共查询到20条相似文献，搜索用时 61 毫秒
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江西贵溪市近50年气候特征分析 总被引：2，自引：2，他引：2
利用1953—2002年贵溪市国家一级站的气象资料,分析了近50 a贵溪市气温、降水、日照的变化特征。分析结果表明,贵溪市年、冬季气温呈上升趋势,而夏季气温呈下降趋势,20世纪90年代冬季增温最为明显;年降水总体呈略上升趋势,90年代降水量异常偏多;年日照时数总体呈下降趋势。分析结果还表明,贵溪市气候正在趋向变暖,特别是近10 a来气温升高明显。 相似文献
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基于GIS的流域数字划分方法研究 总被引：4，自引：2，他引：4
利用TOPAZ软件和江西省1:25万地理数据,以贵溪市为例,对河网的生成和流域的划分进行了试验。结果表明:通过采用“burn-in”算法,可以生成与实际较为吻合的河网及流域界限,能够满足目前气象部门开展流域降水预报工作中流域划分的需要。 相似文献
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近几年,小拱棚甘蓝（春甘蓝）～夏玉米间作套种在豫北地区种植面积逐渐扩大,许多菜农种植早熟春甘蓝走上了致富路。但是部分菜农为单纯追求甘蓝早熟,早上市,卖个好价钱,播期越来越早,再加上管理不当,早熟春甘蓝先期抽苔现象普遍发生,在濮阳地区尤以１９９５年为重... 相似文献
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根据弥渡县农业技术推广中心多年的观测试验资料,分析了冬早熟大蒜叶枯病流行的规律与气象条件的关系,发现病害与种植区域、种植年度、播期早迟、降雨过程和日照有关。初步提出防治的主要措施,供冬早熟蒜区参考。 相似文献
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根据上饶市气候资源优势,结合土壤特点,对上饶市天桂梨种植适宜区进行了分析,并提出了天桂梨栽培过程中需要注意的问题。 相似文献
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册亨县早熟蔬菜种植的气候发展前景分析 总被引：2，自引：0，他引：2
通过对册亨县气象站记录的39 a观测资料,从光、热、水和气象自然灾害等多个方面进行分析,寻找出适宜册亨县早熟菜蔬种植的气候指标,充分利用册亨县的气候资源,促进其早熟蔬菜产业的发展。规划出册亨县早熟蔬菜的最佳适宜种植区域和一般性适宜种植区域。 相似文献
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1983年我地区从辽宁省农科院引进了早熟油葵辽葵一号、辽葵杂一号和辽葵杂二号新品种。经过多年的试验、示范和推广,证明辽葵杂二号具有增产的良种优势,可以在哈密推广种植。一、哈密气候适宜辽葵杂二号种植 相似文献
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高寒地区玉米高产栽培技术田军，郭志锋，李振友，程宝华１前言北安地区位于４７°５３′～４８°３３′Ｎ之间，属高寒地区，无霜期短，积温少，只能种植早熟及极早熟玉米，且产量低。１９９２～１９９３年进行玉米营养液育苗移栽试验示范，引入中早熟玉米获得高产，营养... 相似文献
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以一些易被忽略、简化的指示性云状及编码为依据,论述云天演变,对于观测、记录及编码具有重要意义。 相似文献
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就百色工业立市的情况作简要概叙,并在工业立市进程中,除了决策和公益气象服务以外,气象信息服务的市场前景、营销人员队伍、服务中应注意的事项及气象信息服务的可能服务对象和内容作了较为详细的探讨。 相似文献
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综合布线系统采用标准化的语音、数据、图像、监控设备,各线综合配置在一套标准的布线系统上,统一布线设计、安装施工和集中管理维护。综合布线系统在广东省气象局核心网络升级综合布线实际应用效果明显。 相似文献
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综合布线系统在气象核心网络升级中的应用 总被引：11，自引：0，他引：11
综合布线系统采用标准化的语音、数据、图像、监控设备，各线综合配置在一套标准的布线系统上，统一布线设计、安装施工和集中管理维护。综合布线系统在广东省气象局核心网络升级综合布线实际应用效果明显。 相似文献
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The Impact Of Air-Flow Separation On The Drag Of The Sea Surface 总被引：2，自引：1，他引：2
An approach that allows assessment ofthe impact of air-flow separation (AFS) fromwave breaking fronts on the sea-surface drag is presented. Wave breaking fronts are modelled by the discontinuities of the sea-surface slope. It is assumedthat the dynamics of the AFS from wave breaking crests is similar to thatfrom the backward facing step. The form drag supported by an individualbreaker is described by the action of the pressure drop distributed alongthe forward face of the breaking front. The total stress due to the AFS isobtained as a sum of contributions from breaking fronts of different scales.Outside the breaking fronts the drag of the sea surface is supported by theviscous surface stress and the wave-induced stress. To calculate the stressdue to the AFS and the wave-induced stress a physical model of the wind-wavespectrum is used. Together with the model of the air flow described in termsof surface stresses it forms a self-consistent dynamical system for the seasurface-atmosphere where the air flow and wind waves are strongly coupled.Model calculations of the drag coefficient agree with measurements. It is shownthat the dimensionless Charnock parameter (roughness length normalized onthe square of the friction velocity and the acceleration of gravity)increases with the increase of the wind speed in agreement with fieldmeasurements. The stress due to the AFS normalized on the square of thefriction velocity is proportional to the cube of wind speed. At low windsthe viscous surface stress dominates the drag. The role of the form drag,which is the sum of the stress due to the AFS and the wave-induced stress, isnegligible. At moderate and high winds the form drag dominates. At windspeeds higher than 10 m s-1 the stress supported by the AFS becomescomparable to the wave-induced stress and supports up to 50% of the totalstress. 相似文献
