排序方式： 共有29条查询结果，搜索用时 15 毫秒
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基于第六次耦合模式比较计划(CMIP6),使用新一代全球模式BCC-CSM2-MR的历史试验和未来共享社会经济路径(SSPs)数据,依据Hadley中心的海表面温度和海冰密集度数据及NCEP/NCAR I再分析资料,评估了BCC-CSM2-MR模式对北极海冰及北极气候的模拟能力,并对未来变化进行了预估.结果表明:BCC... 相似文献
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云中积冰过程微物理参量演变规律的数值模拟 总被引：2，自引：1，他引：1
利用耦合Thompson参数化物理方案的WRF（weather research and forecasting）中尺度数值模式,对发生在2008/2009年和2009/2010年冬季恩施雷达站处三次积冰过程的边界层特征和云雾微物理量进行了模拟,并与实测结果进行了对比分析.模拟结果较好地反映了恩施雷达站上空多逆温影响的温度层结特征;云水质量浓度和云雾滴中值体积直径的模拟值与观测值的平均绝对误差分别为10-2g·m-3和3.8μm;恩施雷达站上空存在一个质量浓度为0.3g ·m-3左右的高值中心,其逐渐下移接地,给积冰过程带来充足水汽,且此时通常也有降雨出现. 相似文献
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Effects of climate change on annual streamflow using climate elasticity in Poyang Lake Basin, China 总被引：2，自引：0，他引：2
Shanlei Sun Haishan Chen Weimin Ju Jie Song Hao Zhang Jie Sun Yujie Fang 《Theoretical and Applied Climatology》2013,112(1-2):169-183
Hydrological processes depend directly on climate conditions [e.g., precipitation, potential evapotranspiration (PE)] based on the water balance. This paper examines streamflow datasets at four hydrological stations and meteorological observations at 79 weather stations to reveal the streamflow changes and underlying drivers in four typical watersheds (Meigang, Saitang, Gaosha, and Xiashan) within Poyang Lake Basin from 1961 to 2000. Most of the less than 90th percentile of daily streamflow in each watershed increases significantly at different rates. As an important indicator of the seasonal changes in the streamflow, CT (the timing of the mass center of the streamflow) in each watershed shows a negligible change. The annual streamflow in each watershed increases at different rates, with a statistically significant trend (at the 5 % level) of 9.87 and 7.72 mm year?1, respectively, in Meigang and Gaosha watersheds. Given the existence of interactions between precipitation and PE, the original climate elasticity of streamflow can not reflect the relationship of streamflow with precipitation and PE effectively. We modify this method and find the modified climate elasticity to be more accurate and reasonable using the correlation analysis. The analyses from the modified climate elasticity in the four watersheds show that a 10 % increase (decrease) in precipitation will increase (decrease) the annual streamflow by 14.1–16.3 %, while a 10 % increase (decrease) in PE will decrease (increase) the annual streamflow by ?10.2 to ?2.1 %. In addition, the modified climate elasticity is applied to estimate the contribution of annual precipitation and PE to the increasing annual streamflow in each watershed over the past 40 years. Our result suggests that the percentage attribution of the increasing precipitation is more than 59 % and the decreasing in PE is less than 41 %, indicating that the increasing precipitation is the major driving factor for the annual streamflow increase for each watershed. 相似文献
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基于新监测指标的江南入梅早晚的气候特征及影响系统分析 总被引：3，自引：0，他引：3
