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普查了1986-2000年冬季河南省70个暴雪的个例资料,分析了河南省暴雪的时空分布特征及其天气形势特征,建立了横槽型和两槽一脊型的暴雪天气学模型.通过对2003年2月9-10日(横槽型)和2003年3月4-5日(两槽一脊型)河南省出现的两场区域性暴雪过程的环流背景、成因特征、物理量等的对比分析发现,暴雪天气一般发生在经向环流与纬向环流相互调整之时,低空急流与低层切变线上气旋性曲率东扩或低涡东移是产生暴雪的重要原因,冷垫是产生暴雪的基本条件,最后给出了两类典型暴雪的具体预报特征. 相似文献
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分析了2001年1月6日河南省中北部出现的区域性暴雪天气过程中天气系统的演变、物理量场，并对数值预报产品作出天气学解释。 相似文献
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2003年河南省两类典型暴雪天气对比分析 总被引：1，自引：0，他引：1
通过对2003年2月9～10日和3月4～5日河南省出现的两场区域性暴雪的环流背景、成因特征、物理量的对比分析,得出了低层切变线上气旋性曲率东扩或低涡东移是产生暴雪重要原因的结论;并给出了这两种不同类型暴雪天气的预报着眼点. 相似文献
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2003年河南省两类典型暴雪天气对比分析 总被引：6，自引：0，他引：6
通过对2003年2月9～10日和3月4～5日河南省出现的两场区域性暴雪的环流背景、成因特征、物理量的对比分析，得出了低层切变线上气旋性曲率东扩或低涡东移是产生暴雪重要原因的结论；并给出了这两种不同类型暴雪天气的预报着眼点。 相似文献
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2000年冬季阿勒泰区域性大-暴雪成因分析 总被引：2，自引：1，他引：2
对形成2000年冬季阿勒泰地区出现的6场区域性大－暴雪天气过程的欧亚大尺度环流与天气尺度影响系统的特征、水汽条件及垂直运动条件等进行综合分析，得出形成阿勒泰区域性大－暴雪天气的重要指标，从而进一步提高阿勒泰区域性大－暴雪天气的预报准确率，对防灾减灾具有重要意义。 相似文献
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暴雪是我市冬季和初春的重要灾害性天气之一。本文分析了我市近500年暴雪的发生规律,并着重对1977～1989年出现的17次区域性暴雪的气候特征、天气形势和单点资料进行研究,从而建立了本市区域性暴雪的预报方法。经两年试用,具有较好的效果。一、天气标准和资料来源日纯雪量≥5毫米或雪深增量≥5厘米为大雪日,日纯雪量≥10毫米或雪深增量≥10厘米为暴雪日;全市有≥3站大雪,其中≥1站暴雪,称区域性暴雪日。 相似文献
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本文对吉林省延边地区的暴雪灾害及其天气气候特征、环流形势特征及主要影响系统等进行了分析和探讨。结果表明：延边暴雪灾害具有明显的区域性特征，其环流形势特征和主要影响系统也与产生全省暴雪的环流形势和影响系统有很大差别，在天气分析预报中应引起注意。 相似文献
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雪灾是内蒙古地区的主要的气象灾害，对全区牧业和人民生活造成了严重危害和影响。在充分分析内蒙古地区气候特征的基础上，依据SVM回归方法，利用T213资料，建立了暴雪的SVM回归方法预报模型，建立了自动化的SVM暴雪预报业务系统，并对其进行了业务试验。给出了依据SVM方法建立的暴雪实时业务预报系统的检验结果。结果表明，SVM回归方法能运用于暴雪的预报，建立的自动化的SVM暴雪预报业务系统能在预报业务中发挥了一定的作用。 相似文献
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Biogenic Volatile Organic Compounds (VOC): An Overview on Emission, Physiology and Ecology 总被引：50，自引：0，他引：50
This overview compiles the actual knowledge of the biogenic emissions of some volatile organic compounds (VOCs), i.e., isoprene, terpenes, alkanes, alkenes, alcohols, esters, carbonyls, and acids. We discuss VOC biosynthesis, emission inventories, relations between emission and plant physiology as well as temperature and radiation, and ecophysiological functions. For isoprene and monoterpenes, an extended summary of standard emission factors, with data related to the plant genus and species, is included. The data compilation shows that we have quite a substantial knowledge of the emission of isoprene and monoterpenes, including emission rates, emission regulation, and biosynthesis. The situation is worse in the case of numerous other compounds (other VOCs or OVOCs) being emitted by the biosphere. This is reflected in the insufficient knowledge of emission rates and biological functions. Except for the terpenoids, only a limited number of studies of OVOCs are available; data are summarized for alkanes, alkenes, carbonyls, alcohols, acids, and esters. In addition to closing these gaps of knowledge, one of the major objectives for future VOC research is improving our knowledge of the fate of organic carbon in the atmosphere, ending up in oxidation products and/or as aerosol particles. 相似文献
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The spatial and temporal variations of daily maximum temperature(Tmax), daily minimum temperature(Tmin), daily maximum precipitation(Pmax) and daily maximum wind speed(WSmax) were examined in China using Mann-Kendall test and linear regression method. The results indicated that for China as a whole, Tmax, Tmin and Pmax had significant increasing trends at rates of 0.15℃ per decade, 0.45℃ per decade and 0.58 mm per decade,respectively, while WSmax had decreased significantly at 1.18 m·s~(-1) per decade during 1959—2014. In all regions of China, Tmin increased and WSmax decreased significantly. Spatially, Tmax increased significantly at most of the stations in South China(SC), northwestern North China(NC), northeastern Northeast China(NEC), eastern Northwest China(NWC) and eastern Southwest China(SWC), and the increasing trends were significant in NC, SC, NWC and SWC on the regional