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1.
为探究不同生育期不同程度复合高温干旱胁迫对夏玉米生长发育及产量形成的影响,以夏玉米品种“登海685”为试验材料,于2022年6—9月在衡水农业气象试验站开展夏玉米高温干旱田间胁迫试验。在拔节—抽雄和抽雄—乳熟两个生育期分别进行试验。干旱处理设置为轻旱和重旱两个水平。通过增温箱分别在两个生育期进行高温处理,这样每个生育期有轻旱、轻旱高温、重旱、重旱高温四种胁迫处理,各处理有两个重复。此外设置全生育期增温无旱处理和对照组,共10个处理,对株高、叶面积、干物质重及产量构成要素进行观测。结果显示,夏玉米全生育期增温会增加株高和叶面积,但会降低干物质积累导致产量下降;夏玉米在拔节—抽雄和抽雄—乳熟期发生严重的干旱可显著降低株高,但干旱复合高温后影响程度变弱;两个时期发生高温复合干旱与单一干旱相比对玉米叶面积的降低程度更明显;两个时期发生高温干旱胁迫对玉米植株干物质的降低主要由果实干物质降低带来;这两个阶段高温干旱胁迫均会影响产量形成,但拔节—抽雄期干旱对产量形成的影响更大,而抽雄—乳熟期高温的影响更大。  相似文献   

2.
基于ERA5和ERA5-LAND再分析资料,利用水量平衡分解法,将净降水量(降水量减蒸发量,P-E)的变化分解为热动力贡献、热力学贡献和涡动贡献,分析了2022年发生在长江中下游平原的极端干旱事件的机理和演变过程,并将其与2013年同样发生在长江中下游的高温干旱事件进行对比分析。净降水量分析表明,2022年长江中下游平原汛期前期(5—6月)干旱主要由降水量减小导致,水量平衡分解分析显示,湍流涡动与平均环流变化的贡献是早期干旱的主要因子;中期(7—8月)的高温增强了地表蒸散发,尤其是裸土蒸发的增强,加剧了干旱程度,水量平衡分解显示,表征温度升高引起的水汽含量变化的热力贡献对干旱加剧的贡献最大;后期(9—10月)高温进一步引发平均环流变化导致的热动力贡献延长了干旱持续时间。而2013年的高温干旱为高温引发的热力学贡献主导,持续事件短,干旱程度弱。本文对2022年发生在长江中下游平原的高温干旱复合型极端事件的发展和演变过程的剖析,可为湿润区极端高温干旱事件的预测预警提供参考。  相似文献   

3.
从气象干旱的角度出发,对比分析了基于广义极值分布理论构建的新干旱指数GEVI(Generalized Extreme Value Index)和我国广泛应用的SPI (Standardized Precipitation Index)指数,详细讨论了SPI和GEVI指数在西北地区干旱监测中的适用性.结果表明,SPI和GEVI指数在计算原理上具有相似性,在一定程度上衡量某一地区干旱程度和反映干旱范围方面具有一致性和可替代性.但因两者采取不同的分布形态,对干旱等级的衡量效果不尽相同.GEVI指数在拟合降水量分布函数时更为详尽、客观.在西北5省(区)的干旱监测中,对地处干旱半干旱区的甘肃来说,GEVI指数在于旱强度判定方面优于SPI指数;对年降水量最少的新疆地区来说,GEVI指数比SPI指数在干旱监测方面更为适用.  相似文献   

4.
利用统计方法,分析了九江市1951~2003年夏季高温干旱的气候特征,发现九江市夏季高温干旱的变化具有明显的阶段性,夏季高温经历了低、高、低、高4个阶段,目前九江市处于高温干旱的高变率阶段;九江市夏季高温干旱变化具有多时间尺度的特点,存在13a的显著周期和9a、4a的次显著周期。  相似文献   

