美国全球变化研究现状

美国的全球变化研究主要由美国全球变化研究计划（ＵＳＧＣＲＰ）支持,重点资助季节—年际尺度气候变率,十年—百年尺度的气候变化,臭氧、ＵＶ辐射以及大气化学的变化,土地利用以及陆地、海洋生态系统的变化等４个领域。当前,水汽与云仍是全球变化研究中不确定性较大的一个方面,因而受到关注。关于气候变化的信号检测以及成因分析也是一个研究热点。气候模拟研究是全球变化研究的一个主要方法。卫星资料在全球变化研究中的应用取得了大量成果。近期美国在全球变化研究领域的重点是气候模拟,短期气候预测,十年—百年尺度的气候变化,臭氧、ＵＶ辐射以及大气化学的变化,地表以及陆地、海洋生态系统变化,对全球变化的区域尺度估计,卫星资料的应用,气候变化影响的国家级评估等８个方面。     

南极气候与大气环境研究

南极气候与大气环境研究本研究是国家科技攻关项目（８５－９０５－２－５），周秀骥院士为项目主持人。南极地区，包括南极大陆、亚南极岛屿和环绕南极大陆的南大洋，是全球大气研究计划（ＧＡＲＰ）、世界气候研究计划（ＷＣＲＰ）及国际岩石圈－生物圈计划（ＩＧＢＰ）...     

CMIP6年代际气候预测计划（DCPP）概况与评述

年代际气候预测计划（DCPP）是第六次国际耦合模式比较计划（CMIP6）的子计划之一,其目标是利用多模式开展气候系统年代际预测、可预测性和变率机制研究。DCPP设计了3组试验,即年代际回报试验、预报试验以及理解年代际变率机制和可预测性的敏感性试验。目前有21个模式拟参与DCPP计划,其中包括5个来自中国的模式。DCPP将推动解决气候系统从年际到年代际尺度预测相关的多项科学问题,评估当前气候预测系统预报技巧,挖掘潜在可预报性,研究长时间尺度气候变率形成机制,提供对科学和社会有用的预测产品。     

气候变化的科学—IPCC（1995）评估报告为决策者写的总结

气候变化是当前各国政府和人民普遍关心的热点问题，为了加强在这一领域的国际合作，联合国世界气象组织（ＷＭＯ）和环境规划署（ＵＮＥＰ）于１９８８年联合建立了政府间气候变化专门委员会（ＩＰＣＣ）。ＩＰＣＣ设立了评价现有的气候变化可用科学资料（第一工作组）、评价气候变化的环境和及经济和社会影响（第二工作组）、制定响应对策（第三工作组）等三个工作组和一个发展中国家参与特别委员会，集中了世界各国有关气候、环境、海洋、能源和生态等各方面权威和著名专家，进行了卓有成效的工作。它于１９９０年完成了对气候问题的第一次全面评估报告（ＩＰＣＣＦｉｒｓｔＡｓｓｅｓｓｍｅｎｔＲｅｐｏｒｔ），并于１９９２年提交了补充报告（１９９２ＩＰＣＣＳｕｐｐｌｅｍｅｎｔ），１９９４年提出了气候变化的辐射强迫和ＩＳ９２排放构想（ＣｌｉｍａｔｅＣｈａｎｇｅ，１９９４）。最近出版的《气候变化１９９５》则是自１９９０年首次评估以来，包含内容最多的有关气候变化科学的评估报告（ＣｌｉｍａｔｅＣｈａｎｇｅ，１９９５）。ＩＰＣＣ报告是经正式“批准”（ａｐｐｒｏｖｅｄ）或被“采纳”（ａｃｃｅｐｔｅｄ）的文件。一个经“批准”的报告，需在有关的ＩＰＣＣ工作组全体会议上逐     

热带海洋全球大气计划的海气耦合响应试验（COARE）

热带海洋全球大气计划的海气耦合响应试验（ＣＯＡＲＥ）Ｊ．Ｓ．Ｇｏｄｆｒｅｙ（澳大利亚）１引言１９９２年１１月－１９９３年２月，在巴布亚新几内亚以东地区进行了热带海洋全球大气计划（ＴＯＧＭ）的海气耦合响应试验（ＣＯＡＲＥ），这是人们已进行的阵容最强的海...     

