Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere最新文献_第7页

Airborne observations of frontal systems in the inlet channel of the Ria de Aveiro, Portugal 葡萄牙Ria de Aveiro入口通道锋面系统的机载观测

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00075-2

J. Figueiredo da Silva , R.W. Duck , J.M. Anderson , J. McManus , J.G.C. Monk

{"title":"Airborne observations of frontal systems in the inlet channel of the Ria de Aveiro, Portugal","authors":"J. Figueiredo da Silva , R.W. Duck , J.M. Anderson , J. McManus , J.G.C. Monk","doi":"10.1016/S1464-1909(01)00075-2","DOIUrl":"https://doi.org/10.1016/S1464-1909(01)00075-2","url":null,"abstract":"<div><p>Flow from the Atlantic Ocean into the inlet channel of the Ria de Aveiro, Portugal, delimited by two west-converging breakwaters, moves a tidal prism of up to 110Mm<sup>3</sup>. The associated velocity field controls the formation and movement of foam lines and turbid water masses. Observation by airborne 35mm photography and direct measurements of surface water temperature, salinity and suspended solids concentration give a view of the circulation in the littoral zone, which is important as this area is soon to receive effluent from an outfall located c.3 km to the north. On the flood tide turbid water is diverted from the north-south direction of the littoral drift into the channel. On the ebb this turbid water is pushed offshore by a jet flowing west and south-west from the channel. The surface water temperature inside the channel mouth is lower on the north side where the salinity is less reduced by dilution with lagoon water. During the flood tide the water flowing from the north rotates to the east, forced by flow from the south-west along the axis of the channel. This motion holds the less dense water on the south side and causes intense vertical mixing on the N side. The frontal convergence of these two water masses is usually marked at the surface by a clear foam line.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 9","pages":"Pages 713-719"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00075-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137439724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Statistical atmospheric downscaling of short-term extreme rainfall by neural networks 短期极端降雨的神经网络统计大气降尺度

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00071-5

J. Olsson , C.B. Uvo , K. Jinno

{"title":"Statistical atmospheric downscaling of short-term extreme rainfall by neural networks","authors":"J. Olsson , C.B. Uvo , K. Jinno","doi":"10.1016/S1464-1909(01)00071-5","DOIUrl":"https://doi.org/10.1016/S1464-1909(01)00071-5","url":null,"abstract":"<div><p>Statistical atmospheric rainfall downscaling, that is, statistical estimation of local or regional rainfall on the basis of large-scale atmospheric circulation, has been advocated to make the output from global and regional climate models more accurate for a particular location or basin. Neural networks (NNs) have been used for such downscaling, but their application has proved problematic, mainly due to the numerous zero-values present in short-term rainfall time series. In the present study, using serially coupled NNs was tested as a way to improve performance. Mean 12-hour rainfall in the Chikugo River basin, Kyushu Island, Southern Japan, was downscaled from observations of precipitable water and zonal and meridional wind speed at 850 hPa, averaged over areas within which the temporal variation was found to be significantly correlated with basin rainfall. Basin rainfall was ranked into four categories: no-rain (0) and low (1), high (2) and extreme (3) intensity. A series of NN experiments showed that the best overall performance in terms of hit rates was achieved by a two-stage approach in which a first NN distinguished between no-rain (0) and rain (1–3), and a second NN distinguished between low, high, and extreme rainfalls. Using either a single NN to distinguish between all four categories or three NNs to successively detect extreme values proved inferior. The results demonstrate the need for an elaborate configuration when using NNs for short-term downscaling, and the importance of including physical considerations in the NN application.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 9","pages":"Pages 695-700"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00071-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137441671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Energy and water cycles over larger and medium-sized catchments 大中型集水区的能源和水循环

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00020-X

引用次数: 0

Hydrological and water quality modelling in a medium-sized coastal basin 中型沿海盆地的水文和水质模拟

