Distribution of emissions allowances as an opportunity     

STEPHEN J. DECANIO 《Climate Policy》2013,13(2):91-103

Much of the debate on climate policy in the USA focuses on the gain or loss to the macroeconomy of alternative policies to reduce greenhouse gas emissions. However, the economy is made up of multiple individuals, not a single representative agent. This article reports the results of alternative ways of distributing emissions allocations across citizens. Macroeconomic effects interact with the policy for distribution, but the distributional weights are more important for the welfare of individual agents than the economy-wide effects of the emissions reductions. Egalitarian distributions of the emissions allowances have the potential to increase the welfare of most people, even if significant emissions reductions are mandated. Focusing on the distribution of emissions allowances (or the revenues generated from an emissions tax) rather than on aggregate GDP may provide guidance in identifying and implementing politically viable solutions to the climate change mitigation problem.  相似文献   

东北冷涡气候研究进展及展望     

房一禾  赵春雨  李杨  郭婷婷  李经纬  林益同  秦美欧  于怡秋 《气象与环境学报》2022,38(1):92-99

本文主要从东北冷涡气候研究角度,回顾和总结了东北冷涡在定义、主客观识别方法、气候特征、分类研究、影响因子、气候效应等方面的研究进展,并探讨了东北冷涡研究现状中存在的问题及未来可能的研究方向和发展趋势。识别与量化是东北冷涡气候研究的基础,客观识别结果的对比分析及其技术的完善是未来冷涡识别研究的重点。今后有针对性地开展不同类别东北冷涡的气候特征、异常成因及气候影响等,深入探究东北冷涡与影响因子相互作用的物理机制,科学客观的定量化预测,可为东北区域气候异常成因诊断和预测提供更精细、准确的科学依据。  相似文献   

Seismic site effects for shallow and deep alluvial basins: in-depth motion and focusing effect   总被引：1，自引：0，他引：1  

J. F. Semblat  P. Dangla  M. Kham  A. M. Duval 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):849-854

The main purpose of the paper is the analysis of seismic site effects in various alluvial basins. The analysis is performed considering a numerical approach (boundary element method). Two main cases are considered: a shallow deposit in the centre of Nice (France) [Soil Dyn. Earthquake Engng 19 (2000) 345] and a deep irregular basin in Caracas (Venezuela) [Comput. Geotech. 29 (2002) 573].

The amplification of seismic motion is analysed in terms of level, occuring frequency and location. For both sites, the amplification factor is found to reach maximum values of 20 (weak motion). Site effects nevertheless have very different features concerning the frequency dependence and the location of maximum amplification. For the shallow deposit in Nice, the amplification factor is very small for low frequencies and fastly increases above 1.0 Hz. The irregular Caracas basin gives a much different frequency dependence with many different peaks at various frequencies. The model for Caracas deep alluvial basin also includes a part of the local topography such as the nearest mountain. One can estimate seismic site effects due to both velocity contrast (between the basin and the bedrock) and local topography of the site.

Furthermore, the maximum amplification is located on the surface for Nice, whereas some strong amplification areas also appear inside the basin itself in the case of Caracas. One investigates the influence of this focusing effect on the motion versus depth dependence. This is of great interest for the analysis of seismic response of underground structures. The form and the depth of alluvial deposits are then found to have a great influence on the location of maximum amplification on the surface but also inside the deposit for deep irregular basins. It is essential for the analysis of the seismic response of both surface and underground structures.  相似文献   

滇西临沧岩基源区物质定量模拟   总被引：3，自引：0，他引：3  

刘昌实  朱金初 《岩石矿物学杂志》1989,8(1):1-12

在中国西南和东南亚领域内存在一条南北延伸的花岗岩岩基带，滇西的临沧岩体((LG) 和平和街岩体夕MG)是这一巨型同碰撞岩基带最北段的二个岩体，出露面积共约11000平方公里。 具壳源(S型)花岗岩许多特征。根据Sr, Nd同位素的上陆壳一下陆壳两端员混合摸拟，这两个岩 体的源区岩石相当于由70-80%上陆壳物质加上20-30%的下陆壳物质构成的混合物。根据Rb, Sr, Rb/Sr等微量元素和微量元素对比值在部分熔融中的行为，计算了这一源区物质约30-35%写的部分熔融形成当时的平和街和临沧岩体的初始岩浆。  相似文献   

全球变暖背景下东亚对流层顶高度演变特征的研究   总被引：2，自引：0，他引：2       下载免费PDF全文

吴涧  杨茜  符淙斌  王卫国  吴佳  许彦艳 《热带气象学报》2007,23(6):595-600

研究了1948～2004年东亚增暖背景下对流层顶高度的演变特征，重点分析对流层温度、平流层中下部温度与对流层顶高度变化之间的关系。结果表明：东亚地区对流层顶高度在1970年代后呈现波动上升趋势，其上升趋势不如南半球显著；东亚对流层温度与对流层顶高度呈显著正相关，特别是对流层中上部温度与对流层顶高度的正相关最显著，这说明对流层中上部的增温对对流层顶高度的抬升贡献较大；东亚平流层中下层温度与对流层顶高度基本呈显著负相关，70hPa层上的负相关最显著；近20年来东亚对流层温度上升了约0．2℃，平流层中下部温度下降了约1．2℃，对流顶高度上升了约86m，对流层的增暖和平流层的冷却作用共同导致了东亚对流层顶高度的变化。  相似文献   

Foreshock cavities and internal foreshock boundaries     

Laurence Billingham  Steven J. Schwartz 《Planetary and Space Science》2011,59(7):456-467

