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1.
By DANIEL ROSENFELD JIM PETERSON ARON GINGIS 《Tellus. Series B, Chemical and physical meteorology》2009,61(4):694-700
Rosenfeld (2000, hereafter R00), in applying new satellite methodology to analyse case studies in Southeastern Australia and elsewhere, provided evidence that urban and industrial air pollution can suppress precipitation from shallow clouds. He concluded that 'Air pollution must be an important factor in determining the precipitation amounts in the Snowy Mountains'. These satellite observations were the impetus for our proposed detailed follow-on research program to further validate and quantify these inferences, publicly offered in Rosenfeld et al. (2006, hereafter R06) and repeated here, thereby recognizing the remaining large uncertainties. In response, Ayers (2009, hereafter A09) attempts to deny the significance and validity of the observations of R00. His scientific arguments are refuted here. Furthermore, A09 wrote erroneously that 'a hypothesis that air pollution in the form of small particles has caused a secular decrease in precipitation over SE Australia was advanced by Rosenfeld (2000) , who concluded that the hypothesis was proven.' But R00 did not make such a claim, although this is a viable hypothesis that warrants testing (R06). In fact, R00 wrote: 'trend analyses of snow, winter temperature, and total winter rainfall for the period 1910–1991 showed statistically insignificant decreases… ( Duus, 1992 )'. 相似文献
2.
Levin et al. (referred here as LHA) made a sweeping conclusion that cloud seeding has been ineffective in Israel. They claimed that the results of the Israel-2 experiment could be fully ascribed to synoptic bias. However, the cross over analysis of Israel-2 has shown the same already in 1990 by Gabriel and Rosenfeld. While LHA only showed differences in the 850 hPa winds being stronger in the north seeded days of Israeli-2, Rosenfeld and Farbstein had already shown quantitatively in 1992 that this synoptic bias explains less than half of the indicated seeding effect in the north. Furthermore, accepting that a cross over design protects against synoptic bias means that the highly positive and statistically significant indicated seeding effect in Israeli-1, which was based on a cross-over design, cannot be explained by such synoptic bias. Instead, LHA completely ignored the Israeli-1 experiment.LHA's evaluation of the operational seeding used implied assumption that amounted to historical comparisons that have already been shown to be invalid, especially for the Israeli situation due to the decreasing trend of target–control ratio, especially over the eastern upper Galilee. For all of the above reasons, the conclusion of LHA that cloud seeding is ineffective in Israel is not supported by the data.Given the uncertainties, both physical and statistical, the Israeli water authority has embarked on the Israeli-4 randomized cloud seeding experiment, which is aimed at testing the hypothesis that cloud seeding might be affecting mainly the precipitation in the orographic clouds developing over the hills in the catchment of the Jordan River. 相似文献
3.
为进一步促进土地利用和土地覆盖变化（Land-Use and Land-Cover Change,LULCC）以及土地管理对气候影响的理解,第六次国际耦合模式比较计划（CMIP6）设立了土地利用模式比较计划（LUMIP）。该计划主要包括两个阶段的试验设计：第一阶段涉及理想的毁林情景耦合试验和陆面模式模拟试验,旨在促进LULCC对气候影响过程的理解,并量化模式对LULCC的敏感性。第二阶段的试验重点关注土地利用变化的历史影响,以及未来土地管理决策在减缓气候变化方面的潜力。本文概述了其科学背景、试验设计和方案、参与模式情况等,并简评了该计划的研究意义和特色,以期读者迅速了解其相关的研究要点和发展方向。 相似文献
4.