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黑潮OLR距平指数与华南西部主汛期降水的关系 总被引：1，自引：0，他引：1
OLR距平场与华南西部主汛期降水的相关分析场显示,在黑潮区域有强烈的高相关信号反映。黑潮区OLR距平指数与华南主汛期降水的遥相关分析显示,前期黑潮区OLR距平指数的异常,可以成为预测主汛期降水有一定指示意义的前兆信号。并在此基础上建立主成分降维分析方法,对1989~2000年主汛期降水作预测及回代检验,检验结果准确率达75%,说明用黑潮区OLR距平指数作为预报因子可以取得良好的预报成绩。 相似文献
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Releases of halocarbons into the atmosphere over the last 50 years are among the factors that have contributed to changes in the Earth’s climate since pre-industrial times. Their individual and collective potential to contribute directly to surface climate change is usually gauged through calculation of their radiative efficiency, radiative forcing, and/or Global Warming Potential (GWP). For those halocarbons that contain chlorine and bromine, indirect effects on temperature via ozone layer depletion represent another way in which these gases affect climate. Further, halocarbons can also affect the temperature in the stratosphere. In this paper, we use a narrow-band radiative transfer model together with a range of climate models to examine the role of these gases on atmospheric temperatures in the stratosphere and troposphere. We evaluate in detail the halocarbon contributions to temperature changes at the tropical tropopause, and find that they have contributed a significant warming of ~0.4 K over the last 50 years, dominating the effect of the other well-mixed greenhouse gases at these levels. The fact that observed tropical temperatures have not warmed strongly suggests that other mechanisms may be countering this effect. In a climate model this warming of the tropopause layer is found to lead to a 6% smaller climate sensitivity for halocarbons on a globally averaged basis, compared to that for carbon dioxide changes. Using recent observations together with scenarios we also assess their past and predicted future direct and indirect roles on the evolution of surface temperature. We find that the indirect effect of stratospheric ozone depletion could have offset up to approximately half of the predicted past increases in surface temperature that would otherwise have occurred as a result of the direct effect of halocarbons. However, as ozone will likely recover in the next few decades, a slightly faster rate of warming should be expected from the net effect of halocarbons, and we find that together halocarbons could bring forward next century’s expected warming by ~20 years if future emissions projections are realized. In both the troposphere and stratosphere CFC-12 contributes most to the past temperature changes and the emissions projection considered suggest that HFC-134a could contribute most of the warming over the coming century. 相似文献
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The flux-gradient model, often used to describe turbulent dispersion, implicitly defines an eddy diffusion coefficient K that is known to be related to the Eulerian probability density function (pdf) of the turbulent velocity field. In the strict limit of applicability of Fick's law, the relationship between K and the pdf is used to investigate the influence of non-Gaussianity on dispersion in homogeneous turbulence. A bi-Gaussian pdf is used as a closure model that allows for separate studies of skewness and kurtosis variations. The choice of model parameters can have a significant influence on K, especially when the pdf is bimodal. Both arbitrariness of the closure and bimodality are then reduced using the maximum entropy criterion for the selection of the free parameter of the closure scheme, together with the assumption that the model is valid only for those values of the parameters for which a unimodal pdf is possible. The variations of K are found to be sensitive to both skewness and kurtosis showing a more complex behaviour than that found in literature. 相似文献