共查询到19条相似文献,搜索用时 93 毫秒
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中国地表热源的气候学特征 总被引:3,自引:1,他引:3
利用研制的地表热量平衡各分量的气候计算方法,结合全国6个热平衡站资料,计算并讨论了地表热源在全国的分布特征,分析了地面对大气加热的特点以及地表热源的参数化问题。指出季风气候背景、纬度、地形和地表湿润状况是决定地表热源特征的重要因素。就全年来说,在我国湿润、半湿润地区,潜热是地面加热大气的主要形式,西北干燥区则以感热加热为主。 相似文献
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利用遥感地表参数分析上海市的热岛效应及治理对策 总被引:18,自引:5,他引:18
从NOAA-AVHRR数据提取出晴空状况下上海市的地表反照率、地表温度和植被指数参数,分析了冬夏两季遥感地表参数所反映的热岛效应变化。发现在冬夏两季的白天和夜晚都存在明显的城市热岛效应,在冬季夜晚的热岛效应比白天强,而在夏季夜晚的热岛效应比白天弱。这是由于下垫面的差异,导致白天城区地表温度大大超过郊区。城区的地表反照率和植被指数始终小于郊区。进一步的相关分析表明,夏季城市的地表温度与植被指数、地表反照率存在显著的负相关,相关系数分别为-0.975、-0.712。通过提高植被覆盖率和地表反照率,可以减小城市热岛效应。 相似文献
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利用CBERS IRMSS/IRS传感器红外通道数据,基于MODTRAN4和查找表算法,根据地表数字高程和全球/区域一体化数值预报模式,建立相应高度和气象条件下温度反演配套系数,利用CBERS可见/近红外通道和地表比辐射率数据库最终生成地表温度/地表发射率产品.最后介绍了温度产品的验证工作,并对温度反演中存在的参数敏感性和不确定性问题进行了分析. 相似文献
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敦煌绿洲-戈壁过渡带地表辐射与能量特征分析 总被引:8,自引:11,他引:8
利用"西北干旱区陆-气相互作用野外观测试验"2002年在敦煌加强期的资料, 分析了敦煌绿洲-戈壁过渡带的地表辐射和能量特征.研究表明 白天, 绿洲-戈壁过渡带的地表温度和近地层大气温度很高, 和戈壁的地表温度接近;在多数晴天夜晚, 绿洲-戈壁过渡带的地表温度和近地层大气温度要低于戈壁的值.总辐射, 反射辐射和地表长波辐射的值都很接近荒漠戈壁的值, 日积分通量分别为24.48, 6.1, 41.42 MJ*m+-2*d.绿洲-戈壁过渡带的感热、潜热和地表热通量的日积分值分别为6.58, 1.60和0.38 MJ*m+-2*d.同时, 在绿洲-戈壁过渡带有较强的水平湍流输送. 相似文献
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青藏高原地区云对地表净辐射的影响 总被引:8,自引:2,他引:8
利用1982年8月-1983年7月青藏高原地面热源观测实验资料,分析了云量,云状对地表净辐射的影响,计算了与云对地表净辐射强迫作用有关的参数。研究表明:地表净辐射是云量的线性函罢 2对地表净辐射的影响有明显的季节性差异,在春季和夏季,云对地表净辐射的影响非常强烈,并且地表净辐射随云量的增多而减小,在秋季和冬季,云对地表净辐的影响较小,并且地表净辐射随云量的增多百增大。 相似文献
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M. B. Gavrilov 《Meteorology and Atmospheric Physics》1997,62(3-4):141-160
Summary Extended integrations of semi-Lagrangian and Eulerian shallow water primitive equation models are performed. The semi-Lagrangian model used the semi-implicit two-time-level scheme. The Eulerian model used a conserving nonlinear advection scheme.For low resolution and longer integrations, difficulties were encountered with the semi-Lagrangian model which were absent in the Eulerian model. These difficulties are discussed.With 14 Figures 相似文献
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蔡博峰 《气候变化研究进展》2011,7(1):23-28
介绍了国际上城市温室气体清单研究进展。分析了城市清单主流方法体系、模式以及编制原则、边界、范围,并且比较了城市清单和国家清单在方法体系及模式上的差异和其自身特点。重点分析了城市清单编制的“混合模式”和3个尺度范围。最后提出国内城市清单研究面临的困难和建议。 相似文献
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本文对天气导变技术发展的历史作了分期性回顾,指出当前外场云结构探测、实验室试验、数值天气导变模式的拟订、统计效果检验的设计等研究所存在的困难和解决的方法,并提出个人的建议。 相似文献
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概述了地球系统模式和综合评估模型在研究人类活动与气候变化问题上的优势和劣势,明确了将二者进行双向耦合的必要性,客观分析了综合评估模型耦合过程中存在的主要问题,同时系统总结了国际和国内解决耦合难点的主要方法和最新进展,最后分析和讨论了双向耦合模式的不确定性来源和解决方法,为我国进行地球系统模式与综合评估模型双向耦合提供新思路和方法。 相似文献
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Single-channel lidar is a widely used system in atmospheric aerosol and cloud detection. However, many difficulties remain in the automatic and accurate identification of cloud from backscatter signals. Popular methods have been proposed, but there is still large uncertainty in cloud detection, especially when the signal-to-noise ratio is low. In this study, a signal simplification approach based on an improved Douglas-Peucker algorithm is proposed. The layer base and top are then selected using the simplified signal and the raw range-corrected signal. Finally, we use a peak-to-base ratio function to distinguish a cloud layer from a non-cloud layer. The detection results of our algorithm are remarkably better than those obtained using the differential zero-crossing method. 相似文献