Patrick Huntjens Louis Lebel Claudia Pahl-Wostl Jeff Camkin Roland Schulze Nicole Kranz 《Global Environmental Change》2012,22(1):67-81
This paper provides an evidence-based contribution to understanding processes of climate change adaptation in water governance systems in the Netherlands, Australia and South Africa. It builds upon the work of Ostrom on institutional design principles for local common pool resources systems. We argue that for dealing with complexities and uncertainties related to climate change impacts (e.g. increased frequency and intensity of floods or droughts) additional or adjusted institutional design propositions are necessary that facilitate learning processes. This is especially the case for dealing with complex, cross-boundary and large-scale resource systems, such as river basins and delta areas in the Netherlands and South Africa or groundwater systems in Western Australia. In this paper we provide empirical support for a set of eight refined and extended institutional design propositions for the governance of adaptation to climate change in the water sector. Together they capture structural, agency and learning dimensions of the adaptation challenge and they provide a strong initial framework to explore key institutional issues in the governance of adaptation to climate change. These institutional design propositions support a “management as learning” approach to dealing with complexity and uncertainty. They do not specify blueprints, but encourage adaptation tuned to the specific features of local geography, ecology, economies and cultures. 相似文献
5.
This is the first paper to report a detailed comparison between ground based measurements of cloud enhanced ultraviolet (UV) radiation at sites located in both hemispheres. The measurements were undertaken at a Northern Hemisphere site (at the campus of the University of Girona in Spain) and a Southern Hemisphere site (campus of the University of Southern Queensland, Toowoomba, Australia). These sites were chosen as they have both simultaneous sky camera and solar radiation (including UV) measurement campaigns operating for at least 5 years over the same time period. Although hemispheric comparisons of UV radiation are not new, this paper focuses on a study of enhancements, including a comparison of the frequency of occurrence and associated cloud types, at the locations with differing climatology. It is found that although there are commonalities between the sites, such as the correlation of the frequency of enhancements with larger solar zenith angle (SZA) both at Girona and Toowoomba, there are differences too, e.g. the frequency of occurrence of the enhancements, and the type of clouds that produce most enhancements (cirrus at Girona, cumulus at Toowoomba). It is suggested that this is due to the differences in latitude coupled with a large amount of Cirriform cloud, especially corresponding to large SZA, at Girona. Possible explanations for this major difference were examined, with the most likely hypothesis relating to multiple scattering due to Cirriform cloud and the subsequent effect on UV radiation on a horizontal surface at large SZA. 相似文献
6.
This paper draws on research conducted with Aboriginal land managers across Northern Australia to show how and why payments for ecosystem service (PES) schemes should be framed around Indigenous rights to and relationships with their traditional estates. PES schemes offer opportunities to recognize and support Aboriginal communities' land and sea management knowledge and practices, and there is strong evidence that Indigenous communities are seeking to engage with such schemes. We focus on Aboriginal savanna landscape management, particularly traditional burning practices, to extend the ecosystem services framework to recognize Indigenous values and interactions with their lands as a critical service for Indigenous well-being. Drawing on case-study analysis of PES projects negotiated to support Aboriginal fire management programs across Northern Australia, we show how cultural ecosystem services can be applied to represent the active, dynamic and often interdependent relationships inherent in Indigenous human-environment relationships. 相似文献
7.
气候变化的检测归因是历次IPCC评估报告的重要组成部分。检测归因的目标是检测并量化由外强迫引起的变化,识别人为和自然强迫对气候变化的相对贡献。有助于全面评估气候系统是如何受人类活动影响的,所得结论对未来气候变化预估的信度而言至关重要。检测归因模式比较计划(DAMIP)是第六次国际耦合模式比较计划(CMIP6)的一个子计划,共包含3个级别、多达14组不同强迫驱动下的试验。文中概述其科学背景、试验设计、参与模式情况,并评述该计划的意义、期待的产出以及中国的机遇和贡献,以期使读者迅速了解相关要点和进展,为利用这些模式模拟试验数据开展检测归因研究提供必要的参考。 相似文献
8.
