全文获取类型
收费全文 | 78篇 |
免费 | 4篇 |
专业分类
测绘学 | 9篇 |
大气科学 | 24篇 |
地球物理 | 16篇 |
地质学 | 19篇 |
海洋学 | 1篇 |
天文学 | 4篇 |
自然地理 | 9篇 |
出版年
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 5篇 |
2012年 | 8篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有82条查询结果,搜索用时 468 毫秒
51.
Spatial uncertainty in bias corrected climate change projections and hydrogeological impacts
下载免费PDF全文
![点击此处可从《水文研究》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The question of which climate model bias correction methods and spatial scales for correction are optimal for both projecting future hydrological changes as well as removing initial model bias has so far received little attention. For 11 climate models (CMs), or GCM/RCM – Global/Regional Climate Model pairing, this paper analyses the relationship between complexity and robustness of three distribution‐based scaling (DBS) bias correction methods applied to daily precipitation at various spatial scales. Hydrological simulations are forced by CM inputs to assess the spatial uncertainty of groundwater head and stream discharge given the various DBS methods. A unique metric is devised, which allows for comparison of spatial variability in climate model bias and projected change in precipitation. It is found that the spatial variability in climate model bias is larger than in the climate change signals. The magnitude of spatial bias seen in precipitation inputs does not necessarily correspond to the magnitude of biases seen in hydrological outputs. Variables that integrate basin responses over time and space are more sensitive to mean spatial biases and less so on extremes. Hydrological simulations forced by the least parameterized DBS approach show the highest error in mean and maximum groundwater heads; however, the most highly parameterised DBS approach shows less robustness in future periods compared with the reference period it was trained in. For hydrological impacts studies, choice of bias correction method should depend on the spatial scale at which hydrological impacts variables are required and whether CM initial bias is spatially uniform or spatially varying. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
52.
Long-Term Profiles of Wind and Weibull Distribution Parameters up to 600 m in a Rural Coastal and an Inland Suburban Area 总被引:1,自引:1,他引:0
Sven-Erik Gryning Ekaterina Batchvarova Rogier Floors Alfredo Peña Burghard Brümmer Andrea N. Hahmann Torben Mikkelsen 《Boundary-Layer Meteorology》2014,150(2):167-184
An investigation of the long-term variability of wind profiles for wind energy applications is presented. The observations consists of wind measurements obtained from a ground-based wind lidar at heights between 100 and 600 m, in combination with measurements from tall meteorological towers at a flat rural coastal site in western Denmark and at an inland suburban area near Hamburg in Germany. Simulations with the weather research and forecasting numerical model were carried out in both forecast and analysis configurations. The scatter between measured and modelled wind speeds expressed by the root-mean-square error was about 10 % lower for the analysis compared to the forecast simulations. At the rural coastal site, the observed mean wind speeds above 60 m were underestimated by both the analysis and forecast model runs. For the inland suburban area, the mean wind speed is overestimated by both types of the simulations below 500 m. When studying the wind-speed variability with the Weibull distribution, the shape parameter was always underestimated by the forecast compared to both analysis simulations and measurements. At the rural coastal site although the measured and modelled Weibull distributions are different their variances are nearly the same. It is suggested to use the shape parameter for climatological mesoscale model evaluation. Based on the new measurements, a parametrization of the shape parameter for practical applications is suggested. 相似文献
53.
Oliver Krueger Frauke Feser Lars Bärring Eigil Kaas Torben Schmith Heikki Tuomenvirta Hans von Storch 《Climate Dynamics》2014,42(3-4):1127-1128
The main subject of this article is to comment on the issue of storminess trends derived from the twentieth century reanalysis (20CR) and from observations in the North Atlantic region written about in Wang et al. (Clim Dyn 40(11–12):2775–2800, 2012). The statement that the 20CR estimates would be consistent with storminess derived from pressure-based proxies does not hold for the time prior to 1950. 相似文献
54.
