共查询到17条相似文献，搜索用时 156 毫秒
1.
美国国家科学基金会（NSF）是国际上具有重要影响的资助基础科学研究的政府基金机构，对促进美国基础科学研究的发展和保持世界领先地位做出了重要贡献。其对基础研究的资助政策、方向遴选、评审程序、经费分配、管理机制等，形成了一套行之有效的模式，对其它国家的基础研究政府资助机构具有借鉴和示范意义。在分析美国NSF近3年经费状况及其领域分配情况、近5年项目受理与批准情况、近12年项目评议情况的基础上，重点分析了地学学部（GEO）的近期重点资助领域、近3年按照NSF的整体优先领域和战略产出目标的经费分配情况、近10年按科学处的经费分配情况及变化趋势、各科学处2004—2006财政年度经费状况与重点资助领域、近10年项目的资助率与资助强度变化情况等。NSF地学学部是美国政府资助以大学为主的地学基础研究的主要渠道，其经费约占美国政府资助地学基础研究经费的62%。对NSF的基金项目资助战略，特别是对其地学学部项目的资助情况予以全面分析，对我国相关部门的管理工作有重要参考价值和借鉴意义。 相似文献
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21世纪初，美国国家大气研究中心（Nat ionalCenterforAtmosphericResearch，NCAR
）专门组织人员撰写了它将来在研究、设施及教育上的规划报告。该报告围绕什么是要继续的、什么是阶段性的、如何开创新的研究方向、新方向的选择标准等作了阐述。介绍了该规划报告中关于下一个 10年新的研究方向，其中包括NCAR各分支机构之间联合研究的新研究计划，以及模式集成、先进的工具和方法以及将信息技术用于研究和教育等方面的新研究计划，同时还界定了新研究计划的选择标准。 相似文献
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国际地球科学与资源环境科学发展战略分析 总被引：4，自引：5，他引：4
介绍了国际主要地学机构（NASA、USGS、NOAA、NERC、BGS）、主要组织（ICSU、EU、OECD、UNESCO）、国际主要基金机构（NSF、ESF）21世纪初10～20年有关地球科学与资源环境科学的研究与发展战略的目标、研究计划、主要研究内容与优先研究领域。这些机构与组织的地学与资源环境科学发展战略，反映了国际上地球科学与资源环境科学的研究重点和发展趋势，对把握国际地球科学与资源环境科学发展方向、明确我国地球科学与资源环境科学的战略重点和优先领域具有重要的参考价值。同时，依据美国科学信息研究所（ISI）的基本科学指标数据库（ESI），分析了过去20年国际地学（geosciences）、环境／生态学（environment／ec ology）领域著名科学家的国别和机构分布状况，分析了国际地学、环境／生态学过去10年成果产出最多、论文被引频次最多、篇均被引频次最高的前10个研究机构，反映了过去10年国际地学、环境／生态学研究的影响力。最后，简要分析了国际地球科学与资源环境科学的优先研究领域与主要特点。 相似文献
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全球气候变化通过改变环境、自然资源、经济等诸多方面对美国产生广泛的影响。美国全球变化研究计划（USGCRP）主要为美国乃至全世界提供帮助来理解和预测气候变化、环境响应机制等相关的科学知识,预测气候变化或气候变异引起其他的变化,为应对气候变化的相关政策和风险管理提供理论依据。研究主要包括理论基础研究、综合观测研究、模型预测研究,为决策者提供相关产品等。2011年年末NSF如期对USGCRP进行了完善,并率先发展和制定了USGCRP战略新计划。从NSF对USGCRP的资助力度来看,2012年度预算比2011年预算增加了33％,即106．05百万美元,2012年度的重点研究领域为： 相似文献
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美国国家生态观测站网络(NEON)--概念、设计和进展 总被引：4，自引：2，他引：2
美国国家生态观测站网络（NEON）是一个以研究区域至大陆尺度重要环境问题的国家网络,它是由美国国家科学基金会（NSF）于2000年提出建立的。NEON的目标是通过网络式的观测、试验、研究和综合分析,阐明环境变化的成因和后果,预测环境变化的趋势并提出相应的对策。它是一个由17个区域网络组成的国家生态学研究和环境教育平台。该网络的建成,将为促进生态学的发展、人才培养以及保障美国的生物和生态安全发挥重要作用。由美国国家科学院国家研究委员会的地球与生命研究部任命的专家委员会于2003—2004年对NEON的原设计和建设方案进行了评估,充分肯定了建立NEON的必要性,但同时对原设计和建设方案提出了一些重大修改意见。新的方案建议NEON应重点关注生物多样性、物种组成与生态系统功能、生物地球化学循环的生态学影响、气候变化的生态学内涵、传染病的生态学和演化、入侵种以及土地利用和栖息地的丧失这6个美国国家层次当前所面临的最严峻的环境挑战。未来的NEON将由研究这些问题所设置的6个国家网络组成。深入研究NEON的概念、设计方案和实施计划,对于我国国家生态观测和研究网络的建设具有重要的参考意义。 相似文献
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美国国家大气研究中心优先研究领域新特点 总被引：1，自引：0，他引：1
美国国家大气研究中心于2005年11月提出了新的战略计划。该计划突出的新特点在于无论科学研究活动还是教育、观测设施等方面的战略目标和优先领域,都是以地球系统研究为中心。如在科学研究方面的战略目标确定为：认识地球系统的作用、准确预报地球系统的演变。相应的优先研究领域则为：研究和了解地球和太阳的自然变率;地球系统各分量的相互作用;地球系统预报;人类活动与地球系统的演变等。鉴于NCAR在国际大气科学界的地位,这种以地球系统为中心的优先研究领域对我国大气科学及地球科学研究有一定的借鉴意义,同时也将促使大气科学工作者摆脱传统天气、气候概念的束缚,站在更高的高度来科学审视学科的发展。 相似文献
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P. L. S. Rao U. C. Mohanty P. V. S. Raju M. A. Arain 《Journal of Earth System Science》2004,113(3):281-298
The study delineates the vorticity and angular momentum balances of Asian summer monsoon during the evolution and established
phases. It also elucidates the differences between these balances in the National Centre for Environmental Prediction/National
Centre for Atmospheric Research (NCEP/NCAR) reanalysis and the National Centre for Medium Range Weather Forecasts (NCMRWF)
analysis fields. The NCEP/NCAR reanalysis for a 40 year period (1958-97) and the NCMRWF analysis for a three year (1994-96)
period are made use of for the purpose. The time mean summer monsoon circulation is bifurcated into stable mean and transient
eddy components and the mean component is elucidated.