average. Tmin increased significantly at most of the stations in China, with notable increase in NEC, northern and southeastern NC and northwestern and eastern NWC. Pmax showed no significant trend at most of the stations in China, and on the regional average it decreased significantly in NC but increased in SC, NWC and the mid-lower Yangtze River valley(YR). WSmax decreased significantly at the vast majority of stations in China, with remarkable decrease in northern NC, northern and central YR, central and southern SC and in parts of central NEC and western NWC. With global climate change and rapidly economic development, China has become more vulnerable to climatic extremes and meteorological disasters, so more strategies of mitigation and/or adaptation of climatic extremes,such as environmentally-friendly and low-cost energy production systems and the enhancement of engineering defense measures are necessary for government and social publics. 相似文献
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Understanding potential future influence of environmental, economic, and social drivers on land-use and sustainability is critical for guiding strategic decisions that can help nations adapt to change, anticipate opportunities, and cope with surprises. Using the Land-Use Trade-Offs (LUTO) model, we undertook a comprehensive, detailed, integrated, and quantitative scenario analysis of land-use and sustainability for Australia’s agricultural land from 2013–2050, under interacting global change and domestic policies, and considering key uncertainties. We assessed land use competition between multiple land-uses and assessed the sustainability of economic returns and ecosystem services at high spatial (1.1 km grid cells) and temporal (annual) resolution. We found substantial potential for land-use transition from agriculture to carbon plantings, environmental plantings, and biofuels cropping under certain scenarios, with impacts on the sustainability of economic returns and ecosystem services including food/fibre production, emissions abatement, water resource use, biodiversity services, and energy production. However, the type, magnitude, timing, and location of land-use responses and their impacts were highly dependent on scenario parameter assumptions including global outlook and emissions abatement effort, domestic land-use policy settings, land-use change adoption behaviour, productivity growth, and capacity constraints. With strong global abatement incentives complemented by biodiversity-focussed domestic land-use policy, land-use responses can substantially increase and diversify economic returns to land and produce a much wider range of ecosystem services such as emissions abatement, biodiversity, and energy, without major impacts on agricultural production. However, better governance is needed for managing potentially significant water resource impacts. The results have wide-ranging implications for land-use and sustainability policy and governance at global and domestic scales and can inform strategic thinking and decision-making about land-use and sustainability in Australia. A comprehensive and freely available 26 GB data pack (http://doi.org/10.4225/08/5604A2E8A00CC) provides a unique resource for further research. As similarly nuanced transformational change is also possible elsewhere, our template for comprehensive, integrated, quantitative, and high resolution scenario analysis can support other nations in strategic thinking and decision-making to prepare for an uncertain future. 相似文献
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针对当前东北地区过量施氮的问题,研究减量施氮对春玉米生长发育、产量及籽粒品质的影响,对优化氮肥的科学管理技术,促进春玉米生产绿色高效发展具有重要意义。本研究以丹玉405为试验材料,通过大田播种的方式,以农民习惯性施氮量为对照,设置11.1%、55.5%和100%三个水平减量施氮试验,分析春玉米生长发育、产量和籽粒品质对减量施氮的响应机制。结果表明：玉米苗期,减氮导致生长发育指标（株高、茎粗、叶面积指数、生物量干、鲜重、叶片比重等）均减少,不利于地上部的生长和干物质向叶片分配,随着减氮量的增加,减少幅度增加。苗期以后,适量减氮促进玉米地上部的生长,株高、茎粗、叶面积指数、生物量和叶片占比等生物学性状有增加趋势。适量减氮导致果穗长、果穗粗、百粒重、理论产量、籽粒含水量和淀粉含量增加,籽粒脂肪含量减少,氨基酸和粗蛋白含量呈先增加后减少。随着减氮量的增加,果穗长、果穗粗、百粒重和理论产量增加幅度均减小,籽粒含水量和淀粉含量增加幅度增大,脂肪含量减少幅度减小。减氮11.1%时,果穗长、果穗粗和理论产量增加幅度最大,分别为1.9%、3.7%和11.5%。当施氮量为240 kg·hm-2（减氮11.1%）时,玉米产量达到最大,为945.4 g·m-2,籽粒脂肪含量最少,为2.4 g·100 g-1;氨基酸含量最大,为83.9 μmol·g-1;粗蛋白含量最高,为6.8%。研究结果可为当地的玉米生产提供更加完善的施肥管理,指导农户科学施肥。 相似文献