5.
中国高温热浪危害特征的研究综述   总被引:15,自引:2,他引:15  
徐金芳  邓振镛  陈敏 《干旱气象》2009,27(2):163-167
全面综述了高温热浪气象灾害在危害特点、标准与类型、气候特征、形成原因、对全球气候变暖的响应、监测和预测与预警技术、减灾技术及应对策略等8个方面的研究成果.高温热浪是一种较短时间尺度的天气灾害,基本天气特征是高温低湿,除高寒地带外,每年6~8月在全国各地均有发生.大气环流异常是高温热浪形成的直接原因,气候变暖变干是导致高温热浪频繁发生的重要原因.深刻了解高温热浪的危害特征,对应对高温热浪发生发展、监测预测、安全生产、趋利弊害具有重要的指导作用.  相似文献   

6.
江西盛夏高温干旱的气候分析及预测研究   总被引:1,自引:4,他引:1  
采用逐日降水及最高气温资料,计算了盛夏高温干旱指数;应用500hPa月平均高度及西太平洋副高(简称副高)特征量、海温资料,分析了盛夏高温干旱与副高、海温的关系。结果表明:副高偏强偏西是盛夏高温干旱的典型特征;冬季厄尔尼诺偏强、上年秋冬季赣中降水量异常偏多及4月赣南气温明显偏高是有利于全省盛夏高温干旱发生的强信号。  相似文献   

7.
拉尼娜事件与我国气候密切相关,近年来重庆地区频繁出现的高温干旱与拉尼娜事件的关联值得深入研究。研究重庆高温干旱的特征及其对拉尼娜事件的响应,以期对该地区的高温干旱预测和预警提供科学依据。基于1981—2022年气象干旱综合指数MCI(Meteorological Drought Composite Index)、高温日数、NCEP/NCAR(National Centers for Environmental Prediction/National Center for Atmospheric Research)再分析环流场和Hadley海温数据,分析重庆夏季高温和气象干旱的时空分布特征,探寻拉尼娜事件对高温干旱的影响及其环流异常特征。结果表明:夏季是重庆干旱发生频率最高且持续时间最长的季节,高温干旱主要集中在东北部及长江沿线地区。高温与干旱之间存在相互促进的关系,持续高温促进重度干旱的形成,而长期干旱也可能导致极端高温的发生。赤道中东太平洋海温在冬、春季处于拉尼娜状态,对重庆夏季的高温和干旱有显著影响。弱拉尼娜事件倾向于引发高温,而中等强度拉尼娜事件更易导致干旱。中部型和东部型拉尼娜...  相似文献   

8.
2013年夏季湖南严重高温干旱及其大气环流异常   总被引:2,自引:0,他引:2  
利用湖南省97个台站降水、气温资料和NECP/NCAR再分析资料以及NOAA卫星观测的OLR场资料,系统分析了2013年6月30日至8月14日湖南持续高温干旱的时空分布及同期大气环流异常特征。结果表明:2013年夏季是湖南1951年以来降水最少、高温干旱程度最严重的一年。西太平洋副热带高压强度偏强、西伸脊点偏西,湖南处在副高控制下,盛行下沉气流是发生持续高温干旱的直接原因;西太平洋副高内增强的下沉气流,致使多数县市高温日数和极端高温突破历史同期最高记录。位于菲律宾附近的OLR低值带中心偏西,致使副热带地区下沉区偏西,进而造成西太平洋副高偏强偏西。此外,湖南地区上空为水汽输送异常辐散中心,这在一定程度上促使了干旱的发生发展。  相似文献   

