Seasonal Forecasts of the Summer 2016 Yangtze River Basin Rainfall   总被引：1，自引：0，他引：1  

Philip E.BETT  Adam A.SCAIFE  Chaofan LI  Chris HEWITT  Nicola GOLDING  Peiqun ZHANG  Nick DUNSTONE  Doug M.SMITH  Hazel E.THORNTON  Riyu LU  Hong-Li REN 《大气科学进展》2018,35(8):918-926

The Yangtze River has been subject to heavy flooding throughout history,and in recent times severe floods such as those in 1998 have resulted in heavy loss of life and livelihoods.Dams along the river help to manage flood waters,and are important sources of electricity for the region.Being able to forecast high-impact events at long lead times therefore has enormous potential benefit.Recent improvements in seasonal forecasting mean that dynamical climate models can start to be used directly for operational services.The teleconnection from El Ni ?no to Yangtze River basin rainfall meant that the strong El Ni ?no in winter 2015/16 provided a valuable opportunity to test the application of a dynamical forecast system.This paper therefore presents a case study of a real-time seasonal forecast for the Yangtze River basin,building on previous work demonstrating the retrospective skill of such a forecast.A simple forecasting methodology is presented,in which the forecast probabilities are derived from the historical relationship between hindcast and observations.Its performance for2016 is discussed.The heavy rainfall in the May–June–July period was correctly forecast well in advance.August saw anomalously low rainfall,and the forecasts for the June–July–August period correctly showed closer to average levels.The forecasts contributed to the confidence of decision-makers across the Yangtze River basin.Trials of climate services such as this help to promote appropriate use of seasonal forecasts,and highlight areas for future improvements.  相似文献   

The Origin and Significance of Garnet Phenocrysts and Garnet-Bearing Xenoliths in Miocene Calc-alkaline Volcanics from Northland, New Zealand   总被引：2，自引：1，他引：1  

DAY  R. A.; GREEN  T. H.; SMITH  I.E.M. 《Journal of Petrology》1992,33(1):125-161

Xenoliths, considered to be of igneous origin and consistingof hornblendegarnetplagioclase clinopyroxene, occur in associationwith high-pressure phenocrysts in early Miocene high-silicaandesites and dacites, Northland, New Zealand. Microstructuresof these xenoliths range from coarse, even-grained sub-ophitictypes to others with coarse glomerocrysts set in a finer-grainedmesostasis. The xenoliths are commonly flow-banded and are arguedto represent direct crystallization products and crystal aggregationsfrom the calc-alkaline host or related magmas at depth. Manygarnets within these high-pressure aggregates and also discretegarnet phenocrysts are rimmed by medium—coarse-grained,interlocking hornblendeplagioclase, representing partial adjustmentto an assemblage stable at shallower levels. The garnets aretypically pyrope—almandine with 17–28 mol.% grossularand show normal, reverse and oscillatory zoning; the associatedamphibole is pargasite trending to hornblende in phenocrystrims and reaction rims. Metamorphic xenoliths with plagioclase-hornblende-quartzassemblages are also found in the rocks and are characterizedby fine-grained granoblastic mosaic microstructures with well-developedfoliation defined by preferred orientation of elongate grainsand a mineral layering. These metamorphic xenoliths are interpretedas fragments of lower-crustal country rocks accidentally incorporatedinto rising andesitic magma. Application of established experimental high-pressure phasediagrams for andesites indicates crystallization of these assemblagesat depths corresponding to 10–20-kb pressure, and appropriategeothermometers indicates the following temperatures for equilibrationof assemblages at a nominal pressure of 12 kb: garnet-augite980C; garnet-augite-hornblende 920–1020 C. Geobarometryon a single garnet—orthopyroxene-bearing xenolith indicatesa pressure of 10–12 kb for a likely temperature rangeof 950–1000C. Thus the xenoliths point to the generationof host andesite-dacite magmas at suberustal depths of 35–45km, from fractional crystallization of more mafic mantlederivedmagmas, and demonstrate that relatively silicic calc-alkalinemagmas may evolve in the mantle. The rarity of evidence forsuch a process may be linked with the obduction-related tectonicevents operative in Northland just before the magmatic episode,and to the unusually high water content in the magma.  相似文献   

BOUNDARY ELEMENT ANALYSIS OF LINEAR THERMOELASTIC CONSOLIDATION     

D. W. SMITH  J. R. BOOKER 《国际地质力学数值与分析法杂志》1996,20(7):457-488

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PUERTO PEÑASCO: FISHING VILLAGE TO TOURIST MECCA     

JOHN FINN  ARIANNA FERNANDEZ  LINDSEY SUTTON  DANIEL D. ARREOLA  CASEY D. ALLEN  CLAIRE SMITH 《Geographical review》2009,99(4):575-597

