黑龙江省粮食产量结构与影响产量的气象因子分析

通过黑龙江省1949～2006年粮食产量结构分析及近30年的粮食单产与5～9月气象要素相关分析,得出黑龙江省粮食总产的波动主要取决于粮食作物平均单产波动及作物种植结构的调整.1949年以来,在粮食作物中,玉米和大豆所占比例变化不大,水稻呈逐年增加的趋势,春小麦在20世纪90年代以前呈逐步增加的趋势,而90年代以后则急速下降;水稻的单产最高,其次是玉米,再次是春小麦,大豆单产最低;从单产的增减趋势来看,各种粮食作物单产基本呈逐步增长的趋势.影响黑龙江省粮食产量丰歉的主要气象因子为6月平均温度、9月降水量、5月和6月日照时数.     

Effects of climate on numbers of northern prairie wetlands

The amount of water held in individual wetland basins depends not only on local climate patterns but also on groundwater flow regime, soil permeability, and basin size. Most wetland basins in the northern prairies hold water in some years and are dry in others. To assess the potential effect of climate change on the number of wetland basins holding water in a given year, one must first determine how much of the variability in number of wet basins is accounted for by climatic variables. I used multiple linear regression to examine the relationship between climate variables and percentage of wet basins throughout the Prairie Pothole Region of Canada and the United States. The region was divided into three areas: parkland, Canadian grassland, and United States grassland (i.e., North Dakota and South Dakota). The models - which included variables for spring and fall temperature, yearly precipitation, the previous year's count of wet basins, and for grassland areas, the previous fall precipitation - accounted for 63 to 65% of the variation in the number of wet basins. I then explored the sensitivities of the models to changes in temperature and precipitation, as might be associated with increased greenhouse gas concentrations. Parkland wetlands are shown to be much more vulnerable to increased temperatures than are wetlands in either Canadian or United States grasslands. Sensitivity to increased precipitation did not vary geographically. These results have implications for waterfowl and other wildlife populations that depend on availability of wetlands in the parklands for breeding or during periods of drought in the southern grasslands.The U.S. Government right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Interannual temperature variability in the United States since 1896

The variability of mean monthly temperatures in the United States since 1896 is examined. The results show that the interannual variability reached a peak in the decade centered on 1930 and decreased fairly steadily to a minimum in the decade centered on 1970. This temporal trend is almost completely explained by changes in the variability of winter (December, January, February) mean monthly temperatures. The greatest percent decrease in variability occurred in the Midwest.     

Climate Change Impacts for the Conterminous USA: An Integrated Assessment

Global climate change will impact the hydrologic cycle by increasing the capacity of the atmosphere to hold moisture. Anticipated impacts are generally increased evaporation at low latitudes and increased precipitation at middle and high latitudes. General Circulation Models (GCMs) used to simulate climate disagree on whether the U.S. as a whole and its constituent regions will receive more or less precipitation as global warming occurs. The impacts on specific regions will depend on changes in weather patterns and are certain to be complex. Here we apply the suite of 12 potential climate change scenarios, previously described in Part 1, to the Hydrologic Unit Model of the United States (HUMUS) to simulate water supply in the conterminous United States in reference to a baseline scenario. We examine the sufficiency of this water supply to meet changing demands of irrigated agriculture. The changes in water supply driven by changes in climate will likely be most consequential in the semi-arid western parts of the country where water yield is currently scarce and the resource is intensively managed. Changes of greater than ±50% with respect to present day water yield are projected in parts of the Midwest and Southwest U.S. Interannual variability in the water supply is likely to increase where conditions become drier and to decrease under wetter conditions.     