亚洲的全球变化问题

本文分为三个部分,首先论述本世纪,尤其是近几十年来,全球变化在亚洲的主要表现,然后分析引起亚洲变化的主要驱动因子,特别是与全球气候变化相关的亚洲季风的变化和人类的作用;然后主要依据全球气候模式（ＧＣＭ）的结果评估全球增暖条件下亚洲未来２０～５０年的变化。最后讨论了ＧＣＭ模式在区域尺度模拟和评估上的不确定性,提出应将研究亚洲季风系统中大气圈－生物圈相互作用和亚洲地区土地利用／土地覆盖变化这两个科学问题,列入亚洲地区ＩＧＢＰ的研究,并和全球变化的三大国际科学计划ＩＧＢＰ、ＷＣＲＰ和ＨＤＰ中的一系列核心计划相结合     

NCEP/NCAR再分析计划提供的1958～1997年月平均场介绍

美国国家环境预报中心（ＮＣＥＰ）和国家大气研究中心（ＮＣＡＲ）联合执行的全球大气４０年资料再分析计划采用光盘分发了部分产品。南京气象学院校友ＮＣＥＰ的朱跃建和汪学良博士赠送给南京大气资料服务中心一部分再分析产品光盘。上两期资料通讯综合介绍了多种输出产...     

全球气温与ENSO多年际耦合振荡关系的初步研究

借助于最优分割法和多通道奇异谱分析（MSSA）等方法对全球气候变化背景场阶段性变化及其与ENSO振荡信号的相互关系作了详细的诊断分析。结果表明：（1）全球近百年气温长期变化阶段性明显，各阶段之间的气候变率特征差异较大；（2）全球气温变化背景场的阶段性对ENSO的年际及年代际准周期振荡有较为明显的影响；（3）全球气温与Nino区海温的年际变率存在着准4年和准2年的显著耦合振荡。     

北达科他示踪物试验外场作业计划（1993年方案）

北达科他示踪物试验（ＮＤＴＥ）是１９９３年６至７月间以北达科他州俾斯麦为基地进行的对流风暴联合研究。资料的收集从１９９３年６月２１日开始到７月３０日为止。三架飞机、两部地基多普勒天气雷达和多种其它设备将集中观测雷暴和更小的对流单体以研究冰的形成和演变（包括冰雹发展）；输送和扩散；夹卷，风暴结构，动力学和运动学；大气化学，以及云电现象。本计划称为“示踪物试验”是因为加密使用各种大气示踪物。包括雷达箔条，一种惰性气体示踪物（六氟化硫）、臭氧（Ｏ＿３）和荧光珠。这些示踪物由三架云物理试验飞机播撒且就地同步大量取样，同时用多普勒天气雷达遥测北部大平原对流天气至今最为详细的图片。最终目的是获得对冰雹物理演变的较完整的认识，以便更好地评价用于北达科他州西北部的业务消雹撒播方案，同时也肯定会改进对雷暴知识、预报以及强天气的认识。本课题的主要资金来源是：国家海洋大气局（ＮｏＡＡ）大气影响研究联邦一州合作计划，国家科学基金以及北达科他州政府。并从国家大气研究中心（ＮＣＡＲ）、国家强风暴实验室（ＮＳＳＬ）、国家航空和航天局（ＮＡＳＡ）、国家气象局以及加拿大大气环境局（ＡＥＳ）获得了附加资金、人员和（或）设备。一个类似的计划，北     

我国短期气候预测系统的研究——国家“九五”重中之重项目(1996～2000)

我国短期气候预测系统的研究———国家“九五”重中之重项目（１９９６－２０００）短期气候变化是指月、季和年际时间尺度的气候变率和气候异常。许多气候灾害，如干旱、洪涝、持续性低温冷害、持续性高温（热浪）等，与这种气候变率和气候异常密切相关。根据异常气候型...     

平流层大气动力学及其与对流层大气相互作用的研究:进展与问题

本文综述了近年来关于平流层大气动力学及其与对流层大气相互作用动力过程的研究进展,特别是回顾了近年来关于平流层大气环流和行星波动力学、热带平流层大气波动及其与基本气流相互作用、平流层大气环流变异对对流层环流和气候变异的影响及其动力过程、平流层大气数值模拟以及在全球变暖背景下平流层大气的长期演变趋势预估等的研究进展。最近的研究揭示了大气准定常行星波传播波导的振荡现象、重力波在热带平流层准两年振荡和全球物质输送中的作用、平流层长期的变冷趋势变化、平流层在对流层天气和气候变化中的作用等现象,表明了平流层大气动力学研究的重要性。平流层大气动力学的深入研究,以及对数值模式中平流层模拟性能的提高,最终都会推动整个大气科学和气候变化研究的进一步发展。     

Climate scenarios for 2010 and 2050 AD Australia and New Zealand

The various bases for making Australian and New Zealand scenarios of climate change at 2010 and 2050 AD are discussed. Atmospheric greenhouse gas increases will cause historically unprecedented warming by 2050 AD, but the likely regional rainfall changes are uncertain. By 2010 AD greenhouse gas climate change should be detectable with a warming relative to the present of 0.5–1.5 °C. At 2050 AD Australian and New Zealand temperatures will be 2–3 °C higher, the frost free season will be longer and the snowline higher. Rainfall changes will be very much determined by regional airflow and storm tracks, and the state of the Southern Oscillation. In order to obtain unproved and more detailed estimates of climate at 2010 and 2050 AD existing climate models need to be improved. For Australia and New Zealand models need to focus on the south west Pacific-Australia region.     