Neural network based daily precipitation generator (NNGEN-P) 总被引：1，自引：0，他引：1
Jean-Philippe Boulanger Fernando Martinez Olga Penalba Enrique Carlos Segura 《Climate Dynamics》2007,28(2-3):307-324
Daily weather generators are used in many applications and risk analyses. The present paper explores the potential of neural network architectures to design daily weather generator models. Focusing this first paper on precipitation, we design a collection of neural networks (multi-layer perceptrons in the present case), which are trained so as to approximate the empirical cumulative distribution (CDF) function for the occurrence of wet and dry spells and for the precipitation amounts. This approach contributes to correct some of the biases of the usual two-step weather generator models. As compared to a rainfall occurrence Markov model, NNGEN-P represents fairly well the mean and standard deviation of the number of wet days per month, and it significantly improves the simulation of the longest dry and wet periods. Then, we compared NNGEN-P to three parametric distribution functions usually applied to fit rainfall cumulative distribution functions (Gamma, Weibull and double-exponential). A data set of 19 Argentine stations was used. Also, data corresponding to stations in the United States, in Europe and in the Tropics were included to confirm the results. One of the advantages of NNGEN-P is that it is non-parametric. Unlike other parametric function, which adapt to certain types of climate regimes, NNGEN-P is fully adaptive to the observed cumulative distribution functions, which, on some occasions, may present complex shapes. On-going works will soon produce an extended version of NNGEN to temperature and radiation. 相似文献
9.
针对目前测定生活饮用水中的苯并(a)芘(简称Bap),采用的是国家标准《生活饮用水标准检验法》GB5750-85中的纸层析—荧光分光光度法,其准确度、精密度很难令人满意,提出了使用高效液相色谱法来定量检测城市自来水中的Bap。实验结果表明:该方法快速、准确,具有优异的重现性,线性范围为4.0～30.0 ng/L,线性系数为0.9999。日内(5 h)、日间(5 d)精密度均小于4.0%(n=5),Bap的回收率为89.0%～93.4%。由于Bap见光极容易分解,影响测定结果,因此采样后应尽快分析。 相似文献
10.
CMIP6情景模式比较计划（ScenarioMIP）概况与评述 总被引：6，自引：0，他引：6
情景模式比较计划（ScenarioMIP）是第六次国际耦合模式比较计划（CMIP6）最重要的子计划之一。该子计划基于不同共享社会经济路径可能发生的能源结构所产生的人为排放及土地利用变化,设计了一系列新的情景预估试验,为未来气候变化机理研究以及气候变化减缓和适应研究提供关键的数据支持。文中将重点介绍ScenarioMIP的试验设计及模式参与情况,并对其应用前景加以讨论和展望。 相似文献
11.
In this paper we assess the impact of climate change, at a micro-scale for a selection of four sites in New Zealand and Australia. These sites are representative of the key destination ski regions. In contrast to previous work, our work will for the first time, allow for a direct comparison between these two countries and enable both an estimate of the absolute impacts at a given site, as well as the relative impacts between the two countries. This direct comparison is possible because we have used exactly the same snow model, the same 3 global climate models (GCMs) and the same techniques to calibrate the model for all locations. We consider the changes in natural snow at these locations for the 2030–2049 and 2080–2099 time periods, for one mid-range emissions scenario (A1B). This future scenario is compared to simulations of current, 1980–1999, snow at these locations. We did not consider the snowmaking or economic components of the ski industry vulnerability, only the modelled changes in the natural snow component. At our New Zealand sites, our model indicates that by the 2040s there will be on average between 90 % and 102 % of the current maximum snow depth (on 31 August) and by the 2090s this will be on average reduced to between 46 % and 74 %. In Australia, our models estimates that by the 2040s there will be on average between 57 % and 78 % of the current maximum snow depth and by the 2090s this will be on average further reduced to between 21 % and 29 %. In terms of days with snowdepths equal to or exceeding a ski industry useable levels of 0.30 m, at our lowest elevation, and most sensitive sites, we observe a change from 125 days (current) to 99–126 (2040s) and 52–110 (2090s) in New Zealand. In Australia, a reduction from 94 to 155 days (current) to 81–114 (2040s) and 0–75 (2090s) is observed. In each case the changes are highly depended on the GCM used to drive the climate change scenario. While the absolute changes will have direct impacts at each location, so too will the relative changes with respect to future potential Australia–New Zealand tourism flows, and beyond. Our study provides an approach by which other regions or countries with climate sensitive tourism enterprises could assess the relative impacts and therefore the potential wider ranging ramifications with respect to destination attractiveness. 相似文献
12.