We present two case studies of cluster encounters with foreshock cavities. For one event, we are able, for the first time, to accurately relate the observation of a foreshock cavity to the measured position of the bow shock. This allows us to compute the shock angle, a vital parameter in models of foreshock cavity formation, with greater confidence than any previous study. This cavity appears to be elongated along the magnetic field and we use the multispacecraft nature of the Cluster mission to constrain its field-parallel and -perpendicular extent. We show that this event is embedded within a region of field-aligned ion beams. This is the first time a foreshock cavity has been shown to be surrounded by foreshock ion beams. A second foreshock cavity is associated with a small rotation in the interplanetary magnetic field (IMF). We show that this event appears on the boundary between an interval when the spacecraft were inside the ion foreshock, and an excursion upstream. This is the first report of a foreshock cavity observed during the traversal of the global foreshock. This second event has some features expected from the new Sibeck et al. (2008) model of cavities as brief encounters with a spatial boundary in the global foreshock.  相似文献   

Magnetohydrodynamic study of shock waves in the current sheet of a solar coronal magnetic loop     

Ü.D. Göker 《New Astronomy》2012,17(2):130-136

A Lagrangian Remap (LareXd) Code is employed to investigate the shock wave formation in the current sheet of a solar coronal magnetic loop and its effect on the magnetic reconnection. We constructed the slow shock structure in the presence of viscosity and heat conduction parallel and perpendicular to the magnetic field and pairs of slow shocks propagate away from the central current sheet, the so-called diffusion region. Significant jumps in plasma density, pressure, velocity and magnetic field occur across the main shock while the temperature appears in the foreshock. In the presence of dissipative effects, the distinct jumps disappear and the shock profiles show smooth transition between the downstream and the upstream regions while the plasma density and the pressure show very narrow and a sharp decrease with time. These results can be applied to the heating of the solar corona, the structure of the magnetic reconnection and the solar wind.  相似文献   

Effects of three-dimensionality on seismic response of Gaussian-shaped hills for simple incident pulses     

《Soil Dynamics and Earthquake Engineering》2013

In this paper the boundary element algorithm which uses the time-convoluted traction kernels is applied to a numerical parametric study on the seismic behavior of three-dimensional Gaussian-shaped hills subjected to vertically propagating incident waves. All calculations were executed in the time-domain and the medium was assumed to have a linear elastic constitutive behavior. Results are discussed in both time and frequency domain with respect to the dimensionless parameters. It was shown that wave length and site geometry, including shape and dimension ratios and, to some extent, wave type are the key independent parameters governing hill amplification behavior. Comparing two- and three-dimensional hills with similar shape ratios, two-dimensional hill had greater characteristic periods, where the three-dimensional hill had greater maximum amplification potential. Three-dimensionality has a strong effect on the seismic responses of the hill; however the rate of seismic response variation with the three-dimensionality factor depends on the shape ratio. It was shown that two-dimensional behavior was dominant in low height three-dimensional hills, however, as the shape ratio increased, three-dimensionality effects appeared and the seismic response of the hill tends toward the axisymmetric three-dimensional hill.  相似文献   

Preliminary results of strong ground motion simulation for the Lushan earthquake of 20 April 2013, China     

Gengshang Zhu  Zhenguo Zhang  Jian Wen  Wei Zhang  Xiaofei Chen 《地震学报(英文版)》2013,(3):191-197

The earthquake occurred in Lushan County on 20 April, 2013 caused heavy casualty and economic loss. In order to understand how the seismic energy propagates during this earthquake and how it causes the seismic haz- ard, we simulated the strong ground motions from a rep- resentative kinematic source model by Zhang et al. （Chin J Geophys 56（4）：1408-1411, 2013） for this earthquake. To include the topographic effects, we used the curved grids finite difference method by Zhang and Chen （Geophys J Int 167（1）：337-353, 2006）, Zhang et al. （Geophys J Int 190（1）：358-378, 2012） to implement the simulations. Our results indicated that the majority of seismic energy con- centrated in the epicentral area and the vicinal Sichuan Basin, causing the XI and VII degree intensity. Due to the strong topographic effects of the mountain, the seismic intensity in the border area across the northeastern of Boxing County to the Lushan County also reached IX degree. Moreover, the strong influence of topography caused the amplifications of ground shaking at the moun- tain ridge, which is easy to cause landslides. These results are quite similar to those observed in the Wenchuan earthquake of 2008 occurred also in a strong topographic mountain area.  相似文献   

VS30, site amplifications and some comparisons: The Adapazari (Turkey) case     

《Physics and Chemistry of the Earth》2013

The aim of this study was to investigate the role of V_S30 in site amplifications in the Adapazari region, Turkey. To fulfil this aim, amplifications from V_S30 measurements were compared with earthquake data for different soil types in the seismic design codes. The Adapazari area was selected as the study area, and shear-wave velocity distribution was obtained by the multichannel analysis of surface waves (MASWs) method at 100 sites for the top 50 m of soil. Aftershock data following the Mw 7.4 Izmit earthquake of 17 August 1999 gave magnitudes between 4.0 and 5.6 at six stations installed in and around the Adapazari Basin, at Babalı, Şeker, Genç, Hastane, Toyota and Imar. This data was used to estimate site amplifications by the reference-station method. In addition, the fundamental periods of the station sites were estimated by the single station method. Site classifications based on V_S30 in the seismic design codes were compared with the fundamental periods and amplification values. It was found that site amplifications (from earthquake data) and relevant spectra (from V_S30) are not in good agreement for soils in Adapazari (Turkey).  相似文献