Ellen P. Bonnesen Flemming Larsen Torben O. Sonnenborg Kurt Klitten Lars Stemmerik 《Hydrogeology Journal》2009,17(7):1643-1663
High-concentration saltwaters occur in many places in the regional Chalk aquifers of North-West Europe; to investigate deep occurrences, profiles of interstitial porewater chemistry have been studied from three 250–450m deep cores drilled in the eastern parts of Zealand, Denmark. At the studied location, saline water in the Chalk resides at depths from 40 to 80m and salinity increases with depth. Concentrations of chloride up to ca. 30,000ppm have been observed at depths of 400m. Measured vertical hydraulic heads in open boreholes suggest that advective groundwater flow is now restricted in deeper parts of the Chalk formation and diffusive transport is thus the predominant transport mechanism. Laboratory-measured porosity and effective diffusion coefficients were used as input to a numerical 1D diffusion model of the interface between freshwater in an upper, fractured aquifer and modified connate formation water below. The model satisfactorily simulated the observed chloride and δ18O profiles. The diffusive refreshening of the Chalk formation has been going on for about 0.9 million years. The connate water in the Chalk of parts of the sedimentary basin seems to have been modified by transport of saltwater from underlying Mesozoic and Paleozoic sediments during compaction, which presumably ceased around 4 million years ago. 相似文献
55.
Andreas Sterl Richard Bintanja Laurent Brodeau Emily Gleeson Torben Koenigk Torben Schmith Tido Semmler Camiel Severijns Klaus Wyser Shuting Yang 《Climate Dynamics》2012,39(11):2631-2657
EC-Earth is a newly developed global climate system model. Its core components are the Integrated Forecast System (IFS) of the European Centre for Medium Range Weather Forecasts (ECMWF) as the atmosphere component and the Nucleus for European Modelling of the Ocean (NEMO) developed by Institute Pierre Simon Laplace (IPSL) as the ocean component. Both components are used with a horizontal resolution of roughly one degree. In this paper we describe the performance of NEMO in the coupled system by comparing model output with ocean observations. We concentrate on the surface ocean and mass transports. It appears that in general the model has a cold and fresh bias, but a much too warm Southern Ocean. While sea ice concentration and extent have realistic values, the ice tends to be too thick along the Siberian coast. Transports through important straits have realistic values, but generally are at the lower end of the range of observational estimates. Exceptions are very narrow straits (Gibraltar, Bering) which are too wide due to the limited resolution. Consequently the modelled transports through them are too high. The strength of the Atlantic meridional overturning circulation is also at the lower end of observational estimates. The interannual variability of key variables and correlations between them are realistic in size and pattern. This is especially true for the variability of surface temperature in the tropical Pacific (El Ni?o). Overall the ocean component of EC-Earth performs well and helps making EC-Earth a reliable climate model. 相似文献
56.
Torben Dall Schmidt 《GeoJournal》2005,64(3):249-258
Cross-border regional enlargement entails complex dynamics. The integration process at the maritime border between Sweden
and Denmark illustrates this. Physical infrastructure has been improved by national governments and intranational and supranational
institutions have added to the instrumentation as a precondition for social interaction and integration. The outcome of these
efforts is here tested under a hypothesis that in spite of this forceful cocktail of policy instruments, the cross-border
regionalization process is at best a long-run phenomenon in the ?resund Region. The point of departure is the stepwise procedure
for the formation of binational cities suggested in Ehlers (2001, GeoJournal
54: 21–32). Social interaction is identified as the pivotal factor in the present state of integration of the ?resund Region
using Bucken-Knapp (2001, GeoJournal
54: 51–60). A benchmarking method is proposed for testing social interaction in the labour market, where cross-border dynamics
are benchmarked against national dynamics. The cross-border regional enlargement process is still in its very infancy and
a continued focus on policies to promote cross-border social interaction is required. The present governance without government
approach to cross-border cooperation in the ?resund Region is in that respect challenged by a reform of the Danish geo-administrative
system. 相似文献
57.
