Parsivel~激光降水粒子谱仪及其在气象领域的应用     

濮江平  赵国强  蔡定军  姚展予  袁冬梅  吕梅 《河南气象》2007,(2)

降水粒子特性是大气运动和云内微物理过程的综合结果,在云降水物理及人工影响天气领域有着重要的意义。传统的测量方法不适合对大量数据分析寻找规律,德国OTT公司的Parsivel激光降水粒子谱测量系统可以较好解决自动测量难题。该仪器是以激光测量为基础的粒子测量传感器,采用平行激光束和光电管阵列结合,当有降水粒子穿越采样空间时,自动记录遮挡物的宽度,通过穿越时间计算降水粒子的尺度和速度,根据各种参数的综合信息对降水粒子进行分类,并能够以数字形式显示瞬时降水强度、降水粒子总数、累积降水量、降水时的能见度和雷达反射因子,以图形方式显示降水粒子尺度谱、速度谱、降水粒子分类且自动生成天气现象代码,实现天气现象的自动识别。激光降水粒子谱仪主要用于气象水文观测。在雷达气象学领域可用于Z/R关系的拟合修正,比传统的用雨量筒观测数据拟合效果好得多;由降水粒子谱仪测量雨滴的降落速度,可以对天气雷达垂直向上测量的粒子径向速度谱进行校正。人工影响天气的效果检验一直是一个难题,自然降水粒子谱分布形式与人工催化以后的降水粒子谱型理论上应当具有较大的差别,人工增雨作业降水滴谱变化物理响应和降水强度时间变化响应都有明显的区别。如果能够实时检测到这些差别,就能够充分说明人工催化的有效性。未来如果能够进行联网观测记录区域性降水、降雹,就有充分证据表明人影作业的有效性,在定量化作业效果评估以及灾害损失评估等方面应用潜力巨大。利用该仪器已经对一年的自然降水过程进行了连续观测,并将所获得的降水粒子谱、雨滴浓度值随时间变化状况与卫星反演的云顶有效粒子半径时间变化趋势进行了对比,发现有较好的一致性。  相似文献   

焦作市农业气候资源及变化特点     

闫小珍  李伟  赵海军  杨来松 《河南气象》2007,(2)

焦作市的农业气候资源丰富,雨热同季,并有不完全同步的特性,10℃以上活动积温为4653~4960℃.d,降水量为548.8~590.5 mm,主要分布在4-10月,日照时数2107.5~2444.9 h。近40 a热量资源呈增多趋势,20世纪90年代的热量资源明显多于前30 a,水分变化不明显,日照时数呈递减趋势。  相似文献   

山东省近40a来的气温和降水变化趋势分析   总被引：19，自引：5，他引：19  

徐宗学  孟翠玲  赵芳芳 《气象科学》2007,27(4):387-393

本文利用非参数检验法(Mann-Kendall法)分析了山东省15个站点近40 a(1958—1998)来气温和降水的长期变化趋势。结果表明:全省气温除西南的莘县、兖州有下降趋势外,大部分地区呈现上升趋势,全省平均上升0.06℃/10a。分季情况为:春季和冬季气温有上升趋势,其中冬季气温上升对全省气温上升的贡献率最大。夏季气温基本保持不变,秋季气温有下降趋势。全省除济南降水量呈略微上升趋势外,其余地区的降水倾向率均为负值,全省的降水倾向率为-3.05 mm/a。表明山东省自1960年以来,年均降水量呈现减少趋势。减少幅度东南部大于西北部,以东南沿海平均减少幅度最大。  相似文献   

Study on cut-off low-pressure systems with floods over Northeast Asia   总被引：4，自引：0，他引：4  

Sixiong Zhao  Jianhua Sun 《Meteorology and Atmospheric Physics》2007,96(1-2):159-180

Summary The cut-off lows (COLs) during the period from June to August 1998 leading to the record flood in Northeast Asia, especially in Northeast China, has been investigated in this paper. The results are as follows: the blocking highs benefited significantly the formation and maintenance of COLs over Northeast China; an obvious frontogenesis zone existed in Northeast China and it implies that baroclinity played an important role in the initiation of COLs, especially in middle and upper troposphere; the maxima of the potential vorticity anomaly were located in the upper troposphere, then extended downwards to the middle and the lower troposphere. The pronounced interaction between systems in upper-middle and low troposphere can be revealed; the moisture supply was from South China, and even from East China Sea and South China Sea. The strong southerly current transported very rich moisture to Northeast China. The maximum of the convergence of moisture flux was below 850 hPa. Obvious interaction between the middle and lower latitude systems was found in the study. Also, the summer monsoon showed significant impacts on the sustained heavy rainfalls related with the COLs over Northeast China; the upward motion could be caused by the lifting of the large scale dynamic forcing and there was no obvious releasing of latent heating in the upper-middle troposphere. The cold dome in the COLs was quite different both from the warm core in tropical cyclone and from the weaker warm core in Meiyu (Baiu) front low. The calculation of vorticity budget shows that both the horizontal advection term and horizontal divergence term contributed importantly to the maintenance and the strengthening of positive relative vorticity. Finally, the complex dynamical characteristics regarding the COLs are discussed and further investigation is proposed.  相似文献   

