Stabilization and global climate policy   总被引：1，自引：0，他引：1  

Marcus C. Sarofim  Chris E. Forest  David M. Reiner  John M. Reilly 《Global and Planetary Change》2005,47(2-4):266

Academic and political debates over long-run climate policy often invoke “stabilization” of atmospheric concentrations of greenhouse gases (GHGs), but only rarely are non-CO₂ greenhouse gases addressed explicitly. Even though the majority of short-term climate policies propose trading between gases on a global warming potential (GWP) basis, discussions of whether CO₂ concentrations should be 450, 550, 650 or perhaps as much as 750 ppm leave unstated whether there should be no additional forcing from other GHGs beyond current levels or whether separate concentration targets should be established for each GHG. Here, we use an integrated modeling framework to examine multi-gas stabilization in terms of temperature, economic costs, carbon uptake and other important consequences. We show that there are significant differences in both costs and climate impacts between different “GWP equivalent” policies and demonstrate the importance of non-CO₂ GHG reduction on timescales of up to several centuries.  相似文献   

Scattering of radiation by a large particle with a random rough surface     

Sonoyo Mukai  Tadashi Mukai  Richard H. Giese  Karin Weiss  Reiner H. Zerull 《Earth, Moon, and Planets》1982,26(2):197-208

Intensity and polarization of scattered light by an absorbing spherical particle with a random rough surface and with a radius larger than the wavelength of radiation are investigated. Multiple reflections of incident light on the rough surface are treated based on the multiple scattering theory.Within the limits of our approximation the model gives good agreement with typical scattering features by irregular shaped particles derived by microwave analogue experiments and laser measurements, namely a backward enhancement of the intensity, and a reduction of magnitude of polarization.Our treatment will be provide a powerful tool for studying scattering problems of interstellar and/or interplanetary grains as well as those of asteroids and the Moon.  相似文献   

Transformation of global spherical harmonic models of the gravity field to a local adjusted spherical cap harmonic model     

Ghadi K. A. Younis  Reiner Jäger  Matthias Becker 《Arabian Journal of Geosciences》2013,6(2):375-381

The new global gravity models represented by global spherical harmonics like EGM2008 require a high degree and order in their coefficients to resolve the gravity field in local areas; therefore, there are interests to represent the regional or local field by less parameters and to develop a parameter transformation from the global model to a local kind of spherical harmonic model. The authors use local spherical cap harmonics for the regional gravity potential representation related to a local pole and a local spherical coordinate system. This allows to model regional gravity potential with less parameters and less memory requirements in computation and storage. From different kinds of representations of spherical cap harmonics, we have selected the so-called adjusted spherical cap harmonics (ASCH). This is the most appropriate for the presented mathematical model of deriving its coefficients from global gravity models. In that way, the global gravity models can fully be exploited and mapped to regional ASCH, in particular with respect to the computation of regional geoid models with improved solution.  相似文献   

Weathering of volcanic tuff rocks caused by moisture expansion   总被引：1，自引：1，他引：0  

Wanja Wedekind  Rubén López-Doncel  Reiner Dohrmann  Mathias Kocher  Siegfried Siegesmund 《Environmental Earth Sciences》2013,69(4):1203-1224

Moisture expansion in natural building stones is considered one of the most important factors affecting their weathering and deterioration. The processes that may be responsible for the expansion under determinate relative humidity (hygric dilatation) and water-saturated conditions (hydric dilatation) are generally attributed to the presence of swellable clay minerals. In contrast to this assumption, our investigations show that moisture expansion also takes place in volcanic tuff building stones almost free from clay minerals. To provide a deeper understanding of the processes, swelling and deterioration were performed on 14 volcanic tuffs used as important building stones of different ages, compositions and weathering stages from Mexico, Germany and Hungary. The investigations undertaken include extensive chemical, petrophysical and fabric analyses. The samples show a wide range of effective porosity, microporosity, capillary water absorption, moisture expansion, and CEC values. High moisture expansion does not seem to depend on clay mineral content alone. We also observed that there is no significant effect on dilatation if clay minerals are present but only form a thin coat on the outer shell of bigger pores. Moreover, we identified a correlation between microporosity, average pore radius and moisture expansion. The investigations highlight the fact that moisture expansion cannot only be attributed to swellable clay minerals, and suggest that the presence and accumulation of micropores and their average radius and distribution play an important role for non-clay associated swelling intensity, which can most probably be attributed to the disjoining pressure.  相似文献   