9.
高温热浪和干旱是影响陆地生态系统最主要的极端天气气候事件。已有关于中国高温热浪和干旱历史变化的定量研究主要针对全国范围、地理分区或单一区域,对于我国生态脆弱区相关极端事件的历史变化特征尚不清楚。本文利用中国CN05.1格点化观测数据集中的日最高气温观测资料和全球逐月标准化降水蒸发指数格点数据,分析了中国典型生态脆弱区1980~2014年发生的高温热浪和干旱的时空变化特征。结果表明:1980~2014年中国生态脆弱区的年高温日数和热浪次数整体呈增加趋势,两者变化趋势的空间分布类似。在空间分布上,高温热浪显著增加的区域主要位于北方生态脆弱区的中部和西部以及南方生态脆弱区的东部。其中,高温热浪增长显著的面积比率在西南岩溶山地石漠化脆弱区最高,在南方农牧脆弱区最低。区域平均来看,除南方农牧脆弱区较少发生高温热浪外,各脆弱区高温日数和热浪次数均呈现增加趋势,且除北方农牧林草区外,其余脆弱区增加趋势显著。北方生态脆弱区高温和热浪的发生频率和年际变化在20世纪90年代中期起均迅速增加。此外,中国生态脆弱区东部多呈现变干趋势且中等和极端干旱发生月数增多,其余地区则多变湿且极端干旱发生月数减少;区域平均来看,除西南岩溶山地石漠化脆弱区区域平均的干旱发生月数呈现显著增加趋势以外,其他区域的干湿和干旱发生月数的变化趋势小且不显著。  相似文献   

10.
近39a册亨县高温干旱气候特征分析   总被引:2,自引:2,他引:0  
利用统计方法,分析册亨县1970-2008年的气候特征,发现册亨县高温干旱的变化具有明显的阶段性,高温经历了由高到低再到高3个阶段,干旱程度则是春季重于夏季。  相似文献   

11.
The objective of this paper is to develop independent and systematic criteria for assessing CCS policy in terms of its level of policy integration. We believe that we should assess CCS policy in terms of the distance to an ideal integrated CCS policy in order to keep track of its trajectory toward sustainable development. After reviewing the existing literature of environmental policy integration, an assessment framework for integrated CCS policy is developed based on Arild Underdal's notion of ‘integrated policy’ then, its usefulness is demonstrated by applying it to CCS policies in Japan and Norway. In the final part, we summarize the findings of the cases and conclude with some observations regarding explanatory factors of the difference in terms of the achieved level of policy integration between Japan and Norway's CCS policies, and some policy implications derived from the analysis based on the framework.  相似文献   

12.
Simultaneous measurements of the activity concentrations of radon and its progeny, and conductivity of both polarities i.e., positive and negative conductivities, were made at a height of 1 m above the ground at Mysore (12°N, 76°E, 767 m above mean sea level), India. Diurnal and seasonal variations of activities of radon and its progeny show their peak values in the early morning hours throughout the year. Observations show an increase in the concentration of radon and its progeny during nighttime compared to the daytime values, and are higher in winter than in other seasons. The electrical conductivity of the atmosphere that depends on the ionization rate also exhibits similar trends. These results are discussed in terms of ionization rate due to radioactivity and the influence of meteorological parameters on radioactivity. The results also show that the concentrations of radon, its progeny, and the electrical conductivity of both polarities exhibit a positive correlation with the relative humidity and are negatively correlated with the temperature of the atmosphere.  相似文献   

13.
The Tornado and Storm Research Organisation (TORRO) was formed in the UK in 1974 in order to determine realistic spatial, temporal and intensity distributions of tornadoes in the UK and, eventually, throughout Europe. Currently, TORRO's databases contain nearly 2000 tornadoes and over 550 waterspouts for the UK alone. In 1972, TORRO's founder, Terence Meaden, devised the Tornado Intensity Scale. This scale enables the wind speeds of tornadoes to be rated on a scale from T0 to T10, or more (since it is an open-ended scale). Using this scale, estimates have been made of the statistical return periods of differing intensities of UK tornadoes. TORRO's research into understanding the conditions of tornado development is ultimately intended to lead to issuing forecasts of tornadoes. In 1991, TORRO issued the first tornado watch in the UK for 12 November and this proved to be accurate—not only did three property-damaging tornadoes strike East Anglia but the forecast maximum intensity of T5 was attained. In 1975, TORRO expanded its activities to include conventional thunderstorm reporting and investigations. In 1982, TORRO incorporated the British and Irish thunderstorm data-collection organisation, the Thunderstorm Census Organisation (TCO), which was established in 1924. By the early 1980s, TORRO's network of voluntary thunderstorm observers, located throughout the UK and Ireland and increasingly in other European countries, numbered around 350 and the network continues to grow. In addition to TORRO's early focus on tornadoes and thunderstorms, its data collection and research has expanded to consider other whirlwinds (such as waterspouts and land devils), hailstorms, lightning (including ball lightning) and blizzards/heavy snowfalls. In 1996, TORRO began providing easy access to its databases (e.g. post-1995 UK and European severe weather events, especially tornadoes and hailstorms) and other information via its internet site at http://www.torro.org.uk/. Building on over 25 years of experience—and of the half a century of the TCO before it—TORRO continues to expand its European role in severe weather data collection and research, helped by the on-going appointment of European representatives and its increasing European membership.  相似文献   

