Modelling Regional Scale Surface Energy Exchanges And Cbl Growth In A Heterogeneous, Urban-Rural Landscape     

H. A. Cleugh  C. S. B. Grimmond 《Boundary-Layer Meteorology》2001,98(1):1-31

Over the last decade, simple models of theconvective boundary layer (CBL) have beensuggested as an approach to inferring regionallyaveraged land-air exchanges of heat, water and tracegases, because the properties of the CBL respond toan average of the underlying small-scaleheterogeneity. This paper explores the use of anintegral CBL method to infer regionally averagedfluxes in a landscape that has at least three majorsources of heterogeneity – irrigated andnon-irrigated rural land use and a large urban area(Sacramento region, California).The first part of the paper assesses the validity ofthe simple slab model of the CBL – this isintegrated forwards in time using local-scalemeasured heat and water vapour fluxes, to predictmixed-layer depth, temperature and humidity. Of thefour different CBL growth schemes used, the Tennekesand Driedonks model is found to give the bestperformance. Evaluation of the model performancewith different weightings of heat and water vapourfluxes based on the land use characteristics in theregion suggest that the source area for theboundary-layer sonde measurements is larger thanphysically-based estimates would suggest.Finally, measured time series of potentialtemperature are used to infer regionally averagedsensible heat fluxes using an integral CBL (ICBL)method. These ICBL fluxes are compared with thosemeasured at the local scale over the three land usetypes that comprise the region of interest. They arefound to be closest to the heat fluxes calculated byappropriately weighting the measured heat fluxes inthe source area calculated for the ICBL. We concludethat the integral CBL budget method providesadequate estimates of regionally-averaged surfaceheat fluxes in a landscape that is characterised bysurface types with distinctly different surfaceenergy budgets.  相似文献   

THE RELATIONSHIP BETWEEN THE MOVEMENT OF THE MEIYU/BAIU RAIN BELT AND THE PERIODIC NORTHWESTWARD PROPAGATION OF THE CONVECTIVE ACTIVITY FROM TROPICAL WEST PACIFIC     

王亚非  山崎信雄 《Acta Meteorologica Sinica》2001,(3)

In order to investigate the effect of the factors in tower latitudes on Meiyu/Baiu front,adiagnostic analysis for the two cases during June to July of 1985 and 1986 was examined.We foundthat (1)when the tropical convective activity moves westward to 10.5-15.5′N/140°E from eastside of 10.5-15.5°N/160°E,the northward shifts of the Meiyu/Baiu rain belt occurs;(2)themain factor which results in the northward and southward shifts of Meiyu/Baiu rain belt is thoughtas the 8,18 and 30 day oscillations of the tropical convective activity around West Pacific.Meanwhile,the wave train propagating from Lake Baikal via Okhotsk Sea to the tropics couldsometimes shift Baiu rain belt southward;(3)the onsets of Meiyu in China of both cases tend totake place just when the convective activity around lower latitudes moves westward through about140°E with the 8,18 and 30 day oscillation periods firstly coming to June.  相似文献   

THE MESOSCALE CONVECTIVE SYSTEMS ACROSS THE TAIWAN STRAIT AND NEIGHBORING AREAS DURING IOP608 OF HUAMEX     

郑永光  王洪庆  陶祖钰  王立琨 《热带气象学报(英文版)》2001,7(2):154-162

The paper gives the distributions of the daily mean temperature of black body of satellite infrared images from June 7 to 10, 1998 during HUAMEX and examines 14 meso-α-scale convective systems and a number of meso-b-scale convective systems using the satellite infrared images at 1-h intervals. The mesoscale convective systems on June 7 and 9, which resulted in severe rainstorm over the middle of Taiwan and the estuary region of the Pearl River (Zhujiang R.), are emphatically analyzed. The serial development of mesoscale convective systems is revealed by the distributions of the black body temperature of satellite infrared images. The environmental conditions in which many mesoscale convective systems continuously occurred are diagnosed. The visualizing tool, LiveView, displays the link between the upper and lower horizontal wind fields and the vertical circulations and 3-dimensional trajectories of moist air motions, based on the data of objective analyses.  相似文献   