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Many difficulties have arisen from top-down approaches to the design and implementation of global environmental initiatives. The concept of translation and other analytical features of Actor-Network Theory (ANT) can offer a way of conceptualising these difficulties and their practical effects. By translation, we refer to what happens in-between the formulation of international goals and the results of implementation, and more specifically, relations and negotiations within this broader process. We examine several aspects of translation in the case of Reducing Emissions from Deforestation and Forest Degradation (REDD+), a prominent global environmental initiative. Using an ethnographic approach, we explore local responses in Central Kalimantan province, Indonesia, to REDD+ ideas and goals that originate at international and national levels. Following selection in 2010 as the official REDD+ pilot province, Central Kalimantan became a site for the convergence of actors and projects with varied sources of funding. The study identifies a central tension that emerged between an initial vision of Central Kalimantan as a pioneer, and local concerns about being used as an experimental subject or ‘guinea pig’ for the testing of externally designed schemes. Results show that greater flexibility in the design of programs and initiatives is needed, to provide space for local inputs. Implementation should pay attention to how local actors are included in planning processes that inform decision-making at higher jurisdictional levels. To bring about intended changes in land use, programs like REDD+ need to extend beyond a focus on short-term projects and targets, to instead emphasise long-term investments and forms of collective action that support learning. 相似文献
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Pastoralists in the Horn of Africa are among the most vulnerable populations to climate change yet little is known about how environmental change shapes their wellbeing and mental health. This paper presents a formative study into the relations between emotion, wellbeing and water security among pastoralist communities in Afar, Ethiopia. It uses focus group and interview data to demonstrate the close relationship between environmental conditions and emotional wellbeing, and shows how current water insecurity leads to extreme worry and fatigue among the studied population, especially in the dry season. In the context of difficulties of translating mental health clinical classifications and diagnostic tools in cross-cultural settings, the paper argues the inductive study of emotion may be a useful approach for studying environmental determined wellbeing outcomes among marginal populations in the light of understanding climate change impacts. 相似文献
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黄达明 《南京气象学院学报》2019,11(5):541-550
区块链本质上的去中心化和安全特性,使得其很适合于解决目前教育领域面临的困难.本文首先介绍了区块链的基本技术原理,包括区块的结构和区块链的构成、区块链技术平台的体系结构、区块链的分类、共识算法、智能合约.接着分析了目前教育领域发展的终身教育和跨地区教育的新形势,以及传统数字化教育系统面临的主要问题.然后从教育相关信息的多方共享和验证、学习过程跟踪、激励和学习路径塑造、学习评估、教育管理与决策辅助等几个方面对区块链技术在教育领域的应用现状进行了介绍和分析.最后总结了目前区块链技术应用到教育领域的主要问题,并展望了未来的发展方向. 相似文献
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RADARSAT数字图像积雪覆盖下地物解译方法 总被引:1,自引:0,他引:1
采用加拿大RADARSAT雷达数字图像,以新疆阿勒泰地区阿勒泰市、布尔津、吉木乃、哈巴河、福海5个县(市)为典型试验区,研究了积雪覆盖下雷达遥感图像地物解译的基本原理和几何纠正方法,比较分析了标准模式的地理参考高分辨率合成孔径雷达图像与经过亮度增强、边缘增强、图像增强、斑点压缩和纹理分析处理的图像上地物目视解译的特点,建立了积雪覆盖下雷达图像上耕地、水系、交通道路、居民地等与抗灾救灾密切相关的地物的解译标志。结果表明,可弥补可见光及近红外遥感积雪监测的缺陷,为雪灾发生区的救援决策提供科学依据。 相似文献