高分辨率模式比较计划(HighResMIP)是第六次国际耦合模式比较计划(CMIP6)的新增计划,旨在研究水平分辨率提高后对气候模式模拟性能的改进,并借助多模式集合的方法降低模拟的不确定性。中国有5个模式团队在CMIP6 GitHub上注册参加HighResMIP。文中对HighResMIP的科学背景、试验设计和参与模式等方面进行了简要介绍,为需要了解该计划的科研人员提供参考。 相似文献
13.
This study investigates the connections between climate fluctuations and sardine and anchovy production in the NW Mediterranean, taking the Western Mediterranean Oscillation index (WeMOi) as an indicator of climate variability. The basic working hypothesis is that sardine and anchovy productivity is influenced by the WeMOi, a proxy for the local environmental conditions such as sea surface temperature (SST) and river runoff. Sardine and anchovy landings (1974–2009) in the Catalan Coast and landings per unit of effort (LPUE) were used as proxy for recruitment. The results demonstrated a clear link between climate fluctuations and sardine and anchovy production. Positive WeMOi values were significantly correlated with low SST, high river runoff and high LPUE, that is, with better-than-average recruitment of sardine and anchovy. Conversely, negative WeMOi values were associated with high SST, low river runoff and low LPUE. During the negative WeMOi phases (such as that at the end of the analyzed period), environmental conditions are unfavourable for the overall biological productivity in the NW Mediterranean and would decrease the survival, growth, condition and reproduction of sardine and anchovy during their life cycle. Despite the evidences on the appropriateness of the NAOi as an indicator of the climate in Europe and its impact on some biological variables, we suggest that using a regional index, such as the WeMOi, can provide a more accurate representation of the environmental conditions affecting small pelagic fish production in the NW Mediterranean. 相似文献
14.
配额拍卖机制在碳市场中具有重要作用。文中在综述配额拍卖机制研究进展的基础上,重点回顾拍卖机制在欧盟、美国加州和澳大利亚等具有代表性的国际碳市场中的应用情况,结合国内试点碳市场的运行情况,分析不同地区碳市场中拍卖机制的效果。研究认为,国际碳市场拍卖机制设计较为完善,在实际应用中效果良好,起到了增强市场流动性的作用,国内各试点碳市场拍卖机制仍处于探索阶段。文中从拍卖机制的要素设计、平台建设、所得资金管理等方面对全国统一碳市场配额拍卖机制设计提出建议,为全国碳市场中拍卖机制的建设提供参考。 相似文献
15.
Statistical Relationship Between UVB(280-320nm) and Broadband Solar Radiation(295-2800nm) at a Subtropical Location(Qena,Egypt) 
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下载免费PDF全文 The present study quantifies the relationship between ultraviolet-B(UVB) and broadband solar radiation(G) at Qena,Egypt.Data from 10-year hourly integrated totals for both UVB and G on a horizontal surface were used to determine the best fit between the two radiation types.On the basis of the correlation of determination(r2),a second-order polynomial was determined to provide the best fit.For the purpose of developing an empirical model to estimate UVB,all of the cases of UVB and G from a nine-year study from 2001 to 2009 were introduced.Monthly and seasonal empirical models,as well as a general expression,were established for UVB as a function of G.The values of r2 ranged from 0.90 to 0.97.By using a new dataset of G,the estimated and the corresponding measured values of UVB were determined to be in good agreement whereby the values of r2 between the two ranged from 0.91 to 0.98.In addition,the significance and performance of the regression forms were evaluated with the aid of several statistical analysis procedures.The values of the index of modeling(d) and coefficient of modeling efficiency(ME) were close to one.Moreover,the values of RMSE,mean bias error(MBE),and mean absolute error(MAE) were lower than the experimental errors.On the basis of this analysis,it has been determined that the suggested regression forms can be used to estimate UVB when it difficult to obtain measurements or when measurements are available only for limited periods at the studied region. 相似文献
16.
Turbulence characteristics of convectively mixed layers over rugged and homogenous terrain are presented, and their differences are sought. The data used in the study were obtained from aircraftborne instruments. Apart from statistics related to the mixing ratio q, there does not seem to be a marked difference between the two sets of data. This lack of difference is attributed to the degree of ruggedness of the terrain and the dominant wind direction. The behaviour of some statistics related to q is attributed to the entrainment effect of the unstable layer of the moist, cool air above the mixed layer.This work was initiated and a large part of it was completed while all three authors were with CSIRO (Commonwealth Scientific Industrial Research Organisation), Australia.Formerly at: Division of Atmospheric Research, CSIRO, Epping, NSW, Australia.Formerly at: Division of Mathematics and Statistics, CSIRO, Lindfield, NSW, Australia. 相似文献
17.