Interannual and interdecadal variability in United States surface-air temperatures, 1910-87

Monthly mean surface-air temperatures at 870 sites in the contiguous United States were analyzed for interannual and interdecadal variability over the time interval 1910-87. The temperatures were analyzed spatially by empirical-orthogonal-function analysis and temporally by singularspectrum analysis (SSA). The dominant modes of spatio-temporal variability are trends and nonperiodic variations with time scales longer than 15 years, decadal-scale oscillations with periods of roughly 7 and 10 years, and interannual oscillations of 2.2 and 3.3 years. Together, these modes contribute about 18% of the slower-than-annual United States temperature variance. Two leading components roughly capture the mean hemispheric temperature trend and represent a long-term warming, largest in the southwest, accompanied by cooling of the domain's southeastern quadrant. The extremes of the 2.2-year interannual oscillation characterize temperature differences between the Northeastern and Southwestern States, whereas the 3.3-year cycle is present mostly in the Western States. The 7- to 10-year oscillations are much less regular and persistent than the interannual oscillations and characterize temperature differences between the western and interior sectors of the United States. These continental- or regional-scale temperature variations may be related to climatic variations with similar periodicities, either global or centered in other regions; such variations include quasi-biennial oscillations over the tropical Pacific or North Atlantic and quasi-triennial oscillations of North Pacific sea-surface temperatures.The U.S. Government right to retain a non-exclusive, royalty-free licence in and to any copyright is acknowledged.     

Interannual variability and temporal variations of total column ozone in Visakhapatnam from ground based observations

Total column ozone (TCO) measured by the portable, handheld, multichannel Sun photometer (ozonometer-Microtops-II) at Visakhapatnam (17.43°N, 83.14°E; 51 m above mean sea level), India, which is a tropical urban station has been analysed in this study. The results showed the estimate of the annual and seasonal trends of TCO from the period February 2005 to December 2008. The linear regression technique was applied in Microtops II data to study the trend of TCO during 2005?C2008. It also provides statistics of mean and variability on temporal scale. The results showed increasing trend at Visakhapatnam an average of 1.88 DU per year (or 0.61% per year). However the maximum deviation in diurnal variability of TCO were 28 DU (9.19%) while the minimum deviation were ?36 DU (?11.8%) respectively, which is one of the unique result of this study. The range of the seasonal change represents 9.2% of the mean TCO value with maximum/minimum during March/December.     

Possible Impact of Spatial and Temporal Non-Uniformity in Land Surface Temperature Data on Trend Estimation

The present work investigates possible impact of the non-uniformity in observed land surface temperature on trend estimation, based on Climatic Research Unit (CRU) Temperature Version 4 (CRUTEM4) monthly temperature datasets from 1900 to 2012. The CRU land temperature data exhibit remarkable non-uniformity in spatial and temporal features. The data are characterized by an uneven spatial distribution of missing records and station density, and display a significant increase of available sites around 1950. Considering the impact of missing data, the trends seem to be more stable and reliable when estimated based on data with < 40% missing percent, compared to the data with above 40% missing percent. Mean absolute error (MAE) between data with < 40% missing percent and global data is only 0.011°C (0.014°C) for 1900–50 (1951–2012). The associated trend estimated by reliable data is 0.087°C decade^–1 (0.186°C decade^–1) for 1900–50 (1951–2012), almost the same as the trend of the global data. However, due to non-uniform spatial distribution of missing data, the global signal seems mainly coming from the regions with good data coverage, especially for the period 1900–50. This is also confirmed by an extreme test conducted with the records in the United States and Africa. In addition, the influences of spatial and temporal non-uniform features in observation data on trend estimation are significant for the areas with poor data coverage, such as Africa, while insignificant for the countries with good data coverage, such as the United States.     

On the observations of Mount St Helens volcanic emissions: Research note

Abstract

The envelopes of dust clouds from the May 18, 1980 eruption of Mount St Helens in Washington State, U.S.A. were plotted as they traversed the northern United States and southern Canada. Visibility observations at many meteorological stations indicated the presence of volcanic ash and smoke and verified trajectory calculations. In addition, sulphur dioxide released by the volcano was detected as it passed over Toronto, Ontario, while satellite photographs showed dust clouds in the upper atmosphere.     

