summer it was closer to individual station results. The model reproduced the seasonal cycle in the height and standard deviation of the 500 hPa surface, with a damped amplitude in both cases.With 9 Figures  相似文献   

A Laboratory and Numerical Investigation of Solute Transport in Discontinuous Fracture Systems   总被引：2，自引：0，他引：2  

J. W. Robinson  J. E. Gale 《Ground water》1990,28(1):25-36

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华北强震断层面解和震源深度特征   总被引：17，自引：1，他引：17       下载免费PDF全文

汪素云 Ni  J 《地球物理学报》1991,34(1):42-54

本文利用远震P波及SH波和区域地震P_(nl)波波形反演方法,测定了华北9次强震的断层面解、震源深度及地震矩.结合其他作者测定的7次地震的结果,分析了华北16次强震断层面解及华北地震震源深度特征.结果表明,华北多数强震为走滑型地震,也有个别正断层型及逆断层型地震;16次地震多数发生在地壳中部10-25km深度范围内.  相似文献