Impact of Climate Change and Variability on Irrigation Requirements: A Global Perspective

Anthropogenic climate change does not only affect water resources but also water demand. Future water and food security will depend, among other factors, on the impact of climate change on water demand for irrigation. Using a recently developed global irrigation model, with a spatial resolution of 0.5° by 0.5°, we present the first global analysis of the impact of climate change and climate variability on irrigation water requirements. We compute how long-term average irrigation requirements might change under the climatic conditions of the 2020s and the 2070s, as provided by two climate models, and relate these changes to the variations in irrigation requirements caused by long-term and interannual climate variability in the 20th century. Two-thirds of the global area equipped for irrigation in 1995 will possibly suffer from increased water requirements, and on up to half of the total area (depending on the measure of variability), the negative impact of climate change is more significant than that of climate variability.     

Climate Variability and Change: Past, Present and Future – An Overview

Prior to the 20th century Northern Hemisphere average surface air temperatures have varied in the order of 0.5 ^°C back to AD 1000. Various climate reconstructions indicate that slow cooling took place until the beginning of the 20th century. Subsequently, global-average surface air temperature increased by about 0.6 °C with the 1990s being the warmest decade on record. The pattern of warming has been greatest over mid-latitude northern continents in the latter part of the century. At the same time the frequency of air frosts has decreased over many land areas, and there has been a drying in the tropics and sub-tropics. The late 20th century changes have been attributed to global warming because of increases in atmospheric greenhouse gas concentrations due to human activities. Underneath these trends is that of decadal scale variability in the Pacific basin at least induced by the Interdecadal Pacific Oscillation (IPO), which causes decadal changes in climate averages. On interannnual timescales El Niño/Southern Oscillation (ENSO) causes much variability throughout many tropical and subtropical regions and some mid-latitude areas. The North Atlantic Oscillation (NAO) provides climate perturbations over Europe and northern Africa. During the course of the 21st century global-average surface temperatures are very likely to increase by 2 to 4.5 ^°C as greenhouse gas concentrations in the atmosphere increase. At the same time there will be changes in precipitation, and climate extremes such as hot days, heavy rainfall and drought are expected to increase in many areas. The combination of global warming, superimposed on decadal climate variability (IPO) and interannual fluctuations (ENSO, NAO) are expected lead to a century of increasing climate variability and change that will be unprecedented in the history of human settlement. Although the changes of the past and present have stressed food and fibre production at times, the 21st century changes will be extremely challenging to agriculture and forestry.     

Increasing prevalence of extreme summer temperatures in the U.S.

Human-caused climate change can affect weather and climate extremes, as well as mean climate properties. Analysis of observations and climate model results shows that previously rare (5th percentile) summertime average temperatures are presently occurring with greatly increased frequency in some regions of the 48 contiguous United States. Broad agreement between observations and a mean of results based upon 16 global climate models suggests that this result is more consistent with the consequences of increasing greenhouse gas concentrations than with the effects of natural climate variability. This conclusion is further supported by a statistical analysis based on resampling of observations and model output. The same climate models project that the prevalence of previously extreme summer temperatures will continue to increase, occurring in well over 50% of summers by mid-century.     

Framing the way to relate climate extremes to climate change

The atmospheric and ocean environment has changed from human activities in ways that affect storms and extreme climate events. The main way climate change is perceived is through changes in extremes because those are outside the bounds of previous weather. The average anthropogenic climate change effect is not negligible, but nor is it large, although a small shift in the mean can lead to very large percentage changes in extremes. Anthropogenic global warming inherently has decadal time scales and can be readily masked by natural variability on short time scales. To the extent that interactions are linear, even places that feature below normal temperatures are still warmer than they otherwise would be. It is when natural variability and climate change develop in the same direction that records get broken. For instance, the rapid transition from El Ni?o prior to May 2010 to La Ni?a by July 2010 along with global warming contributed to the record high sea surface temperatures in the tropical Indian and Atlantic Oceans and in close proximity to places where record flooding subsequently occurred. A commentary is provided on recent climate extremes. The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.     