郯庐断裂带的伸展活动及其动力学背景   总被引：106，自引：17，他引：106       下载免费PDF全文

朱光  王道轩  刘国生  宋传中  徐嘉炜  牛漫兰 《地质科学》2001,36(3):269-278

郯庐断裂带的伸展活动发生于晚白垩世至早第三纪,控制形成了-系列断陷盆地.安徽段的断陷出现在晚白垩世至早第三纪,苏鲁段仅发生于晚白垩世,而山东潍坊以北的断陷皆出现在早第三纪,显示了伸展活动南早北晚的迁移规律.这一伸展活动叠加在前期走滑构造之上,呈现为幕式的正断层运动.现可鉴别出断裂带的伸展活动经历过5次显著的断陷事件.郯庐断裂带的伸展构造多不同于典型的裂谷.它与中国东部同期一系列伸展盆地形成的动力学背景一致,是太平洋板块向西正面高角度俯冲下、中国东部岩石圈上拱中出现的巨型伸展构造.  相似文献   

平凉“95．7．19”强对流风暴分析     

董彦雄  陈应元  沈成英 《干旱气象》1996,(2)

分析具有代表性的平凉局地强对流风暴过程，揭示了平凉发生强对流天气独特的地形因素。  相似文献   

冬半年冷空气过程中期预报业务系统   总被引：1，自引：0，他引：1  

任金声  王秀文  王洁颖 《气象》1996,22(1):33-37

介绍了一种以数值预报产品为基础，结合预报经验，运用天气学、统计学、能量学诊断、人工智能和延伸预报等多种技术手段，通过综合决策，制作冷空气过程的中期预报方法。  相似文献   

珠江三角洲工业地域分工研究   总被引：13，自引：2，他引：13  

欧阳南江 《地理学报》1996,51(1):44-50

本文从专业化部门的数量和发展水平以及专业化部门地区分布和组合两方面揭示珠江三角洲工业地域分工的基本特点。指出新形势下虽然不少县市存在专业化部门多而不精，工业结构趋同的问题，但珠江三角洲地域分工格局已开始形成。文章还讨论了形成工业地域分工特点的原因并提出了完善地域分工的措施。  相似文献   

强对流天气发生前期地面风场特征   总被引：5，自引：1，他引：5  

翟国庆  俞樟孝 《大气科学》1992,16(5):522-529

根据对华东地区9次强对流天气的地面风场分析发现,强对流的发生发展与锋前暖区的中尺度辐合线有密切关系,与地面中尺度辐合线相伴的扰动辐合值为-0.8×10~(-4)·s~(-1)左右.当有移动的天气系统与其相遇时,交点附近扰动辐合值迅速增大,促使对流迅猛发展且移速加快.辐合线的形成与大尺度背景和特定地形有关.移动的中尺度辐合线与变压风有关而静正辐合线常与露点锋相伴.  相似文献   

定西防雹增雨试验区对流云活动特征分析     

王鹏祥  王学良  吴国珍 《干旱气象》1995,(2)

用雷达气候学方法，对定西防雹增雨试验区５—９月对流云的地域、日际、强度和传播等特征进行统计分析，得出一些有意义的结论。  相似文献   

一次MCS的尺度分离动能分析          下载免费PDF全文

方慈安  吴宝俊  常国刚  许晨海 《气象》1995,21(11):33-37

利用尺度分离动能方法对１９９４年６月１１日０９ＵＴＣ－１２日１０ＵＴＣ影响湖南省的一次ＭＣＳ进行了研究，结果表明：１．大尺度运动中非地转风以及两种尺度间风场与气压的相互作用产生的动能，是这次ＭＣＳ的主要能源；２．中尺度动能以及两种尺度风场相互作物 动勇，随ＭＣＳ发展而增加；３．在ＭＣＳ的整个发展阶段，高层的总体动能锐减。  相似文献