Evidence for halo-like radio sources from kilometric type III burst observations     

M. J. Reiner  R. G. Stone 《Solar physics》1990,125(2):371-388

The radio azimuths for many kilometric type III bursts that originate near or behind the limb of the Sun are observed to drift far to the east or far to the west of the spacecraft-Sun line. It is shown that the behavior of the observed burst parameters for these events corresponds to the response of a spinning dipole antenna to halo-like sources of radiation around the Sun. Our results provide evidence for a previous suggestion that behind-the-limb type III events should appear as halo-like sources of radiation to an observer on the opposite side of the Sun, due to scattering of the radiation from the primary source back around the Sun.  相似文献   

Book reviews     

A. Zaporozec  E. M. Yates  H. Tietze  Ernst Reiner  N. R. Seifried 《GeoJournal》1984,9(3):254-320

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Origin of the deep fluids in the paleosubduction zones in western Tianshan: Evidence from Pb- and Sr-isotope compositions of high-pressure veins and host rocks     

Reiner Klemd 《中国科学D辑(英文版)》2005,48(10)

Fluids in the deep subduction zones play an impor-tant role in the process of crust-mantle interaction. This has been proved by a large number of studies on the geochemistry of island arc volcanic rocks[1―9]. Study on high-pressure metamorphic rocks within orogen shows that the dehydration and devolatilization of subducted oceanic crust and sediments can release amounts of water during progressive metamorph- ism[10―13]. The origin of the fluids in the subduction zones provides important info…  相似文献   

The relation between degree-2160 spectral models of Earth’s gravitational and topographic potential: a guide on global correlation measures and their dependency on approximation effects     

Christian?HirtEmail author  Moritz?Rexer  Sten?Claessens  Reiner?Rummel 《Journal of Geodesy》2017,91(10):1179-1205

Comparisons between high-degree models of the Earth’s topographic and gravitational potential may give insight into the quality and resolution of the source data sets, provide feedback on the modelling techniques and help to better understand the gravity field composition. Degree correlations (cross-correlation coefficients) or reduction rates (quantifying the amount of topographic signal contained in the gravitational potential) are indicators used in a number of contemporary studies. However, depending on the modelling techniques and underlying levels of approximation, the correlation at high degrees may vary significantly, as do the conclusions drawn. The present paper addresses this problem by attempting to provide a guide on global correlation measures with particular emphasis on approximation effects and variants of topographic potential modelling. We investigate and discuss the impact of different effects (e.g., truncation of series expansions of the topographic potential, mass compression, ellipsoidal versus spherical approximation, ellipsoidal harmonic coefficient versus spherical harmonic coefficient (SHC) representation) on correlation measures. Our study demonstrates that the correlation coefficients are realistic only when the model’s harmonic coefficients of a given degree are largely independent of the coefficients of other degrees, permitting degree-wise evaluations. This is the case, e.g., when both models are represented in terms of SHCs and spherical approximation (i.e. spherical arrangement of field-generating masses). Alternatively, a representation in ellipsoidal harmonics can be combined with ellipsoidal approximation. The usual ellipsoidal approximation level (i.e. ellipsoidal mass arrangement) is shown to bias correlation coefficients when SHCs are used. Importantly, gravity models from the International Centre for Global Earth Models (ICGEM) are inherently based on this approximation level. A transformation is presented that enables a transformation of ICGEM geopotential models from ellipsoidal to spherical approximation. The transformation is applied to generate a spherical transform of EGM2008 (sphEGM2008) that can meaningfully be correlated degree-wise with the topographic potential. We exploit this new technique and compare a number of models of topographic potential constituents (e.g., potential implied by land topography, ocean water masses) based on the Earth2014 global relief model and a mass-layer forward modelling technique with sphEGM2008. Different to previous findings, our results show very significant short-scale correlation between Earth’s gravitational potential and the potential generated by Earth’s land topography (correlation +0.92, and 60% of EGM2008 signals are delivered through the forward modelling). Our tests reveal that the potential generated by Earth’s oceans water masses is largely unrelated to the geopotential at short scales, suggesting that altimetry-derived gravity and/or bathymetric data sets are significantly underpowered at 5 arc-min scales. We further decompose the topographic potential into the Bouguer shell and terrain correction and show that they are responsible for about 20 and 25% of EGM2008 short-scale signals, respectively. As a general conclusion, the paper shows the importance of using compatible models in topographic/gravitational potential comparisons and recommends the use of SHCs together with spherical approximation or EHCs with ellipsoidal approximation in order to avoid biases in the correlation measures.  相似文献   

