The origin of the galaxy mass–metallicity relation and implications for galactic outflows     

Kristian Finlator  Romeel Davé 《Monthly notices of the Royal Astronomical Society》2008,385(4):2181-2204

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The feasibility of low CO₂ concentration targets and the role of bio-energy with carbon capture and storage (BECCS)     

Christian Azar  Kristian Lindgren  Michael Obersteiner  Keywan Riahi  Detlef P. van Vuuren  K. Michel G. J. den Elzen  Kenneth M?llersten  Eric D. Larson 《Climatic change》2010,100(1):195-202

The United Nations Framework Convention on Climate Change (UNFCCC 1992) calls for stabilization of atmospheric greenhouse gas (GHG) concentrations at a level that would prevent dangerous anthropogenic interference with the climate system. We use three global energy system models to investigate the technological and economic attainability of meeting CO₂ concentration targets below current levels. Our scenario studies reveal that while energy portfolios from a broad range of energy technologies are needed to attain low concentrations, negative emission technologies—e.g., biomass energy with carbon capture and storage (BECCS)—significantly enhances the possibility to meet low concentration targets (at around 350 ppm CO₂).  相似文献   

Climate change impacts on water management and irrigated agriculture in the Yakima River Basin, Washington, USA   总被引：1，自引：0，他引：1  

Julie A. Vano  Michael J. Scott  Nathalie Voisin  Claudio O. Stöckle  Alan F. Hamlet  Kristian E. B. Mickelson  Marketa McGuire Elsner  Dennis P. Lettenmaier 《Climatic change》2010,102(1-2):287-317

The Yakima River Reservoir system supplies water to ~180,000 irrigated hectares through the operation of five reservoirs with cumulative storage of ~30% mean annual river flow. Runoff is derived mostly from winter precipitation in the Cascade Mountains, much of which is stored as snowpack. Climate change is expected to result in earlier snowmelt runoff and reduced summer flows. Effects of these changes on irrigated agriculture were simulated using a reservoir system model coupled to a hydrological model driven by downscaled scenarios from 20 climate models archived by the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. We find earlier snowmelt results in increased water delivery curtailments. Historically, the basin experienced substantial water shortages in 14% of years. Without adaptations, for IPCC A1B global emission scenarios, water shortages increase to 27% (13% to 49% range) in the 2020s, to 33% in the 2040s, and 68% in the 2080s. For IPCC B1 emissions scenarios, shortages occur in 24% (7% to 54%) of years in the 2020s, 31% in the 2040s and 43% in the 2080s. Historically unprecedented conditions where senior water rights holders suffer shortfalls occur with increasing frequency in both A1B and B1 scenarios. Economic losses include expected annual production declines of 5%–16%, with greater probabilities of operating losses for junior water rights holders.  相似文献   

Coarse-scale data assimilation as a generic alternative to localization     

Kristian Fossum  Trond Mannseth 《Computational Geosciences》2017,21(1):167-186

Coarse-scale data assimilation (DA) with large ensemble size is proposed as a robust alternative to standard DA with localization for reservoir history matching problems. With coarse-scale DA, the unknown property function associated with each ensemble member is upscaled to a grid significantly coarser than the original reservoir simulator grid. The grid coarsening is automatic, ensemble-specific and non-uniform. The selection of regions where the grid can be coarsened without introducing too large modelling errors is performed using a second-generation wavelet transform allowing for seamless handling of non-dyadic grids and inactive grid cells. An inexpensive local-local upscaling is performed on each ensemble member. A DA algorithm that restarts from initial time is utilized, which avoids the need for downscaling. Since the DA computational cost roughly equals the number of ensemble members times the cost of a single forward simulation, coarse-scale DA allows for a significant increase in the number of ensemble members at the same computational cost as standard DA with localization. Fixing the computational cost for both approaches, the quality of coarse-scale DA is compared to that of standard DA with localization (using state-of-the-art localization techniques) on examples spanning a large degree of variability. It is found that coarse-scale DA is more robust with respect to variation in example type than each of the localization techniques considered with standard DA. Although the paper is concerned with two spatial dimensions, coarse-scale DA is easily extendible to three spatial dimensions, where it is expected that its advantage with respect to standard DA with localization will increase.  相似文献   

Catastrophic Events and Stochastic Cost-benefit Analysis of Climate Change   总被引：1，自引：1，他引：0  

Crhistian Azar  Kristian Lindgren 《Climatic change》2003,56(3):245-255

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Will the Clean Development Mechanism be effectively implemented in China?     

Kristian Tangen  Gørild Heggelund 《Climate Policy》2003,3(3):303-307

The on-going process of setting up a national system for identification, approval and implementation of CDM-projects in China illustrates the changes in the Chinese attitude towards the CDM after COP7. This is a very important process, and the outcome could strongly influence investors’ willingness to invest in Chinese CDM-projects. The massive interest and capacity building by international assistance organisations, bilateral and multilateral donors, for preparing the implementation of the CDM will provide China with information and experience. Nevertheless, potential factors that may negatively influence efficient implementation of CDM-projects are: the domestic implementation system is not yet finalised and may impact on China’s ability to compete for CDM-projects; the priorities of the Chinese authorities may not match those of foreign investors; the main expertise regarding CDM is found in a few ministries and research institutes in Beijing, and there is a need to increase capacity for CDM among local project developers and authorities; most research carried out concerned technical issues, and there is a need to include economists and market experts in order to increase understanding of the market.  相似文献   

Plasma Instabilities in the Ionospheric E-region     

Kristian Schlegel  D. T. Farley  A. V. Gurevich  C. Haldoupis 《Annales Geophysicae》1997,15(7):855-855

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ACTIVITY CONCERNING BLACK AMERICA IN UNIVERSITY DEPARTMENTS GRANTING M.A. AND PH.D. DEGREES IN GEOGRAPHY *     

Ronald J. Horvath  Donald R. Deskins  Ann E. Larimore 《The Professional geographer》1969,21(3):137-139

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Distribution and effects on hepatic xenobiotic metabolizing enzymes of 2,3,3′,4,4′- pentachlorobiphenyl (PCB-105) in cod (Gadus morhua) and rainbow trout (Oncorhynchus mykiss)     

Aksel Bernhoft  Halvor Hektoen  Janneche Utne Skaare  Kristian Ingerbrigtsen 《Marine environmental research》1995,39(1-4)

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Numerical prediction of green water incidents     

Kristian Bendix Nielsen  Stefan Mayer 《Ocean Engineering》2004,31(3-4):363-399

Green water loads on moored or sailing ships occur when an incoming wave significantly exceeds the freeboard and water runs onto the deck. In this paper, a Navier–Stokes solver with a free surface capturing scheme (i.e. the VOF model; [Hirt and Nichols, 1981]) is used to numerically model green water loads on a moored FPSO exposed to head sea waves. Two cases are investigated: first, green water on a fixed vessel has been analysed, where resulting waterheight on deck, and impact pressure on a deck mounted structure have been computed. These results have been compared to experimental data obtained by [Greco, 2001] and show very favourable agreement. Second, a full green water incident, including vessel motions has been modelled. In these computations, the vertical motion has been modelled by the use of transfer functions for heave and pitch, but the rotational contribution from the pitch motion has been neglected. The computed water height on deck has been compared to the experimental data obtained by [Buchner, 1995a] and it also shows very good agreement. The modelling in the second case was performed in both 2-D and 3-D with very similar results, which indicates that 3-D effects are not dominant.  相似文献