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Although the Namib Desert is classified as hyperarid, with rainfall extremely rare, there are several other sources of atmospheric moisture, namely, humidity, dew and fog, which make it possible for organisms to live there. Methods to use these sources include locating moist micro-climates, drinking from wet surfaces, consuming moist food, collecting water on the body, and absorbing water vapour. In describing these mechanisms from published sources, we highlight the work of Professor Gideon Louw, to whom we dedicate this paper. Louw's pioneering work on water relations and economy, which includes osmoregulation in desert plants and animals such as grass, beetles, and springbok, established a foundation that inspired numerous studies by colleagues and students. Ecophysiology provides many more lessons that have potential to be mimicked and applied in the occult collection of water in arid regions. 相似文献
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利用江苏省气象局与美国强风暴实验室联合开发的高精度数值分析及预报系统(Precision Weather Analysis and Forecast System,PWAFS)对雷达资料同化中径向速度资料的两种坐标转换方案进行对比分析。Grid方案将雷达径向速度资料通过最小二乘法从极坐标映射到模式三维网格;Tilt方案将雷达径向速度资料通过双线性插值在水平方向插值至标量水平网格,但在垂直方向不进行插值,保留在雷达仰角对应的高度上。两种方案对反射率资料的处理均是插值到模式三维网格点。Grid方案在近雷达处进行平滑,在远雷达处进行插值,会导致低层数据平滑,Tilt方案减少了雷达径向风观测垂直插值引发的误差,更多的保留了雷达观测的特性。本研究分别通过龙卷、大风及梅雨锋暴雨个例对这两种方案的同化结果进行对比分析。龙卷个例中Grid方案得到了部分虚假的较大的同化风场,Tilt方案结果清楚展示了龙卷发生位置的回波及流场的精细结构。大风个例中两种方案得到的最大风速值差3 m·s^-1,Tilt方案的结果更接近观测最大风速值,且得到的大风速区分布更符合观测。梅雨锋暴雨个例中Grid方案对东北及西南两个区域的大风速区均未能很好的反映,Tilt方案得到的水平风速大值区范围明显优于Grid方案。在靠近雷达中心的低层,观测资料密集,Tilt方案能够更好的反应实际大气状态。但是因为缺乏其他观测资料进行验证,两种方案的效果还需要利用数值预报或其他方法进行对比。 相似文献
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K. Slezakova M. C. Pereira M. A. Reis M. C. Alvim-Ferraz 《Journal of Atmospheric Chemistry》2007,58(1):55-68
Epidemiological studies initially considered the impact of total solid particles on human health, but according to the acquired
knowledge about the worse effect of smaller particles, those studies turned to consider the impact of PM10. However, for the last decade PM2.5 began to be more important, once as they are smaller they can penetrate deeper in the lungs, being possible their trapping
in alveoli and worse effects on human health. Therefore, more information on PM2.5 should be provided namely concerning the levels and elemental composition. Considering the relevance of traffic on the emission
of particles of small sizes, this work included the detailed characterization of PM10 and PM2.5, sampled at two sites directly influenced by traffic, as well as at two reference sites, aiming a further evaluation of the
influence of PM10 and PM2.5 on public health. The specific objectives were to study the influence of traffic emission on PM10 and PM2.5 characteristics, considering concentration, size distribution and elemental composition. PM10 and PM2.5 samples were collected using low-volume samplers; the element analyses were performed by particle induced X-ray emission
(PIXE). At the sites influenced by traffic emissions PM10 and PM2.5 concentrations were 7–9 and 6–7 times higher than at the background sites. The presence of 17 elements (Mg, Al, Si, P, S,
Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb) was determined in both PM fractions; particle metal contents were 3–44 and
3–27 times higher for PM10 and PM2.5, respectively, than at the backgrounds sites. The elements originated mostly from anthropogenic activities (S, K, V, Mn,
Ni, Zn and Pb) were predominantly present in PM2.5, while the elements mostly originated from crust (Mg, Al, Si and Ca) predominantly occurred in PM2.5–10. The results also showed that in coastal areas sea salt spray is an important source of particles, influencing PM concentration
and distributions (PM10 increased by 46%, PM2.5/PM10 decreased by 26%), as well as PM compositions (Cl in PM10 was 11 times higher). 相似文献
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James D. Ford Lea Berrang-Ford Malcolm King Chris Furgal 《Global Environmental Change》2010,20(4):668-680
