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31.
The climatic impacts of land surface change and carbon management, and the implications for climate-change mitigation policy 总被引:4,自引:0,他引:4
Strategies to mitigate anthropogenic climate change recognize that carbon sequestration in the terrestrial biosphere can reduce the build-up of carbon dioxide in the Earth’s atmosphere. However, climate mitigation policies do not generally incorporate the effects of these changes in the land surface on the surface albedo, the fluxes of sensible and latent heat to the atmosphere, and the distribution of energy within the climate system. Changes in these components of the surface energy budget can affect the local, regional, and global climate. Given the goal of mitigating climate change, it is important to consider all of the effects of changes in terrestrial vegetation and to work toward a better understanding of the full climate system. Acknowledging the importance of land surface change as a component of climate change makes it more challenging to create a system of credits and debits wherein emission or sequestration of carbon in the biosphere is equated with emission of carbon from fossil fuels. Recognition of the complexity of human-caused changes in climate does not, however, weaken the importance of actions that would seek to minimize our disturbance of the Earth’s environmental system and that would reduce societal and ecological vulnerability to environmental change and variability. 相似文献
32.
Construction of Green's function to the external Dirichlet boundary-value problem for the Laplace equation on an ellipsoid of revolution 总被引:1,自引:0,他引:1
Green's function to the external Dirichlet boundary-value problem for the Laplace equation with data distributed on an ellipsoid
of revolution has been constructed in a closed form. The ellipsoidal Poisson kernel describing the effect of the ellipticity
of the boundary on the solution of the investigated boundary-value problem has been expressed as a finite sum of elementary
functions which describe analytically the behaviour of the ellipsoidal Poisson kernel at the singular point ψ = 0. We have
shown that the degree of singularity of the ellipsoidal Poisson kernel in the vicinity of its singular point is of the same
degree as that of the original spherical Poisson kernel.
Received: 4 June 1996 / Accepted: 7 April 1997 相似文献
33.
着重介绍了CuInSe2的结构和光、电学特性;讨论了多各上薄膜沉积技术;评价了主要的合成装置及其作途;综述了制备CuInSe2太阳电池器件的工艺和材料,提出了一种能成功地生产大面积太阳电池薄膜的经济有铲的沉积技术。 相似文献
34.
In order to model flow and transport in fractured rocks it is important to know the geometry of the fracture network. A stochastic approach is commonly used to generate a synthetic fracture network from the statistics measured at a natural fracture network. The approach presented herein is able to incorporate the structures found in a natural fracture network into the synthetic fracture network. These synthetic fracture networks are the images generated by Iterated Function Systems (IFS) as introduced by Barnsley (1988). The conditions these IFS have to fulfil to determine images resembling fracture networks and the effects of their parameters on the images are discussed. It is possible to define the parameters of the IFS in order to generate some properties of a fracture network. The image of an IFS consists of many single points and has to be suitably processed for further use. 相似文献
35.
Measurements of the activation energy of electrical conductance and desiccation rates on subtidal marine algae from Florida
were compared to similar data from the Bay of Fundy, Nova Scotia, on intertidal marine algae frequently subjected to long
periods of exposure to air. We have developed a method for calculating the reaction rate constant of desiccation of fully
hydrated marine algae. Values of activation energies and desiccation rate constants are consistent with the requirements for
survival of these algae under widely different environmental conditions. 相似文献
36.
37.
38.
A rippability classification system for marls in lignite mines 总被引:1,自引:0,他引:1
39.
Abstract Spatial and temporal variations in radiative fluxes influence glacier mass‐balance in mountain areas. The primary goal of this study was to assess differences in solar radiation on three glacial cirques located in the Maladeta Mountain massif (Central Spanish Pyrenees), and analyse their implications on glacier development and morphology. A quantitative approach is adopted to obtain the values of solar radiation (direct, diffuse and global radiation), combining several field data parameters (measured at 55 control‐points) with the solar radiation modelling package Ecosim. The data obtained confirm that the morphologies of the glacial bodies developed in the three cirques have a good correlation with the spatial variation on solar radiation inputs, favouring also the conservation (Aneto and Coronas cirques) or total vanishing (Llosás cirque) of the glacial remnants analysed here. The study shows how strongly in this Alpine‐Mediterranean context solar radiation — firstly as a function of latitude and time of year, and locally as a function of topographic slope, aspect and shadowing — controls the mass‐balance and the spatial distribution of melting in small glaciers, having an effect on the development of their morphologies. 相似文献
40.
通过实例推导幂函数对建筑物沉降进行回归分析,并且得出较为精确的结果,同时也说明在选择回归函数的时候,还会受到很多条件影响。 相似文献