Changes in agro-meteorological indicators in the contiguous United States: 1951–2000

Summary Mosaic changes in regional and local surface air temperatures and precipitation have occurred along with the increase of the average global surface air temperature in the 20th century, particularly in the recent two decades since 1980. From those changes have emerged these questions: how have the changes altered the local and regional agro-meteorological environment and affected the crop productions? These questions especially their spatially varying aspects have not been well examined. The aim of this study is to examining the effects of regional climate change on agro-meteorological environment, in terms of indicators, such as the thermal time (or Growing Degree Days) and growing season length, and to evaluate the influence of environmental change on crop yield. Major results of this study show a significant trend of increase in the thermal time across the western United States and a trend of decrease in thermal time from the U.S. Great Plains to the east coasts at a rate of 20 Growing Degree Days per 10 years. Results also show a significant trend of decreasing annual number of frost days at a rate of 3 days per decade and a trend of lengthening growing season by 4 days per decade in the western United States. Concurrently, the rainfall patterns in the warm season indicate more persistent weeklong wet spells and fewer dry spells in recent decades. These spatial variations of changes in the agrometeorological environment across the contiguous United States indicate substantial regional effects on crop production from the changing climate in the last 5 decades. Detailed geographical variations of the agrometeorological indicators revealed in this study can be beneficial for updating management decisions and practice routines in local and regional agricultural productions.     

世界主要国家气候谈判立场演变历程及未来减排目标分析

在以时间顺序梳理世界主要国家气候谈判立场演变历程的基础上,研究了主要国家在《京都议定书》中减排目标的执行情况,并对这些国家至2025、2030年的中长期减排目标进行了评估。研究发现,美国、加拿大、澳大利亚对待气候变化问题的积极性均与执政者相关,而从当前3个国家执政党看,均表现出不积极减排的立场,至2030年,美国、加拿大、澳大利亚的温室气体排放量比1990年水平下降均低于20%,远低于欧盟至2030年比1990年减排40%的水平。基础四国在国际减排谈判中由最初的反对者逐渐转变为积极参与者,其中,中国不仅提出了国内2030年左右碳排放达峰的减排目标,而且积极提供资金用于其他发展中国家的减排;南非的长期碳排放将趋于稳定,但在2025年之后有反弹的可能;巴西得益于毁林减少在气候谈判中表现积极,至2030年排放量下降显著;而印度至2030年排放路径保持上升趋势。     

美国关于气候变化对国家安全影响的研究述评

近年来,美国关于气候变化对国家安全影响的研究成果频出。在概述其研究现状及主要成果的基础上,分析了美国在该领域研究的特点及其对我国开展相关研究的启示。美国关于气候变化影响国家安全的研究成果主要体现在围绕气候变化影响美国国家安全的方式、范围、程度以及美国的应对之策等几个方面展开了全面而深入的讨论。其突出特色是：第一,在研究理论和方法方面,与时俱进,转型较快;第二,在研究内容方面,既视野开阔,又有较强的针对性;第三,在研究水平上呈现逐步提高的趋势;第四,在研究体制上,形成官、学、研三位一体的联合研究体制。当前,我国的相关研究还处在起步阶段,在未来的研究中可以借鉴美国的一些有益经验。     

An empirical study of the economic effects of climate change on world agriculture

The economic effects of a doubling of atmospheric carbon dioxide concentration on world agriculture under two alternative crop response scenarios are empirically estimated. These effects include both changes in the prices of agricultural commodities as a result of changes in domestic agricultural yields, and changes in economic welfare following altered world patterns of consumption and production of agricultural commodities. Under both scenarios, with a few exceptions, the effects on national economic welfare are found to be quite modest. However, prices of agricultural commodities are estimated to rise considerably under the more pessimistic scenario. Increased agricultural prices reduce consumer surplus and diminish the benefits from climate change that some countries with predicted positive yield effects would otherwise receive.Authorship is equally shared. Reilly and Tobey are with the Resources and Technology Division, Economic Research Service, United States Department of Agriculture. Kane is with the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. We are grateful for the research assistance of Rhonda Bucklin, and the thoughtful comments of three anonymous reviewers. The views expressed in this paper are the authors' own and do not necessarily represent the views of the U.S. Department of Agriculture or the U.S. Department of Commerce.     