Odleiv Olesen Mark A. Smethurst Trond H. Torsvik Torben Bidstrup 《Tectonophysics》2004,387(1-4):105-130
Gravity and magnetic anomalies have previously been interpreted to indicate strongly magnetic Permian or even Tertiary intrusive bodies beneath the Skagerrak waterway (such as the ‘Skagerrak volcano’) and beneath Silkeborg in Denmark. Our combined modelling of the magnetic and gravity anomalies over these rock bodies indicates that a steep upward magnetisation is required to explain the magnetic anomalies at the surface, reminiscent of the magnetic direction in the Sveconorwegian rocks of the Rogaland Igneous Province in southern Norway. The younger rocks of the Permian Oslo Rift region have intermediate and flat magnetisation that is inadequate to explain the observed magnetic field. The positive part of the Skagerrak aeromagnetic anomaly is continuous with the induced anomalies associated with the eastward extension of the Rogaland Igneous Province. This relation also suggests that rocks of the Rogaland Igneous Province and its offshore extension are responsible for the Skagerrak anomalies. Both the negative, remanence-dominated aeromagnetic anomaly and the positive gravity anomaly can be modelled using constraints from seismic reflection lines and available density data and rock-magnetic properties. A 7 km thick complex of ultramafic/mafic intrusions is located below a southward dipping 1–4 km thick section of Mesozoic sediments and 1–2 km of Palaeozoic sediments. The enormous body of dense, ultramafic/mafic rocks implied by the modelling could be the residue of the parental magma that produced the voluminous Rogaland anorthosites. The application of similar petrophysical properties in the forward modelling of the Silkeborg source body provides an improved explanation of the observed gravity and magnetic anomalies compared with earlier studies. The new model is constrained by magnetic depth estimates (from the Located Euler method) ranging between 6 and 8 km. Forward modelling shows that a model with a reverse magnetic body (anorthosite?) situated above a dense, mafic/ultramafic body may account for the Silkeborg anomalies. The anorthosites may have formed by differentiation of the underlying mafic intrusion, similar to the intrusive relations in the Rogaland Igneous Province. We conclude that there is strong evidence for a Sveconorwegian age for both the Skagerrak and the Silkeborg anomalous rock bodies. 相似文献
58.
59.
Torben Koenigk Mihaela Caian Grigory Nikulin Semjon Schimanke 《Climate Dynamics》2016,46(1-2):317-337
Seasonal prediction skill of winter mid and high northern latitudes climate from sea ice variations in eight different Arctic regions is analyzed using detrended ERA-interim data and satellite sea ice data for the period 1980–2013. We find significant correlations between ice areas in both September and November and winter sea level pressure, air temperature and precipitation. The prediction skill is improved when using November sea ice conditions as predictor compared to September. This is particularly true for predicting winter NAO-like patterns and blocking situations in the Euro-Atlantic area. We find that sea ice variations in Barents Sea seem to be most important for the sign of the following winter NAO—negative after low ice—but amplitude and extension of the patterns are modulated by Greenland and Labrador Seas ice areas. November ice variability in the Greenland Sea provides the best prediction skill for central and western European temperature and ice variations in the Laptev/East Siberian Seas have the largest impact on the blocking number in the Euro-Atlantic region. Over North America, prediction skill is largest using September ice areas from the Pacific Arctic sector as predictor. Composite analyses of high and low regional autumn ice conditions reveal that the atmospheric response is not entirely linear suggesting changing predictive skill dependent on sign and amplitude of the anomaly. The results confirm the importance of realistic sea ice initial conditions for seasonal forecasts. However, correlations do seldom exceed 0.6 indicating that Arctic sea ice variations can only explain a part of winter climate variations in northern mid and high latitudes. 相似文献
60.
Summary Various geodetic problems (the free nonlinear geodetic boundary value problem, the computation of Gauß-Krüger coordinates or UTM coordinates, the problem of nonlinear regression) demand theinversion of an univariate, bivariate, trivariate, in generalmultivariate homogeneous polynomial of degree n. The new algorithm which is oriented towardsSymbolic Computer Manipulation is based upon the algebraic power base computation with respect toKronecker-Zehfu product structure leading to the solution of a system oftriangular matrix equations: Only the first row of the inverse triangular matrix has to be computed. TheSymbolic Computer Manipulation program of the GKS algorithm is available from the authors. 相似文献