The generation of vorticity due to stretching of isobars balances most of the vorticity transported out of the monsoon domain
during the evolution period. However, during the established period, the transportation by the relative and planetary vorticity
components exceeds the generation due to stretching. The effective balancing mechanism is provided by vorticity generation
due to sub-grid scale processes. The flux convergence of omega and relative momenta over the monsoon domain is effectively
balanced by pressure torque during the evolution and established phases. Nevertheless, the balance is stronger during the
established period due to the increase in the strength of circulation.
Both the NCMRWF and NCEP fields indicate the mean features related to vorticity and angular momentum budgets realistically.
Apart from the oceanic bias (strong circulation over oceans rather than continents), the summer monsoon circulation indicated
by the NCEP is feeble compared to NCMRWF. The significant terms in the large-scale budgets of vorticity and angular momentum
enunciate this aspect 相似文献
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Much progress has been made in the area of tropical cyclone prediction using high-resolution mesoscale models based on community models developed at National Centers for Environmental Predication (NCEP) and National Center for Atmospheric Research (NCAR). While most of these model research and development activities are focused on predicting hurricanes in the Atlantic and Eastern Pacific domains, there has been much interest in using these models for tropical cyclone prediction in the North Indian Ocean region, particularly for Bay of Bengal storms that are known historically causing severe damage to life and property. In this study, the advanced operational hurricane modeling system developed at NCEP, known as the Hurricane Weather Research and Forecast (HWRF) model, is used to simulate two recent Bay of Bengal tropical cyclones??Nargis of November 2007 and Sidr of April 2008. The advanced NCEP operational vortex initialization procedure is adapted for simulating these Bay of Bengal tropical cyclones. Two additional regional models, the NCAR Advanced Research WRF and NCAR/Penn State University Mesoscale Model version 5 (MM5) are also used in simulating these storms. Results from these experiments highlight the superior performance of HWRF model over other models in predicting the Bay of Bengal cyclones. These results also suggest the need for a sophisticated vortex initialization procedure in conjunction with a model designed exclusively for tropical cyclone prediction for operational considerations. 相似文献
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In this article, the interannual variability of certain dynamic and thermodynamic characteristics of various sectors in the
Asian summer monsoon domain was examined during the onset phase over the south Indian peninsula (Kerala Coast). Daily average
(0000 and 1200 UTC) reanalysis data sets of the National Centre for Environmental Prediction/National Centre for Atmospheric
Research (NCEP/NCAR) for the period 1948–1999 were used. Based on 52 years onset date of the Indian summer monsoon, we categorized
the pre-onset, onset, and post-onset periods (each an average of 5 days) to investigate the interannual variability of significant
budget terms over the Arabian Sea, Bay of Bengal, and the Indian peninsula. A higher difference was noticed in low-level kinetic
energy (850 hPa) and the vertically integrated generation of kinetic energy over the Arabian Sea from the pre-onset, onset,
and post-onset periods. Also, significant changes were noticed in the net tropospheric moisture and diabatic heating over
the Arabian Sea and Indian peninsula from the pre-onset to the post-onset period. It appears that attaining the magnitude
of 40 m2 s−2 and then a sharp rise in kinetic energy at 850 hPa is an appropriate time to declare the onset of the summer monsoon over
India. In addition to a sufficient level of net tropospheric moisture (40 mm), a minimum strength of low-level flow is needed
to trigger convective activity over the Arabian Sea and the Bay of Bengal. An attempt was also made to develop a location-specific
prediction of onset dates of the summer monsoon over India based on energetics and basic meteorological parameters using multivariate
statistical techniques. The regression technique was developed with the data of May and June for 42 years (1948–1989) and
validated with 10 years NCEP reanalysis from 1990 to 1999. It was found that the predicted onset dates from the regression
model are fairly in agreement with the observed onset dates obtained from the Indian Meteorology Department. 相似文献
14.