On the relations of the rainfall variability and distribution with the mean rainfall over India

Summary Along with averages, rainfall variability and distribution are important climatological information. In this study, using 114 years (1871–1984) data of 306 stations, it is demonstrated that the variability and spatial distribution of annual, summer monsoon and monthly rainfall are highly dependent upon the respective period mean rainfall variation over India. The magnitude of three selected absolute measures of variability, e.g. standard deviation, absolute mean deviation and mean absolute interannual variability is found to increase linearly with mean rainfall.In order to describe the relation between the rainfall frequency distribution and the mean rainfall, a linear regression between the rainfall amount expected with a specified exceedance/non-exceedance probability and the mean rainfall amount is presented. Highly significant linear curves for a large number of probabilities specified in an average probability diagram clearly demonstrate the dependence of the rainfall frequency distribution on mean rainfall over India.With 8 Figures     

Risk-Based Reanalysis of the Effects of Climate Change on U.S. Cold-water Habitat

Summary A probabilistic risk assessment was conducted for the effects of future climate change on U.S. cold-water habitat. Damage functions for the loss of current cold-water fish habitat in the United States and the Rocky Mountain region were integrated with probability distributions for U.S. June/July/August (JJA) temperature change using Monte Carlo techniques. Damage functions indicated temperature thresholds for incipient losses (≥5%) of cold-water habitat in the United States and the Rocky Mountains of 0.6 and 0.4 ^∘C, respectively. Median impacts associated with different temperature distributions suggested habitat loss in 2025, 2050, and 2100 of approximately 10, 20, and 30%, respectively, for the United States and 20, 35, and 50%, respectively, in the Rocky Mountains. However, 2100 losses in excess of 60% and 90% were possible for the United States and the Rocky Mountains, respectively, albeit at low probabilities. The implementation of constraints on greenhouse gas emissions conforming to the WRE750/550/350 stabilization scenarios had little effect on reducing habitat loss out to 2050, but median effects in 2100 were reduced by up to 20, 30, and 60%, respectively. Increased focus on probabilistic risk assessment may be a profitable mechanism for enhancing understanding and communication of climate change impacts and, subsequently, risk management.     

The response of the ‘green revolution’ to climatic variability

The purpose of this research is to assess the climatic sensitivity of high yielding variety (‘HYV’) ‘green revolution’ wheat. Improved multiple regression models were constructed for yields in India and Sonora, Mexico — the two most intensively planted regions in the world. After isolating the most important climatic predictors (which, not surprisingly, are total rainfall over the irrigation basins), the models were reduced to the pre-HYV period, and then re-run with successively more years of HYV input. This test indicated that increased adoption of the HYV package is associated with a significant increase in yield sensitivity to the most important climatic determinants of yield. To serve as a control, the U.S. Winter Wheat region was also modelled with a similar method. Overall, there is no significant increase in yield sensitivity to climate during the same period that HYV's were adopted in Mexico and India. Assuming that there is no change in overall climatic variability, this study indicates that production will nonetheless become more variable, particularly as HYV culture is expanded. Ironically, countries with rapidly expanding populations, that rely increasingly on HYV's, will experience the most significant fluctuations.     

信阳市人体舒适度指数变化及未来趋势分析

利用信阳气象站1961-2013年的观测资料计算逐日人体舒适度指数(CIHB),运用线性倾向估计、滑动平均和滑动标准差,分析了信阳CIHB的变化趋势,以及舒适日数变化趋势。在此基础上,运用R/S分析法对CIHB及舒适日数变化趋势进行了预测。结果表明:1)信阳的年均CIHB呈显著上升趋势,线性趋势为0.016/a。春、冬季的平均CIHB呈显著上升趋势,且趋势强度相当。秋季平均CIHB虽呈上升趋势,但趋势不显著。夏季平均CIHB呈显著下降趋势。冬季CIHB标准差总体上没有明显的增大或减小趋势,夏季CIHB标准差不断减小,表明信阳出现极端天气气候事件的概率没有增加。2)信阳舒适日数呈显著增加趋势,达0.359天/a,冷、热日数呈减少趋势,趋势强度冷日数的大于热日数的。3)通过R/S分析,年、季平均CIHB具有长期相关的特征,未来的年及春、秋、冬季平均CIHB将继续上升,夏季平均CIHB将继续下降。年舒适日数具有长期相关的特征,未来年舒适日数仍将增加,年冷、热日数继续减少。     