Climate change has been identified as potentially the biggest health threat of the 21st century. Canada in general has a well developed public health system and low burden of health which will moderate vulnerability. However, there is significant heterogeneity in health outcomes, and health inequality is particularly pronounced among Aboriginal Canadians. Intervention is needed to prevent, prepare for, and manage climate change effects on Aboriginal health but is constrained by a limited understanding of vulnerability and its determinants. Despite limited research on climate change and Aboriginal health, however, there is a well established literature on Aboriginal health outcomes, determinants, and trends in Canada; characteristics that will determine vulnerability to climate change. In this paper we systematically review this literature, using a vulnerability framework to identify the broad level factors constraining adaptive capacity and increasing sensitivity to climate change. Determinants identified include: poverty, technological capacity constraints, socio-political values and inequality, institutional capacity challenges, and information deficit. The magnitude and nature of these determinants will be distributed unevenly within and between Aboriginal populations necessitating place-based and regional level studies to examine how these broad factors will affect vulnerability at lower levels. The study also supports the need for collaboration across all sectors and levels of government, open and meaningful dialogue between policy makers, scientists, health professionals, and Aboriginal communities, and capacity building at a local level, to plan for climate change. Ultimately, however, efforts to reduce the vulnerability of Aboriginal Canadians to climate change and intervene to prevent, reduce, and manage climate-sensitive health outcomes, will fail unless the broader determinants of socio-economic and health inequality are addressed. 相似文献
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For many Indigenous Peoples in the Circumpolar North, cultural engagement and continuity across generations is directly related to relationships between and among people, animals, and landscapes. However, minimal research outlines the emotional responses and disruptions to culture and identity that are driven by ecological change, and the subsequent cultural dimensions of coping and adapting to this uncertainty. Through a case study that explores how caribou population declines and a caribou hunting ban are impacting Inuit in the Nunatsiavut and NunatuKavut regions of Labrador, Canada, this article examines the critical interplay between cultural continuity and adaptive capacity for responding to ecological uncertainty. More specifically, this study: 1) described the central role that caribou play for Inuit emotional wellness, identity, and cultural continuity; 2) explored how the rapid declines of caribou in Labrador are affecting Inuit emotional wellness, identity, and cultural continuity; and 3) characterized the ways in which Inuit are adapting to these emotio-social, cultural, and ecological changes. Drawing from an Inuit-led, multi-year, multi-media qualitative and visual media research program, data from video interviews (n = 84: Nunatsiavut region: n = 54; NunatuKavut region: n = 30) were analyzed using a video-based qualitative analysis, constant-comparative methods, and inductive qualitative approach. Results indicated that caribou are a foundational element for Inuit emotional wellness, identity, and cultural continuity. The changes in caribou populations are resulting in complex emotional responses, losses to cultural meaning and knowledge, and alterations to Inuit identities. The impacts on emotions, identity, and cultural continuity related to Inuit-caribou relations at an individual and collective level reflect the interconnections between cultural continuity and adaptive capacity that underlie the loss of this culturally important species. Though this research focuses on two Inuit groups and caribou in Labrador, the insights from these lived experiences highlight the ongoing cultural and identity consequences associated with species declines occurring globally. 相似文献