Climate Change of 4°C Global Warming above Pre-industrial Levels

Using a set of numerical experiments from 39 CMIP5 climate models, we project the emergence time for 4°C global warming with respect to pre-industrial levels and associated climate changes under the RCP8.5 greenhouse gas concentration scenario. Results show that, according to the 39 models, the median year in which 4°C global warming will occur is 2084. Based on the median results of models that project a 4°C global warming by 2100, land areas will generally exhibit stronger warming than the oceans annually and seasonally, and the strongest enhancement occurs in the Arctic, with the exception of the summer season. Change signals for temperature go outside its natural internal variabilities globally, and the signal-to-noise ratio averages 9.6 for the annual mean and ranges from 6.3 to 7.2 for the seasonal mean over the globe, with the greatest values appearing at low latitudes because of low noise. Decreased precipitation generally occurs in the subtropics, whilst increased precipitation mainly appears at high latitudes. The precipitation changes in most of the high latitudes are greater than the background variability, and the global mean signal-to-noise ratio is 0.5 and ranges from 0.2 to 0.4 for the annual and seasonal means, respectively. Attention should be paid to limiting global warming to 1.5°C, in which case temperature and precipitation will experience a far more moderate change than the natural internal variability. Large inter-model disagreement appears at high latitudes for temperature changes and at mid and low latitudes for precipitation changes. Overall, the inter-model consistency is better for temperature than for precipitation.     

Climate Change of 4℃ Global Warming above Pre-industrial Levels

Using a set of numerical experiments from 39 CMIP5 climate models, we project the emergence time for 4?C global warming with respect to pre-industrial levels and associated climate changes under the RCP8.5 greenhouse gas concentration scenario. Results show that, according to the 39 models, the median year in which 4?C global warming will occur is 2084.Based on the median results of models that project a 4?C global warming by 2100, land areas will generally exhibit stronger warming than the oceans annually and seasonally, and the strongest enhancement occurs in the Arctic, with the exception of the summer season. Change signals for temperature go outside its natural internal variabilities globally, and the signal-tonoise ratio averages 9.6 for the annual mean and ranges from 6.3 to 7.2 for the seasonal mean over the globe, with the greatest values appearing at low latitudes because of low noise. Decreased precipitation generally occurs in the subtropics, whilst increased precipitation mainly appears at high latitudes. The precipitation changes in most of the high latitudes are greater than the background variability, and the global mean signal-to-noise ratio is 0.5 and ranges from 0.2 to 0.4 for the annual and seasonal means, respectively. Attention should be paid to limiting global warming to 1.5?C, in which case temperature and precipitation will experience a far more moderate change than the natural internal variability. Large inter-model disagreement appears at high latitudes for temperature changes and at mid and low latitudes for precipitation changes. Overall, the intermodel consistency is better for temperature than for precipitation.     

Bridging science and community knowledge? The complicating role of natural variability in perceptions of climate change

Although the spatial and temporal scales on which climate varies is a prominent aspect of climate research in the natural sciences, its treatment in the social sciences remains relatively underdeveloped. The result is limited understanding of the public's capacity to perceive climate variability as distinct from change, and uncertainty surrounding how and when to best communicate information on variability/change. Ignoring variability in favour of change-focused analyses and language risks significant misrepresentation of public perception and knowledge, and precludes detailed synthesis of data from the social and natural sciences. An example is presented based on a regional comparison of variability-dominated climate observations and change-focused survey data, collected in western Newfoundland (Canada). This region experiences pronounced, slow-varying natural variability, which acted to obscure broader climate trends through the 1980s and 1990s; since the late 1990s, the same variability has amplified apparent change. While survey results confirm residents perceive regional climate change, it is not clear whether respondents distinguish variability from change. This presents uncertainty in the best approach to climate science communication in this region, and raises concern that subsequent variability-driven transient cooling will erode public support for climate action. Parallels are drawn between these regional concerns and similar uncertainty surrounding treatment of variability in discussion of global temperature trends, highlighting variability perception as a significant gap in human dimensions of climate change research.     

Global-Scale Relationships between Climate and the Dengue Fever Vector, Aedes Aegypti

Considerable interest exists inthe potential role climate may play in human healthissues, especially regarding the effect of climatechange on vector-borne disease. The Aedesaegypti mosquito, the principal vector for dengue,considered the most important vector-borne viraldisease in the world, is particularly susceptible toclimate variability and climatic change. Here wepresent a modeling analysis focusing on global-scaleassociations between climate and the development,potential distribution, and population dynamics ofAe. aegypti. We evaluate the model by comparingand contrasting model data with observed mosquitodensities. There is good agreement between theobserved and modeled global distribution of themosquito; however, the model results suggest thepotential for increased latitudinal distributionsduring warmer months. Seasonal fluctuations inmosquito abundance also compare well to observed data. Discrepancies possibly reflect the relatively lowresolution of the climate data and model output andthe inability of the model to account for localmicroclimate effects, especially in coastal areas.Future modeling efforts will involve study ofinterannual variability in mosquito dynamics.