Climate change and agriculture: A perspective on priorities for economic policy

Research on the effects of climate change on U.S. agriculture and world grain markets suggests that adaptation will occur with relatively small effects on total production. Additional research shows that reducing emission of greenhouse gases from U.S. agricultural production is relatively expensive compared to encouraging reforestation as an offset to emissions of carbon dioxide. Nevertheless, continued population growth and the increasing inequality of income across countries are likely to exacerbate the adverse effects of climate change. Concepts of sustainability should be expanded to cover industrial as well as agricultural production, and promote the efficient use of fossil fuels in general. Dealing with climate change effectively will require international cooperation and a willingness to address population growth and the divergence of incomes between rich and poor countries.     

The effect of rate of change, variability, and extreme events on the pace of adaptation to a changing climate

When is it time to adopt different technologies, management strategies, and resource use practices as underlying climate change occurs? We apply risk and decision analysis to test hypotheses about the timing and pace of adaption in response to different profiles of climate change and extremes expressed as yield and income variation for a simulated dryland wheat farm in the United States Great Plains. Climate scenarios include gradual change with typical or increased noise (standard deviation), rapid and large change, and gradual change with extreme events stepped through the simulation. We test decision strategies that might logically be utilized by farmers facing a climate trend that worsens crop enterprise outcomes. Adaptation quickens with the rate of change, especially for decision strategies based on performance thresholds, but is delayed by larger climate variability, especially for decision strategies based on recognizing growing differential between adaptive and non-adaptive performance. Extreme events evoke adaptation sooner than gradual change alone, and in some scenarios extremes evoke premature, inefficient, adaptation.     

Long-term Observations for Monitoring Extremes in the Americas

In this paper we discuss data available from Argentina, Mexico, the United States and Canada that are suitable for the analysis of extreme temperature and precipitation events. We also discuss some of the problems of homogeneity and quality control that can potentially affect the observation of extreme values. It is clear that even in countries like the United States and Canada that have a potentially rich source of climate data there are still problems in obtaining homogeneous data necessary to perform thorough studies of time varying changes in extreme events. These types of problems may be compounded if data are needed from countries that do not have a tradition of maintaining large climate archives or observing networks.We also provide two examples of analyses that can be performed with these types of data: (1) the development of climate extremes indices for Canada, and (2) analyses of freezing events for Florida and the effect on the citrus industry. The Canadian example provides a good basis for countries to take indices developed for one country or region and through minor modifications make the index relevant to their own needs. The analysis of freezing events in Florida is a timely example of how extreme events have both ecological and societal impact.     

Transfer Matrices From the AES‐LRT Model

Abstract

The Canadian Atmospheric Environment Service (A ES) Long‐ Range Transport (LRT) model has been used in the Canada‐United States Memorandum of Intent programme to compute transfer matrices in order to quantify the source‐receptor relationships between emission regions and selected receptor sites. Four‐day backward trajectories were computed from the selected sites for the year 1978 and were started from the 925‐mb level(～600 m). The Lagrangian concentration / deposition model computed sulphur concentrations and depositions for 9 receptor sites using an emissions inventory divided into 15 Canadian and25 United States emission regions.

The 40×9 source‐receptor matrices show that the greatest impact on a receptor site usually results from an emission region close to the site although the regions giving the greatest impact for air concentration and wet deposition are not necessarily identical. In addition, the matrices show the impacts of all the emission regions on all of the receptor sites ranked by the magnitudes of the matrix elements. The per cent contribution from each emission region at each receptor site is shown as well as the overall per cent contributions from both Canada and the United States.

These matrices are an attempt to quantify source‐receptor relationships in Canada and the United States for assessing emission control strategies. The uncertainties associated with the matrices are being studied.