利用中国气象局2014年发布的《梅雨监测业务规定》中的入梅日期资料、NCEP/NCAR再分析资料及NOAA海温资料等,重点研究了1951—2015年江南入梅早、晚的气候特征,及其与同期(5—6月)大气环流及前期海表温度变化的关系。结果表明,近65年来江南入梅日具有显著的年际变化特征,入梅平均日期为6月8日,最早和最晚相差47 d。入梅日主要出现在6月,占80.0%。江南入梅偏早和偏晚年,对流层高层至低层的同期大尺度环流存在明显的差异。入梅偏早年,高层南亚高压和东亚副热带西风急流(西风急流)的建立较早,强度较强,南亚高压北移到青藏高原上空亦偏早,西风急流北跳偏早; 中层中高纬度经向环流较强,而西北太平洋副热带高压(副高)第1次北跳偏早; 低层索马里越赤道气流建立较早,强度较强,西太平洋为反气旋式距平环流; 入梅偏晚年上述环流系统演变特征则基本相反。冬、春季海表温度的异常是影响入梅早、晚的重要的外部强迫因子,也是重要的前期预测信号:当冬季东太平洋海表温度为负距平、澳大利亚东部海表温度偶极子为正位相及春季北大西洋三极子处于正位相时,江南入梅偏早; 上一年12月澳大利亚东侧海表温度偶极子和当年3月北大西洋三极子与江南入梅早、晚关系最为密切,当12月澳大利亚东部海表温度偶极子为正位相时,副高第1次北跳偏早,当3月北大西洋三极子为正位相时,6月西风急流偏强、偏北,有利于江南入梅偏早。 相似文献
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沪宁高速公路一次冬季浓雾过程的数值模拟分析 总被引：2，自引：1，他引：1
利用由多个美国研究部门及大学的共同参与研发的新一代中尺度预报模式和同化系统——WRF（Weather Research Forecast）模式,对2006年12月24—27日沪宁高速公路及其周边地区出现的一次罕见的持续性大雾过程进行数值模拟研究。结果表明,此次大雾过程属于较典型的平流雾,其生成和维持的主要原因是大气层结稳定、系统的下沉运动、充足的水汽;同时也有辐射作用,地面的大气长波辐射冷却是雾维持的重要因素。大范围下沉运动使中低层大气增温与地面辐射降温配合,形成深厚的逆温层,对大雾长时间维持起决定性作用。所以这是一次以平流雾为主伴随辐射雾的过程。27日14时后干冷空气南下才使大雾消散。 相似文献
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The accurate detection of heavy metal-induced stress on crop growth is important for food security and agricultural, ecological and environmental protection. Spectral sensing offers an efficient and undamaged observation tool to monitor soil and vegetation contamination. This study proposed a methodology for dynamically estimating the total cadmium (Cd) accumulation in rice tissues by assimilating spectral information into WOFOST (World Food Study) model. Based on the differences among ground hyperspectral data of rice in three experiments fields under different Cd concentration levels, the spectral indices MCARI1, NREP and RH were selected to reflect the rice stress condition and dry matter production of rice. With assimilating these sensitive spectral indices into the WOFOST + PROSPECT + SAIL model to optimize the Cd pollution stress factor fwi, the dynamic dry matter production processes of rice were adjusted. Based on the relation between dry matter production and Cd accumulation, we dynamically simulating the Cd accumulation in rice tissues. The results showed that the method performed well in dynamically estimating the total amount of Cd accumulation in rice tissues with R2 over 85%. This study suggests that the proposed method of integrating the spectral information and the crop growth model could successfully dynamically simulate the Cd accumulation in rice tissues. 相似文献
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武汉市城市热岛强度非对称性变化 总被引：15，自引：0，他引：15
利用武汉市区气象站及其周边4个县气象站1960-2005年的气温资料,计算了46 a及分时段的季节和年平均气温、平均最高和最低气温倾向率,城市热岛强度倾向率及其贡献率。结果表明：46 a来,城区和郊区的平均气温均以上升趋势为主,最低气温增幅最大,最高气温增幅最小,甚至下降;冬季增幅最快,夏季增幅最慢,甚至下降,这是第一类非对称性。 城市热岛效应也存在增强趋势,以年平均、最低和最高气温表示的城市热岛强度倾向率分别为0.235℃/10 a、0.425℃/10 a和0.034℃/10 a,热岛效应贡献率分别达到60.4%、67.7%和21.8%,这是第二类非对称性。 46 a来的增温和城市热岛强度加强主要是最近23 a快速增温所致,进入本世纪增温进一步加剧。
摘要 计算了武汉市气象站、周边4县气象站平均的1960～2005年间以及前后两半时段四季和年平均、最高、最低气温倾向率,城市热岛强度倾向率和贡献率。结果表明：1）46年来,城区和郊区的平均气温均以增趋势为主,平均气温倾向率为正,最低气温增幅最大,最高气温增幅最小甚至下降,冬季增幅最快,夏季增幅最慢甚至下降,这是第一类非对称性;2）城市热岛效应也存在增趋势,以年平均、最低、最高气温表示的城市热岛强度倾向率分别为0.235、0.425、0.034 ℃/10a,热岛效应贡献率分别达到60.4%、67.7%、21.8%,这是第二类非对称性,3）46年来的增温和城市热岛强度加强主要是后23年快速增温所致,前23年气温变化不明显。武汉市气象站气温资料严重地保留着城市化影响,建议尽快迁站。
关键词 城市热岛强度 最高气温 最低气温 非对称性变化 相似文献
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