利用美国国家大气研究中心(NCAR)的CCSM2全球气候系统模式以及重建的古地理资料研究了晚白垩世(80Ma)东亚的古气候特征。模拟结果表明:80Ma时期东亚地区大范围盛行的风向和气压系统随季节有显著变化,由此可以推断东亚地区当时是存在季风环流的。与现代气候比较,白垩纪时期大陆上空的大气环流系统经向特征更明显,这种特征可能与当时欧亚大陆东西向跨度较小有关。此外,在当时偏暖的背景下,东亚冬季风和夏季风呈现出一致的变化特征,即冬季风和夏季风都比现代强。年平均降水的分布型和现代的情况比较相似,降水最大值出现在10°S～10°N的赤道辐合带中,与西太平洋相邻的大陆东岸降水也较多,其中心超过1200mm,而在中纬度的内陆地区降水则稀少。虽然与现代情况相似,80Ma在30°N附近的西太平洋上也为多雨带,然而在东亚陆地上没有多雨带,这说明了青藏高原隆升在现代东亚夏季梅雨形成中的重要性。此外,模拟的80Ma时期东亚地区气候要比现代温暖,相同纬度的表面气温要高2℃以上,模拟的温度与地质证据估计的温度比较接近。 相似文献
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Ananda K. Das U. C. Mohanty Someshwar Das M. Manual S. R. Kalsi 《Journal of Earth System Science》2003,112(2):165-184
The skill and efficiency of a numerical model mostly varies with the quality of initial values, accuracy on parameterization
of physical processes and horizontal and vertical resolution of the model. Commonly used low-resolution reanalyses are hardly
able to capture the prominent features associated with organized convective processes in a monsoon depression. The objective
is to prepare improved high-resolution analysis by the use of MM5 modelling system developed by the Pennsylvania State University/National
Center for Atmospheric Research (PSU/NCAR). It requires the objective comparison of high and low-resolution analysis datasets
in assessing the specific convective features of a monsoon depression. For this purpose, reanalysis datasets of NCAR/NCEP
(National Center for Atmospheric Research/National Centers for Environmental Prediction) at a horizontal resolution of 2.5‡
(latitude/longitude) have been used as first guess in the objective analysis scheme. The additional asynoptic datasets obtained
during BOBMEX-99 are utilized within the assimilation process. Cloud Motion Wind (CMW) data of METEOSAT satellite and SSM/I
surface wind data are included for the improvement of derived analysis. The multiquadric (MQD) interpolation technique is
selected and applied for meteorological objective analysis at a horizontal resolution of 30 km. After a successful inclusion
of additional data, the resulting reanalysis is able to produce the structure of convective organization as well as prominent
synoptic features associated with monsoon depression. Comparison and error verifications have been done with the help of available
upper-air station data. The objective verification reveals the efficiency of the analysis scheme. 相似文献
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In this study, the simulation of an extreme weather event like heavy rainfall over Mumbai (India) on July 26, 2005 has been
attempted with different horizontal resolutions using the Advanced Research Weather Research Forecast model version 2.0.1
developed at the National Center for Atmospheric Research (NCAR), USA. The study uses the Betts–Miller–Janjic (BMJ) and the
Grell–Devenyi ensemble (GDE) cumulus parameterization schemes in single and nested domain configurations. The model performance
was evaluated by examining the different predicted parameters like upper and lower level circulations, moisture, temperature,
and rainfall. The large-scale circulation features, moisture, and temperature were compared with the National Centers for
Environmental Prediction analyses. The rainfall prediction was assessed quantitatively by comparing rainfall from the Tropical
Rainfall Measuring Mission products and the observed station values reported in the Indian Daily Weather Reports from India
Meteorological Department (IMD). The quantitative validation of the simulated rainfall was done by calculating the categorical
skill scores like frequency bias, threat scores (TS), and equitable threat scores (ETS). It is found that in all simulations,
both in single and nested domains, the GDE scheme has outperformed the BMJ scheme for the simulation of rainfall for this
specific event. 相似文献
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美国长期生态学研究网络的战略规划——走向综合科学的未来 总被引：2，自引：0，他引：2
从2004年11月起至今,美国长期生态学研究网络在美国国家科学基金会的资助下,为未来(几)十年的综合和网络层面研究进行了战略规划.规划的最终目标是形成一个新的长期生态学研究(LTER)网络层面科学计划,并通过1个科学课题组、7个网络科学工作组和一系列研讨会来进行.在制定和完善科学计划的过程中,规划行动获得了LTER网络层面科学的跨学科问题、概念框架、基本科学问题、社会与环境综合科学动议、网络计算机基础设施的战略规划、教育与宣传战略规划等重大科学产出.规划的意义在于它告诉了怎样走向LTER的未来--网络层面综合科学,因而有利于LTER及长期生态研究的发展,并可为CERN等其他长期生态学研究网络的规划与发展提供启示. 相似文献