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)85013-9

A. Francos , G. Bidoglio , L. Galbiati , F. Bouraoui , F.J. Elorza , S. Rekolainen , K. Manni , K. Granlund

引用次数: 43

Transport of impurities in 2D incompressible periodic flows 二维不可压缩周期流中杂质的输运

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00008-9

P. Paradisi , F. Tampieri

引用次数: 3

Rainfall-frequency mapping for Greece 希腊的降雨频率图

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00067-3

A. Loukas , L. Vasiliades , N.R. Dalezios , C. Domenikiotis

{"title":"Rainfall-frequency mapping for Greece","authors":"A. Loukas , L. Vasiliades , N.R. Dalezios , C. Domenikiotis","doi":"10.1016/S1464-1909(01)00067-3","DOIUrl":"10.1016/S1464-1909(01)00067-3","url":null,"abstract":"<div><p>For the design of hydrotechnical projects in ungauged watersheds, the flood flow is estimated by various methods, which demand the estimation of rainfall of particular critical duration and return period. For medium-sized and large basins, the storms causing flood flows have usually duration larger than 24 hours. In this study daily rainfall data from 24 meteorological stations for the period 1950 to 1981 were used. These stations are evenly distributed over Greece. From these data, the rainfall depths for various durations were computed, i.e. 1 to 7 days. The Extreme Value I (Gumbel) theoretical distribution had the best fit to the data from other theoretical distributions and it was fitted to the maximum annual rainfall depths for various durations. As a result, the Depth-Duration_Frequency relationships for each station were estimated and mapped for Greece. Moreover, the analysis showed that the rainfall of various durations and return periods represents a certain percentage of the mean annual precipitation for hydrologicaly homogeneous areas of Greece. The homogeneous areas were identified through factor analysis of monthly precipitation data from 37 meteorological stations. The results of this study can be used for the estimation of rainfall at ungauged sites in medium and large watersheds but they should be applied with caution in mountainous areas. For the estimation of rainfall in these areas the climatic conditions of the region and the orographic enhancement of rainfall should be considered.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 9","pages":"Pages 669-674"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00067-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87971435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

Comparison of atmospheric boundary layer soundings by a metric and a decimetric RASS 用公制和分制RASS探测大气边界层的比较

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(00)00240-9

P. Trivero , W. Biamino , A. Marzorati , P. Marcacci , G. Bonino , R. Rossello

{"title":"Comparison of atmospheric boundary layer soundings by a metric and a decimetric RASS","authors":"P. Trivero , W. Biamino , A. Marzorati , P. Marcacci , G. Bonino , R. Rossello","doi":"10.1016/S1464-1909(00)00240-9","DOIUrl":"10.1016/S1464-1909(00)00240-9","url":null,"abstract":"<div><p>The vertical thermal profile of the lower atmosphere can be remotely measured by the Radio Acoustic Sounding System (RASS). A RASS operating at the acoustic wavelength λ<sub>a</sub> ∼ 1 m was designed and developed twenty years ago. It is suitable for monitoring the temperature profile of the lower troposphere and has been utilised for studies of the atmospheric boundary layer in different conditions and for the application of control strategies to air pollution emissions. The acoustic antenna is composed by 9 folded horns covering an area of 7x7 m<sup>2</sup>; the two radar antennas are composed by arrays of dipoles with square reflector of 2.8x2.8 m<sup>2</sup> for each antenna. Therefore the metric RASS can be utilised only in a settled station. Recently we have designed and developed a decimetric RASS (λ<sub>a</sub> = 0.34 m) with smaller antennas, which can be used as a mobile system. It can be housed and carried by a trailer. As it is known, increasing the sounding frequency gives a decreasing of the sounding range. Comparisons of results obtained by both the metric and the decimetric RASS in different atmospheric conditions are presented and discussed.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 3","pages":"Pages 201-204"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(00)00240-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89119004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Towards integrated assessment of the implications of global change for water management - the Rhine experience 迈向综合评估全球变化对水管理的影响-莱茵河经验

