Climate Change Impacts for the Conterminous USA: An Integrated Assessment: From Mink to the ‘Lower 48’     

Norman J. Rosenberg  James A. Edmonds 《Climatic change》2005,69(1):1-6

  相似文献   

Coordinated Akebono and EISCAT observations of suprathermal ion outflows in the nightside inverted-V region     

《Journal of Atmospheric and Solar》2000,62(6):449-465

We have investigated ion outflows observed by the Akebono satellite and the EISCAT radar in the nightside auroral region on February 16, 1993. The Akebono satellite at about 7000 km altitude observed the region of suprathermal ion outflows and inverted-V type electron precipitation alternately with a horizontal separation of 70–150 km at the ionospheric level. These two regions corresponded to the upward and downward field-aligned current region, respectively, and intense ELF waves were observed in the ion outflow region. From the EISCAT VHF radar observation (Common Program 7 mode), it has been suggested that the ion outflow region and the enhanced electron temperature region were aligned along geomagnetic field lines with vertical and horizontal separations of 200–400 and 70–80 km, respectively and these two regions convected equatorward across the EISCAT radar at Tromsø site. Based on these results, we propose a model for this ion outflow as follows. In the nightside auroral region, downward FAC regions exist near the edge of the inverted-V type electron precipitation regions. ELF waves are excited probably by a plasma instability due to the upward thermal electron beam carrying the downward FACs, and these ELF waves cause transverse ion heating at the top of the ionosphere. The produced ion conics contribute significantly to ion outflow.  相似文献   

The Indian Subcontinent and Gondwana: A Palaeomagnetic and Rock Magnetic Perspective | The Indian Subcontinent and Gondwana: A Palaeomagnetic and Rock Magnetic Perspective,T. Radhakrishna,J.D.A. Piper (Eds.), Memoir 44, Geological Society of India,Bangalore (1999), 270p.     

《Gondwana Research》2000,3(2):281-283

  相似文献   

Erratum to: Simulation of monsoon intraseasonal variability in NCEP CFSv2 and its role on systematic bias     

Bidyut B. Goswami  Medha Deshpande  P. Mukhopadhyay  Subodh K. Saha  Suryachandra A. Rao  Raghu Murtugudde  B. N. Goswami 《Climate Dynamics》2015,44(3-4):1171-1171

  相似文献   

Effects of cumulus parameterizations on predictions of summer flood in the Central United States   总被引：1，自引：0，他引：1  

Fengxue Qiao  Xin-Zhong Liang 《Climate Dynamics》2015,45(3-4):727-744

  相似文献   

On the use of multi‐algorithm,genetically adaptive multi‐objective method for multi‐site calibration of the SWAT model     

Xuesong Zhang  Raghavan Srinivasan  Michael Van Liew 《水文研究》2010,24(8):955-969

With the availability of spatially distributed data, distributed hydrologic models are increasingly used for simulation of spatially varied hydrologic processes to understand and manage natural and human activities that affect watershed systems. Multi‐objective optimization methods have been applied to calibrate distributed hydrologic models using observed data from multiple sites. As the time consumed by running these complex models is increasing substantially, selecting efficient and effective multi‐objective optimization algorithms is becoming a nontrivial issue. In this study, we evaluated a multi‐algorithm, genetically adaptive multi‐objective method (AMALGAM) for multi‐site calibration of a distributed hydrologic model—Soil and Water Assessment Tool (SWAT), and compared its performance with two widely used evolutionary multi‐objective optimization (EMO) algorithms (i.e. Strength Pareto Evolutionary Algorithm 2 (SPEA2) and Non‐dominated Sorted Genetic Algorithm II (NSGA‐II)). In order to provide insights into each method's overall performance, these three methods were tested in four watersheds with various characteristics. The test results indicate that the AMALGAM can consistently provide competitive or superior results compared with the other two methods. The multi‐method search framework of AMALGAM, which can flexibly and adaptively utilize multiple optimization algorithms, makes it a promising tool for multi‐site calibration of the distributed SWAT. For practical use of AMALGAM, it is suggested to implement this method in multiple trials with relatively small number of model runs rather than run it once with long iterations. In addition, incorporating different multi‐objective optimization algorithms and multi‐mode search operators into AMALGAM deserves further research. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Processes Leading to Second-Year Cooling of the 2010–12 La Ni?a Event,Diagnosed Using GODAS     

FENG Licheng  ZHANG Rong-Hua  WANG Zhanggui  CHEN Xingrong 《大气科学进展》2015,32(3):424-438

Isopycnal analyses were performed on the Global Ocean Data Assimilation System(GODAS) to determine the oceanic processes leading to so-called second-year cooling of the La Nina event. In 2010–12, a horseshoe-like pattern was seen,connecting negative temperature anomalies off and on the Equator, with a dominant influence from the South Pacific. During the 2010 La Nina event, warm waters piled up at subsurface depths in the western tropical Pacific. Beginning in early 2011,these warm subsurface anomalies propagated along the Equator toward the eastern basin, acting to reverse the sign of sea surface temperature(SST) anomalies(SSTAs) there and initiate a warm SSTA. However, throughout early 2011, pronounced negative anomalies persisted off the Equator in the subsurface depths of the South Pacific. As isopycnal surfaces outcropped in the central equatorial Pacific, negative anomalies from the subsurface spread upward along with mean circulation pathways, naturally initializing a cold SSTA. In the summer, a cold SSTA reappeared in the central basin, which subsequently strengthened due to the off-equatorial effects mostly in the South Pacific. These SSTAs acted to initiate local coupled air–sea interactions, generating atmospheric–oceanic anomalies that developed and evolved with the second-year cooling in the fall of 2011. However, the cooling tendency in mid-2012 did not develop into another La Nina event, since the cold anomalies in the South Pacific were not strong enough. An analysis of the 2007–09 La Nina event revealed similar processes to the2010–12 La Nina event.  相似文献   