14.
针对荷兰Avantes公司因未开放光谱仪的串行通信口,不能适合工业上较长距离与PC机进行通信的弊端,提出了PC机与Avantes光谱仪串口通信的方案,包括通信部分硬件结构,通信协议的制定及Windows下VC++串口程序的实现,在此基础上,开发了光谱仪数据采集与波形实时显示系统.应用结果表明,该系统能稳定地运行,具有很强的实用性.  相似文献   

15.
随着气象卫星技术的发展,卫星观测能力不断提升,全球气象卫星观测体系逐步形成。美国、欧洲和中国都建立了极轨和静止气象卫星观测系统,日本、韩国等国家也拥有各自的气象卫星。与卫星发展初期相比,现在的气象卫星在空间分辨率、时间分辨率、光谱分辨率以及波段覆盖范围等方面都有了极大的提高。与之相伴,气象卫星遥感资料应用也取得了长足的进步。卫星应用领域不断拓展,新的资料处理方法不断涌现,数据使用也完成了从定性向定量的跨越。本文将在总结目前气象卫星遥感载荷观测能力的基础上,着重介绍卫星资料在天气分析、环境灾害监测以及气候变化研究方面的应用。  相似文献   

16.
The development of vertical vorticity under adiabatic condition is investigated by virtue of the view of potential vorticity and potential temperature (PV-θ) and from a Lagrangian perspective. A new concept of generalized slantwise vorticity development (GSVD) is introduced for adiabatic condition. The GSVD is a coordinate independent framework of vorticity development (VD), which includes slantwise vorticity development (SVD) when a particle is sliding down the concave slope or up the convex slope of a sharply tilting isentropic surface under stable or unstable condition. The SVD is a special VD for studying the severe weather systems with rapid development of vertical vorticity. In addition, the GSVD clarifies VD and SVD. The criteria for VD and SVD demonstrate that the demand for SVD is much more restricted than the demand for VD. When an air parcel is moving down the concave slope or up the convex slope of a sharply tilting isentropic surface in a stable stratified atmosphere with its stability decreasing, or in an unstable atmosphere with its stability increasing, i.e., its stability θ z approaches zero, its vertical vorticity can develop rapidly if its C D is decreasing. The theoretical results are employed to analyze a Tibetan Plateau (TP) vortex (TPV), which appeared over the TP, then slid down and moved eastward in late July 2008, resulting in heavy rainfall in Sichuan Province and along the middle and lower reaches of the Yangtze River. The change of PV 2 contributed to the intensification of the TPV from 0000 to 0600 UTC 22 July 2008 when it slid upward on the upslope of the northeastern edge of the Sichuan basin, since the changes in both horizontal vorticity η s and baroclinity θ s have positive effects on the development of vertical vorticity. At 0600 UTC 22 July 2008, the criterion for SVD at 300 K isentropic surface is satisfied, meaning that SVD occurred and contributed significantly to the development of vertical vorticity. The appearance of the stronger signals concerning the VD and SVD surrounding the vortex indicates that the GSVD concept can serve as a useful tool for diagnosing the development of weather systems.  相似文献   