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00049-1

H. Middelkoop , J.C.J. Kwadijk

{"title":"Towards integrated assessment of the implications of global change for water management - the Rhine experience","authors":"H. Middelkoop , J.C.J. Kwadijk","doi":"10.1016/S1464-1909(01)00049-1","DOIUrl":"https://doi.org/10.1016/S1464-1909(01)00049-1","url":null,"abstract":"<div><p>The rivers Rhine and Meuse fulfil important socio-economic and environmental functions for their riparian states. Even under present-day conditions, the demands for flood protection, inland navigation, ecology, hydropower, water availability for agriculture, industry and drinking water are high. Climate change is expected to enhance discrepancies between water supply and demand in the Rhine and Meuse rivers. This issue has been investigated in a sequence of climate-impact studies in the Rhine and Meuse basins. These studies firstly focused at hydrological changes. Subsequently, a detailed impact assessment of the demands and vulnerability of the user functions of the water systems in the Netherlands was carried out. In an ongoing project we will establish a set of integrated scenarios for the Rhine and Meuse basins, representing different world-views, based on the so-called Perspectives method. Using these scenarios we attempt to define water management strategies that are robust under uncertainty.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 7","pages":"Pages 553-560"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00049-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91635118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Validation of a regional weather forecast model with GPS data 利用GPS资料验证区域天气预报模式

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00028-4

K.-P. Johnsen, B. Rockel

{"title":"Validation of a regional weather forecast model with GPS data","authors":"K.-P. Johnsen, B. Rockel","doi":"10.1016/S1464-1909(01)00028-4","DOIUrl":"10.1016/S1464-1909(01)00028-4","url":null,"abstract":"<div><p>The atmospheric water vapor content is one of the most important parameters for the hydrological cycle. In order to investigate the energy and water balance over the Baltic Sea and its catchment, the hydrostatic regional weather forecast model HRM (<strong>H</strong>igh resolution <strong>R</strong>egional <strong>M</strong>odel) of the German Weather Service (DWD) is validated against groundbased GPS data within the BALTEX (Baltic Sea Experiment) region and the PIDCAP period (<strong>P</strong>ilot Study for <strong>I</strong>ntensive <strong>D</strong>ata <strong>C</strong>ollection and <strong>A</strong>nalysis of <strong>P</strong>recipitation; August 1 to November 17, 1995). The vertically integrated water vapor content (IWV) derived from HRM shows a high correlation (coefficient = 0.935) and slightly (≈ 2.69 kg/m<sup>2</sup>) greater mean values than the GPS data mainly due to greater mean analyses data.</p><p>Between 1995 and 1998 GPS/MET aboard the Micro-Lab 1 successfully demonstrated the radio occultation technique to probe the Earth's atmosphere through its refraction effects on the signals transmitted by the GPS satellites. Profiles of the water vapor can be obtained from the GPS derived refractivity by using the temperature profiles of the HRM model. For a comparison of the vertical distribution of the specific humidity these water vapor profiles are used. Also lower values than with HRM were found. A comparison of the vertically IWV as derived from GPS/MET and from HRM shows a high correlation (coefficient = 0.90).</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 5","pages":"Pages 415-419"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00028-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77250121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Intrusion of stratospheric ozone to the free troposphere through tropopause folds - a case study 平流层臭氧通过对流层顶褶皱侵入自由对流层-一个案例研究

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00088-0

J.H. Sørensen, N.W. Nielsen

{"title":"Intrusion of stratospheric ozone to the free troposphere through tropopause folds - a case study","authors":"J.H. Sørensen, N.W. Nielsen","doi":"10.1016/S1464-1909(01)00088-0","DOIUrl":"10.1016/S1464-1909(01)00088-0","url":null,"abstract":"<div><p>Simultaneous ozone radiosoundings at Jægersborg north of Copenhagen, Denmark, and at Gardermoen north of Oslo, Norway, at 12 UTC on 21 March, 1994, both show a pronounced peak of ozone in the free troposphere. A study involving routine radiosoundings as well as analysed numerical weather prediction (NWP) model data shows that a tropopause folding occurred over the Davis Strait and the southern part of Greenland about two days before the radiosoundings. Trajectory calculations performed using the same NWP model data indicate that air parcels corresponding to the observed ozone peaks at Jægersborg and at Gardermoen have passed trough the tropopause fold thus bringing down ozone rich air from the stratospheric ozone layer to the free troposphere. A quantitative simulation of this transport phenomenon is performed using an atmospheric three-dimensional long-range dispersion model. By fitting the simulated vertical profiles of ozone concentration to the observed profiles, an estimate is obtained of the rate of ozone intrusion through the tropopause fold.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 10","pages":"Pages 801-806"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00088-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80140721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22