SST and ENSO variability and change simulated in historical experiments of CMIP5 models   总被引：1，自引：1，他引：0  

Bhaskar Jha  Zeng-Zhen Hu  Arun Kumar 《Climate Dynamics》2014,42(7-8):2113-2124

This work documents the diversity in Coupled Model Inter-comparison Project Phase 5 (CMIP5) models in simulating different aspects of sea surface temperature (SST) variability, particularly those associated with the El Niño–Southern Oscillation (ENSO), as well as the impact of low-frequency variations on the ENSO variability and its global teleconnection. The historical simulations (1870–2005) include 10 models with ensemble member ranging from 3 to 10 that are forced with observed atmospheric composition changes reflecting both natural and anthropogenic forcings. It is shown that the majority of the CMIP5 models capture the relative large SST anomaly variance in the tropical central and eastern Pacific, as well as in North Pacific and North Atlantic. The frequency of ENSO is not well captured by almost all models, particularly for the period of 5–6 years. The low-frequency variations in SST caused by external forcings affect the SST variability and also modify the global teleconnection of ENSO. The models reproduce the global averaged SST low-frequency variations, particularly since 1970s. However, majority of the models are unable to correctly simulate the spatial pattern of the observed SST trends. These results suggest that it is still a challenge to reproduce the features of global historical SST variations with the state-of-the-art coupled general circulation model.  相似文献   

The representative concentration pathways: an overview   总被引：20，自引：4，他引：16  

Detlef P. van Vuuren  Jae Edmonds  Mikiko Kainuma  Keywan Riahi  Allison Thomson  Kathy Hibbard  George C. Hurtt  Tom Kram  Volker Krey  Jean-Francois Lamarque  Toshihiko Masui  Malte Meinshausen  Nebojsa Nakicenovic  Steven J. Smith  Steven K. Rose 《Climatic change》2011,109(1-2):5-31

This paper summarizes the development process and main characteristics of the Representative Concentration Pathways (RCPs), a set of four new pathways developed for the climate modeling community as a basis for long-term and near-term modeling experiments. The four RCPs together span the range of year 2100 radiative forcing values found in the open literature, i.e. from 2.6 to 8.5 W/m². The RCPs are the product of an innovative collaboration between integrated assessment modelers, climate modelers, terrestrial ecosystem modelers and emission inventory experts. The resulting product forms a comprehensive data set with high spatial and sectoral resolutions for the period extending to 2100. Land use and emissions of air pollutants and greenhouse gases are reported mostly at a 0.5?×?0.5 degree spatial resolution, with air pollutants also provided per sector (for well-mixed gases, a coarser resolution is used). The underlying integrated assessment model outputs for land use, atmospheric emissions and concentration data were harmonized across models and scenarios to ensure consistency with historical observations while preserving individual scenario trends. For most variables, the RCPs cover a wide range of the existing literature. The RCPs are supplemented with extensions (Extended Concentration Pathways, ECPs), which allow climate modeling experiments through the year 2300. The RCPs are an important development in climate research and provide a potential foundation for further research and assessment, including emissions mitigation and impact analysis.  相似文献   

The RCP greenhouse gas concentrations and their extensions from 1765 to 2300   总被引：16，自引：2，他引：14  

Malte Meinshausen  S. J. Smith  K. Calvin  J. S. Daniel  M. L. T. Kainuma  J-F. Lamarque  K. Matsumoto  S. A. Montzka  S. C. B. Raper  K. Riahi  A. Thomson  G. J. M. Velders  D.P. P. van Vuuren 《Climatic change》2011,109(1-2):213-241

We present the greenhouse gas concentrations for the Representative Concentration Pathways (RCPs) and their extensions beyond 2100, the Extended Concentration Pathways (ECPs). These projections include all major anthropogenic greenhouse gases and are a result of a multi-year effort to produce new scenarios for climate change research. We combine a suite of atmospheric concentration observations and emissions estimates for greenhouse gases (GHGs) through the historical period (1750?C2005) with harmonized emissions projected by four different Integrated Assessment Models for 2005?C2100. As concentrations are somewhat dependent on the future climate itself (due to climate feedbacks in the carbon and other gas cycles), we emulate median response characteristics of models assessed in the IPCC Fourth Assessment Report using the reduced-complexity carbon cycle climate model MAGICC6. Projected ??best-estimate?? global-mean surface temperature increases (using inter alia a climate sensitivity of 3°C) range from 1.5°C by 2100 for the lowest of the four RCPs, called both RCP3-PD and RCP2.6, to 4.5°C for the highest one, RCP8.5, relative to pre-industrial levels. Beyond 2100, we present the ECPs that are simple extensions of the RCPs, based on the assumption of either smoothly stabilizing concentrations or constant emissions: For example, the lower RCP2.6 pathway represents a strong mitigation scenario and is extended by assuming constant emissions after 2100 (including net negative CO₂ emissions), leading to CO₂ concentrations returning to 360 ppm by 2300. We also present the GHG concentrations for one supplementary extension, which illustrates the stringent emissions implications of attempting to go back to ECP4.5 concentration levels by 2250 after emissions during the 21^st century followed the higher RCP6 scenario. Corresponding radiative forcing values are presented for the RCP and ECPs.  相似文献