Robert J. Davy Milton J. Woods Christopher J. Russell Peter A. Coppin 《Boundary-Layer Meteorology》2010,135(1):161-175
Measurements show that on numerous occasions the low-level wind is highly variable across a large portion of south-eastern Australia. Under such conditions the risk of a large rapid change in total wind power is increased. While variability tends to increase with mean wind speed, a large component of wind variability is not explained by wind speed alone. In this work, reanalysis fields from the US National Centers for Environmental Prediction (NCEP) are statistically downscaled to model wind variability at a coastal location in Victoria, Australia. In order to reduce the dimensionality of the problem, the NCEP fields are each decomposed using empirical orthogonal function (EOF) techniques. The downscaling technique is applied to two periods in the seasonal cycle, namely (i) winter to early spring, and (ii) summer. In each case, data representing 2 years are used to form a model that is then validated using independent data from another year. The EOFs that best predict wind variability are examined. To allow for non-linearity and complex interaction between variables, all empirical models are built using random forests. Quantitatively, the model compares favourably with a simple regression of wind variability against wind speed, as well as multiple linear regression models. 相似文献
18.
Application of Artificial Neural Networks to Rainfall
Forecasting in Queensland, Australia 总被引：1，自引：0，他引：1
In this study,the application of artificial intelligence to monthly and seasonal rainfall forecasting in Queensland,Australia,was assessed by inputting recognized climate indices,monthly historical rainfall data,and atmospheric temperatures into a prototype stand-alone,dynamic,recurrent,time-delay,artificial neural network.Outputs,as monthly rainfall forecasts 3 months in advance for the period 1993 to 2009,were compared with observed rainfall data using time-series plots,root mean squared error(RMSE),and Pearson correlation coefficients.A comparison of RMSE values with forecasts generated by the Australian Bureau of Meteorology’s Predictive Ocean Atmosphere Model for Australia(POAMA)-1.5 general circulation model(GCM) indicated that the prototype achieved a lower RMSE for 16 of the 17 sites compared.The application of artificial neural networks to rainfall forecasting was reviewed.The prototype design is considered preliminary,with potential for significant improvement such as inclusion of output from GCMs and experimentation with other input attributes. 相似文献
19.
The durability of concrete is determined largely by its deterioration over time which is affected by the environment. Climate change may alter this environment, causing an acceleration of deterioration processes that will affect the safety and serviceability of concrete infrastructure in Australia, U.S., Europe, China and elsewhere. This investigation of concrete deterioration under changing climate in Australia uses Monte-Carlo simulation of results from General Circulation Models (GCMs) and considers high greenhouse gas emission scenarios representing the A1FI schemes of the IPCC. We present the implications of climate change for the durability of concrete structures, in terms of changes in probability of reinforcement corrosion initiation and corrosion induced damage at a given calendar year between 2000 and 2100 across Australia. Since the main driver to increased concrete deterioration is CO2 concentration and temperature, then increases in damage risks observed in Australia are likely to be observed in other concrete infrastructure internationally. The impact of climate change on the deterioration cannot be ignored, but can be addressed by new approaches in design. Existing concrete structures, for which design has not considered the effects of changing climate may deteriorate more rapidly than originally planned. 相似文献
20.
高砷煤开采和利用中砷的环境影响分析 总被引：2，自引：0，他引：2
概述了我国煤的分级标准和国内外高砷煤开发利用的现状,并根据某公司拟开采的高砷煤矿为例,对高砷煤开采和利用过程中各个环节的环境影响进行了分析。结果表明:高砷煤中虽然含砷较高,但只要采取适当的技术措施,在高砷煤开发和利用过程砷污染可得到有效控制,高砷煤矿是可以安全开采和使用的。但高砷煤必须作为工业用煤(电厂用煤),不允许用于民用。 相似文献