17.
环青海湖地区气候变化及其对荒漠化的影响   总被引:30,自引:5,他引:30  
对环青海湖地区1976年以来的气温、降水、蒸发等气候要素的气候变化趋势及突变现象进行了分析和检验。结果表明:年平均气温及春、夏、秋、冬四季气温均呈上升趋势,其中以秋、冬两季最为明显;年平均降水量及春、夏、冬季降水自90年代后出现减少趋势,秋季降水始终呈减少趋势,且线性变率达-7.28mm/10a;各季及年蒸发量呈增大趋势,其中年、夏季蒸发量的线性变率分别为11.7、9.39mm/a。各季及年气温出现过一次明显的增暖现象;降水虽然出现过一次明显的增加和减少,但增加出现在80年代,而减少则出现在90年代;同样,蒸发也出现过一次明显的增大和减小现象,只是减少出现在80年代,而增大而出现在90年代。这种气候趋势和突变现象的发生,加剧了环青海湖地区荒漠化的蔓延,致使草地退化、河流流量减少、湖泊水位下降,生态环境受到严重影响。  相似文献   

18.
Germany's current efforts to decarbonize its electricity system are analysed. As nuclear power and fossil power plants equipped with carbon capture and storage were ruled out in 2011, renewable electricity generation (RES) together with electricity savings are the primary focus for achieving decarbonization. Germany aims to have RES account for at least 80% of its electricity by 2050. Achieving renewable generation needs strong political support and regulatory provisions for its market integration. Four main technical and regulatory challenges are the maintenance of a steady and efficient expansion of RES, the provision of balancing capacities, the realization of the targeted electricity savings, and the smart adaptation of the transport and distribution grid. An overview of the existing and planned regulatory provisions for decarbonization are described, and some gaps identified, particularly with regard to the overall management of the process, the inclusion of electricity savings and the interference of Germany's decarbonization strategies with neighbouring countries. Policies that both accelerate grid expansion and direct RES expansion should immediately be put in place and can be supported by a targeted mobilization of balancing capacities. Electricity savings are a significant and cost-efficient strategy for low-carbon electricity.

Policy relevance

Germany is actively converting its national electricity system towards a fully renewable one. As renewable electricity has reached about a quarter of total consumption, a number of technical and regulatory challenges arise. Current discussions and plans are described for the four main challenges: maintaining and optimizing high investment rates into RES generation technologies, providing balancing capacities, reducing demand, and adapting the grid to the changing needs. Policy recommendations for these four tasks highlight the need to intensify electricity demand reduction and also consider the potential interactions between the German electricity system and its neighbouring countries.  相似文献   

19.
陈英  谢万锈  徐彬 《干旱气象》2013,(3):627-632
从自动站与人工站观测方式的区别人手,对民勤国家基准气候站观测的数据进行整理与对比分析得出:(1)2种观测方式数据序列中,本站气压2a平均差值为0.1hPa,差值变幅在~0.3~0.5hPa;气温2a平均差值-0.1℃,差值变幅在-0.1~0.0℃之间;相对湿度2a平均差值为-1%,差值变幅在一4%~2%之间;2min平均风速2a平均差值为0.5m/s,差值变幅在0.3~0.7m/s之间,10min平均风速2a平均差值为0.4m/s,差值变幅在0.4~0.5m/s之间;地面温度2a平均差值为0.6℃,差值变幅在0.0~1.2℃之间。本站气压、气温、相对湿度、风向风速、地温差值虽然不固定,但对历史资料的序列连续性影响不显著;(2)各要素中差值最大的是地面最高温度,2a平均差值为1.8oC,差值变幅在-1.7~4.3℃之间;(3)自动站的观测结果比人工观测更真实、准确、科学,更接近大气中的实际情况。  相似文献   

20.
The atmospheric concentration of 210Pb was determined for two years at six stations in the western North Pacific region. The following results were obtained and discussed by comparing them with those of Al. The atmospheric concentration of 210Pb varied widely from week to week, but the degree of variation was about a half that of Al. Contrary to Al, the year-to-year variation of 210Pb was not pronounced and its seasonal variation was well expressed by a sine curve. The 210Pb concentration did not show a marked latitudinal variation and its base-line concentration was high in the surface air over the North Pacific. These suggest that atmospheric 210Pb has a longer residence time, due to its transportation through higher altitudes and deposits much more evenly onto the Earth's surface and the ocean, as compared with Al in mineral dust which is larger in size in the source region.  相似文献   

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