Initialization and simulation of a landfalling typhoon using a variational bogus mapped data assimilation (BMDA)   总被引：2，自引：0，他引：2  

Y. Zhao  B. Wang  Y. Wang 《Meteorology and Atmospheric Physics》2007,98(3-4):269-282

Summary Recently, a new data assimilation method called “3-dimensional variational data assimilation of mapped observation (3DVM)” has been developed by the authors. We have shown that the new method is very efficient and inexpensive compared with its counterpart 4-dimensional variational data assimilation (4DVar). The new method has been implemented into the Penn State/NCAR mesoscale model MM5V1 (MM5_3DVM). In this study, we apply the new method to the bogus data assimilation (BDA) available in the original MM5 with the 4DVar. By the new approach, a specified sea-level pressure (SLP) field (bogus data) is incorporated into MM5 through the 3DVM (for convenient, we call it variational bogus mapped data assimilation – BMDA) instead of the original 4DVar data assimilation. To demonstrate the effectiveness of the new 3DVM method, initialization and simulation of a landfalling typhoon – typhoon Dan (1999) over the western North Pacific with the new method are compared with that with its counterpart 4DVar in MM5. Results show that the initial structure and the simulated intensity and track are improved more significantly using 3DVM than 4DVar. Sensitivity experiments also show that the simulated typhoon track and intensity are more sensitive to the size of the assimilation window in the 4DVar than that in the 3DVM. Meanwhile, 3DVM takes much less computing cost than its counterpart 4DVar for a given time window.  相似文献   

Roles of Mesoscale Terrain and Latent Heat Release in Typhoon Precipitation： A Numerical Case Study     

李昀英  黄伟  赵焦枝 《大气科学进展》2007,24(1):35-43

The mesoscale orographic effects on typhoon Aere＇s precipitation are simulated using an Advanced Regional Eta-coordinate Model （AREM） version 3.0. In particular, the effects of the latent heat release are studied by two comparable experiments： with and without condensational heating. The results show that the typhoon rainfall is tripled by the southeastern China mesoscale terrain, and the condensational heating is responsible for at least half of the increase. One role of the latent heat release is to warm the atmosphere, leading to a depression of the surface pressure, which then causes a larger pressure difference in the zonal direction. This pressure gradient guides the water vapour to flow into the foothills, which in turn amplifies the water vapour flux divergence amplified, causing the typhoon rainfall to increase eventually. The other role of the latent heat release is to make the convection more organized, resulting in a relatively smaller rain area and stronger precipitation.  相似文献   

"龙王"(LONGWANG)台风过程湿位涡的诊断分析   总被引：8，自引：2，他引：8       下载免费PDF全文

赖绍钧  何芬  赵汝汀  沈桐立  吴启树 《气象科学》2007,27(3):266-271

本文应用MM5V3中尺度数值模式对0519号台风“龙王”过程进行了数值模拟,利用模拟结果计算了台风过程湿位涡(Moist Potential Vorticity,MPV)的演变,从湿位涡的角度研究了台风过程大暴雨的产生机制。结果表明:倾斜涡度发展是“龙王”台风在福建沿海产生大暴雨的重要机制之一,湿位涡能够对暴雨落区的预报有较强的指示性作用,暴雨产生在θse线陡立的对流层中低层MPV1等值线密集带中零线附近,对流层中高层的MPV2负值区可以作为暖湿气流或涡旋活动的示踪;另外,对流层中高层中高纬度冷空气扩散南下与台风的东南暖湿空气在福建沿海交汇,加剧了气旋性涡度发展,对暴雨的发生发展也有巨大的作用。  相似文献   

京津冀地热资源综合利用研究     

田勇  王卫民  赵岩 《中国煤炭地质》2020,(2):51-58

京津冀地区资源环境问题,需发挥地质工作基础先行作用—积极拓展清洁能源领域,在大气治理行动中发挥作用。京津冀地区地热资源丰富,地热资源主要为沉积盆地型地热资源,占总量的99%。沉积盆地型地热资源主要分布在新近系明化镇组、馆陶组,古近系东营组,寒武-奥陶系,元古界。对京津冀地下热水进行科学合理的开发,将资源优势转化为经济优势和生态优势,是我省乃至京津冀发展低碳经济、绿色经济的迫切需要,是实现节能减排目标的有效途径。  相似文献   

中国萤石产业资源现状及发展建议     

赵鹏  郑厚义  张新  王帆  王英林 《化工矿产地质》2020,42(2):178-183

萤石是中国重要的战略性矿产资源。本文通过分析萤石资源现状、供需格局、产业发展以及近年来萤石行业发展面临的新形势和特点,为保障中国萤石产业可持续发展提出加大勘查投入、提高资源保障程度、合理有效开发、促进产业升级等建议。  相似文献   

Florogeography of mire plants in southern part of qinghai-xizang plateau and its adjacent areas     

赵魁义 《中国地理科学(英文版)》1998,8(1):44-52

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