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71.
Martin Sudmanns Dirk Tiede Stefan Lang Helena Bergstedt Georg Trost Hannah Augustin 《International Journal of Digital Earth》2020,13(7):832-850
ABSTRACT Turning Earth observation (EO) data consistently and systematically into valuable global information layers is an ongoing challenge for the EO community. Recently, the term ‘big Earth data’ emerged to describe massive EO datasets that confronts analysts and their traditional workflows with a range of challenges. We argue that the altered circumstances must be actively intercepted by an evolution of EO to revolutionise their application in various domains. The disruptive element is that analysts and end-users increasingly rely on Web-based workflows. In this contribution we study selected systems and portals, put them in the context of challenges and opportunities and highlight selected shortcomings and possible future developments that we consider relevant for the imminent uptake of big Earth data. 相似文献
72.
Abstract The late Quaternary calcareous nannofossil assemblages from Ocean Drilling Program Holes 807A and 846B, located in the western and eastern equatorial Pacific Ocean, respectively, were analyzed to clarify changes in surface-water conditions during the last 500 000 years. The uppermost Quaternary sediments in both holes contain abundant nannofossils, and their assemblages are characterized by high species diversity. The absolute abundances of coccoliths (specimens/g) and relative numbers of small reticulofenestrids decreased drastically in both holes between 0.3 and 0.2 Ma, whereas the relative abundance of warm-water species and Florisphaera profunda increased suddenly at this time. These data indicate that upwelling around the western and eastern equatorial Pacific regions weakened after 0.2 Ma, which was caused by a decrease in trade-wind strength. 相似文献
73.
三维可视化解释技术是一项全新的地震解释技术,与传统的地震资料解释有着本质的不同,它是从三维可视化显示出发,以地质体或三维研究区块为单元,采用点、线、面和体相结合的数据体空间可视化解释。该技术结合相干体技术可进行复杂断层的解释与组合;应用空间域层位自动追踪技术能够准确落实构造形态;采用目标雕刻技术,利用反演数据体可实现立体透视岩性体的空间展布及厚度趋势。将该技术应用在大港油田官西地区复杂断块构造解释和歧南西斜坡隐蔽油气藏储层预测两项实际工作中,取得了良好效果,表明可视化解释技术在石油勘探中具有广阔的应用前景,是提高勘探效率和勘探成功率的有效技术手段。 相似文献
74.
75.
Nikolai Dotzek Peter Lang Martin Hagen Thorsten Fehr Werner Hellmiss 《Atmospheric Research》2007,83(2-4):519-533
Two downburst events from one thunderstorm are investigated, which occurred on 23 March 2001, in Germany's climatologic annual minimum of downburst activity. Observations by two Doppler radars are combined with hail reports, ground lightning detection and an aerial survey conducted after the event. The downburst-producing storm had formed at a synoptic convergence line within the warm sector of a cyclone. It had a remarkably high propagation speed of up to 31 m s− 1 corresponding to the mid-tropospheric flow. Thus, by superposition with the storm motion, even two weak downbursts were sufficient to cause the observed damage of F1 and F2 intensity, respectively. While in its late stages, the storm was dynamically characterized by lower- and mid-tropospheric divergence; at about the time of the first downburst, a mesocyclonic vortex signature was verified. Aside from mid-tropospheric dry air entrainment, a thermodynamic explanation for the triggering of the two downbursts by melting of small hail according to recent findings by Atlas et al. [Atlas, D., Ulbrich, C.W., Williams, C.R., 2004. Physical origin of a wet microburst: observations and theory. J. Atmos. Sci. 61, 1186–1196] appears probable. Despite the lack of warnings to the public, the storm's potential for hail and strong straight-line winds was detected by the German weather service radar software CONRAD more than a half hour before the downbursts occurred. 相似文献
76.
S.C. Packman B. Mauz D.-D. Rousseau P. Antoine J. Rossignol A. Lang 《Quaternary Geochronology》2007,2(1-4):39-44
Six samples were collected from a section of Peoria Loess in Eustis, North America, for optically stimulated luminescence (OSL) dating of quartz, and all except one (LV90) produced narrow dose distributions. A comparative study was conducted on this sample and on a ‘well-behaved’ sample (LV91), involving other dating methods and examination of the quartz OSL. These investigations revealed differences in the quartz OSL growth with dose, OSL response to thermal treatments and the range of components within the OSL signals. An ultra-fast component was found in LV90 that displayed a higher rate of sensitivity change than the fast component and this had a malign influence on the determination of the equivalent dose. The distinctive luminescence characteristics of LV90 imply either a change in wind dynamics and/or the source area for the silt. 相似文献
77.
78.
本文通过对三种矢量数据动态存贮方法的分析比较,并通过实践,找到一种安全可靠并且比较实用的数据动态存贮方式。 相似文献
79.
Günter Lang 《Climatic change》2007,84(3-4):423-439
Motivated by the high abatement costs of the Kyoto Protocol for Germany, this paper is estimating the economic impact of global
warming on agriculture in that country. The hedonic approach is used as theoretical background. Stating that land prices are
– among others – determined by climatic factors, this approach can consequently be used to value global warming. To avoid
a priori restrictions stemming from functional forms, the land price function is modeled as quadratic Box–Cox function that
nests a wide range of specifications. In a second step, the estimated results are used to forecast the impact of climate change.
The results indicate that German farmers will be winners of climate change in the short run, with maximum gains occurring
at a temperature increase of +0.6°C against current levels. In the long run, there may be losses from global warming. However,
the net present value from climate change is under the most probable scenarios positive. 相似文献
80.
多途径解决我国钾盐资源紧缺的对策探讨 总被引:6,自引:0,他引:6
探讨了钾盐矿产的应用,钾盐矿产在世界及我国的分布状况,提出了解决我国钾盐矿产资源紧缺问题的途径。 相似文献