Mediterranean physical oceanography and biogeochemical cycles: General circulation and climate variability     

Joaquín Tintor  Guest Editors  Alberto Alvarez  Reiner Onken  Guest Editor 《Progress in Oceanography》2005,66(2-4):87

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Transport of South Atlantic water through the passages south of Guadeloupe and across 16°N, 2000–2004   总被引：1，自引：1，他引：1  

Monika Rhein  Kerstin Kirchner  Christian Mertens  Reiner Steinfeldt  Maren Walter  Ulrich Fleischmann-Wischnath 《Deep Sea Research Part I: Oceanographic Research Papers》2005,52(12):2234-2249

CTD, vessel-mounted ADCP and LADCP measurements in the Caribbean passages south of Guadeloupe (three repeats) and along 16°N (five repeats) were carried out between December 2000 and July 2004. The CTD data were used to calculate the contribution of South Atlantic water (SAW) in the upper 1200 m between the isopycnals σ_θ=24.5 and 27.6. Northern and southern source water masses are defined and an isopycnal mixing approach is applied. The SAW fractions are then combined with the ADCP flow field to calculate the transport of SAW into the Caribbean and across 16°N. The SAW inflow into the Caribbean through the passages south of Guadeloupe ranges from 7.6 to 11.6 Sv, which is 50–75% of the total inflow. The mean (9.1±2.2 Sv) is in the range of previous estimates. Ambiguities in the northern and southern source water masses of the salinity maximum water permitted us only to calculate the contribution of SAW from the eastern source in this water mass. We estimated the additional SAW transport by the western source to be of the order of 1.9±0.7 Sv. The calculation of the SAW transport across 16°N was hampered by the presence of several anticyclonic rings from the North Brazil Current (NBC) retroflection region, some of the rings were subsurface intensified. Provided that the rings observed at 16°N are typical rings and that all rings which are annually produced in the NBC retroflection area (6.5–8.5 per year) reach 16°N, the SAW ring transport across 16°N is calculated to 5.3±0.7 Sv. From the 5 repeats at 16°N, only two showed a net northward flow, suggesting that the mean northward SAW transport is dominated by ring advection. The joint SAW transports of the Caribbean inflow (9.1 Sv) and the flow across 16°N (5.3 Sv) sum up to 14.4 Sv. The transport increases to 16.3 Sv if the additional SAW transport from the western source of SMW (1.9±0.7 Sv) is included. These transport estimates and the following implications depend strongly on the assumption that the surface water in the Caribbean inflow is of South Atlantic origin. The transport estimates are, however, in the range of the inverse model calculations for the net cross-hemispheric flow. About 30–40% of this transport is intermediate water from the South Atlantic, presumably supporting studies which found the contributions of intermediate and upper warm water to be of a comparable magnitude. For the upper warm water (σ_θ<27.1), the Caribbean inflow seems to be the major path (7.9±1.6 Sv), the ring induced transport across 16°N is about 30% of that value. The intermediate water transport across 16°N was calculated to be 2.3–3.6 Sv, the inflow into the Caribbean is slightly smaller (1.5–2.4 Sv).  相似文献