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COMMUNITY GARDENS AND POLITICS OF SCALE IN NEW YORK CITY*     

CHRISTOPHER M. SMITH  HILDA E. KURTZ 《Geographical review》2003,93(2):193-212

ABSTRACT. New York City community gardens have been the subject of political contestation over the course of their thirty‐year existence. In 1999, 114 gardens were slated for public auction and redevelopment. This article examines the controversy over the garden auction as a politics of scale in which garden advocates successively raised the scope of the controversy beyond the scale of individual gardens, and ultimately beyond that of the city. Analysis of this land‐use conflict highlights the significance of politics of scale for grassroots organizations within a market‐centric, neoliberal economic framework.  相似文献   

Continental drift,plateau uplift,and the evolutions of monsoon and arid regions in Asia,Africa, and Australia during the Cenozoic     

Xiaodong LIU  Buwen DONG  Zhi-Yong YIN  Robin S.SMITH  Qingchun GUO 《中国科学:地球科学(英文版)》2019,(7):1053-1075

Monsoon and arid regions in the Asia-Africa-Australia(A-A-A) realm occupy more than 60% of the total area of these continents. Geological evidence showed that significant changes occurred to the A-A-A environments of the monsoon and arid regions, the land-ocean configuration in the Eastern Hemisphere, and the topography of the Tibetan Plateau(TP) in the Cenozoic. Motivated by this background, numerical experiments for 5 typical geological periods during the Cenozoic were conducted using a coupled ocean-atmosphere general circulation model to systemically explore the formations and evolutionary histories of the Cenozoic A-A-A monsoon and arid regions under the influences of continental drift and plateau uplift. Results of the numerical experiments indicate that the timings and causes of the formations of monsoon and arid regions in the A-A-A realm were very different. The northern and southern African monsoons existed during the mid-Paleocene, while the South Asian monsoon appeared in the Eocene after the Indian Subcontinent moved into the tropical Northern Hemisphere. In contrast, the East Asian monsoon and northern Australian monsoon were established much later in the Miocene. The establishment of the tropical monsoons in northern and southern Africa, South Asia, and Australia were determined by both the continental drift and seasonal migration of the Inter-Tropical Convergence Zone(ITCZ), while the position and height of the TP were the key factor for the establishment of the East Asian monsoon. The presence of the subtropical arid regions in northern and southern Africa,Asia, and Australia depended on the positions of the continents and the control of the planetary scale subtropical high pressure zones, while the arid regions in the Arabian Peninsula and West Asia were closely related to the retreat of the Paratethys Sea. The formation of the mid-latitude arid region in the Asian interior, on the other hand, was the consequence of the uplift of the TP.These results from this study provide insight to the important roles played by the earth's tectonic boundary conditions in the formations and evolutions of regional climates during geological times.  相似文献   

Fluvial and submarine morphodynamics of laminar and near‐laminar flows: a synthesis     

ERIC LAJEUNESSE  LUCE MALVERTI  PIERRE LANCIEN  LAWRENCE ARMSTRONG  FRANCOIS MÉTIVIER  STEPHEN COLEMAN  CHARLES E. SMITH  TIMOTHY DAVIES  ALESSANDRO CANTELLI  GARY PARKER 《Sedimentology》2010,57(1):1-26

The interaction of flow with an erodible bed in alluvial rivers and deep‐sea channels gives rise to a wide range of self‐formed morphologies, including channels, ripples, dunes, antidunes, alternate bars, multiple‐row bars, meandering and braiding. As the flow is invariably turbulent in field manifestations of these morphologies, there has been a tendency to assume that turbulence is necessary for them to form. While turbulence undoubtedly has an important influence when it is present, it is not necessary for any of these features. Indeed, all of these features can be formed by the morphodynamic interaction of purely laminar or nearly laminar flow with an erodible bed. This paper provides a survey and synthesis of a wide range of laminar or near‐laminar flow analogues of morphologies observed in the field. Laminar‐flow analogues of turbulent‐flow morphologies cannot and should not be expected to satisfy dynamic similarity in terms of all relevant dimensionless parameters. What is of more significance is the convergence of the underlying physics. It is illustrated in this paper that many existing theoretical frameworks for the explanation of turbulent‐flow morphodynamics require only relatively minor modification in order to adapt them to laminar flows.  相似文献   

The Meteoritical Bulletin,No. 94, September 2008     

Michael K. WEISBERG  Caroline SMITH  Gretchen BENEDIX  Luigi FOLCO  Kevin RIGHTER  Jutta ZIPFEL  Akira YAMAGUCHI  Hasnaa CHENNAOUI AOUDJEHANE 《Meteoritics & planetary science》2008,43(9):1551-1584

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The detailed tephrostratigraphy of a core from the south‐east Black Sea spanning the last ∼60 ka          下载免费PDF全文

VICTORIA L. CULLEN  VICTORIA C. SMITH  HELGE W. ARZ 《第四纪科学杂志》2014,29(7):675-690

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Speleogenetic evidence from Ogof Draenen for a pre‐Devensian glaciation in the Brecon Beacons,South Wales,UK          下载免费PDF全文

ANDREW R. FARRANT  CHRISTOPHER J. M. SMITH  STEPHEN R. NOBLE  MICHAEL J. SIMMS  DAVID A. RICHARDS 《第四纪科学杂志》2014,29(8):815-826

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