一个植被模式的检验和它在陆气相互作用中的应用   总被引：8，自引：1，他引：7  

薛永康  曾凡荣  Adam C. Schlosser  Samon J. Allen 《大气科学》1998,22(4):575-599

简要介绍了一个植被模式（Simplified Simple Biosphere Model）的发展过程及其在气候研究中的作用。许多观测资料被用来检验和标定这个模式。文中着重介绍了俄罗斯土壤湿度资料和非洲的HAPEX-Sahel观测资料如何帮助我们改进模式和对陆面过程的机制的认识,对观测误差的影响也作了讨论。在地气相互作用中,着重讨论了东亚地气作用的特征。在文中介绍的两个东亚地区的试验中,尽管地面的异常被假设在东亚的两个不同的地区,但都对夏季风传输途径上的降水有很大影响。最后用一个区域模式对陆面模式在预测试验中的应用作了简介。初步的结果显示,这将是一个有很大发展潜力的新领域。  相似文献   

The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) phase 2(c) Red-Arkansas River basin experiment:: 2. Spatial and temporal analysis of energy fluxes   总被引：3，自引：0，他引：3  

Xu Liang  Eric F. Wood  Dennis P. Lettenmaier  Dag Lohmann  Aaron Boone  Sam Chang  Fei Chen  Yongjiu Dai  Carl Desborough  Robert E. Dickinson  Qingyun Duan  Michael Ek  Yeugeniy M. Gusev  Florence Habets  Parviz Irannejad  Randy Koster  Kenneth E. Mitchell  Olga N. Nasonova  Joel Noilhan  John Schaake  Adam Schlosser  Yaping Shao  Andrey B. Shmakin  Diana Verseghy  Kirsten Warrach  Peter Wetzel  Yongkang Xue  Zong-Liang Yang  Qing-cun Zeng 《Global and Planetary Change》1998,19(1-4)

The energy components of sixteen Soil-Vegetation Atmospheric Transfer (SVAT) schemes were analyzed and intercompared using 10 years of surface meteorological and radiative forcing data from the Red-Arkansas River basin in the Southern Great Plains of the United States. Comparisons of simulated surface energy fluxes among models showed that the net radiation and surface temperature generally had the best agreement among the schemes. On an average (annual and monthly) basis, the estimated latent heat fluxes agreed (to within approximate estimation errors) with the latent heat fluxes derived from a radiosonde-based atmospheric budget method for slightly more than half of the schemes. The sensible heat fluxes had larger differences among the schemes than did the latent heat fluxes, and the model-simulated ground heat fluxes had large variations among the schemes. The spatial patterns of the model-computed net radiation and surface temperature were generally similar among the schemes, and appear reasonable and consistent with observations of related variables, such as surface air temperature. The spatial mean patterns of latent and sensible heat fluxes were less similar than for net radiation, and the spatial patterns of the ground heat flux vary greatly among the 16 schemes. Generally, there is less similarity among the models in the temporal (interannual) variability of surface fluxes and temperature than there is in the mean fields, even for schemes with similar mean fields.  相似文献   

Sensitivity of Snowfall Characteristics to Meteorological Conditions in the Yeongdong Region of Korea     

Yoo-Jun KIM  So-Ra IN  Hae-Min KIM  Jin-Hwa LEE  Kyu Rang KIM  Seungbum KIM  Byung-Gon KIM 《大气科学进展》2021,38(3):413-429

This study investigates the characteristics of cold clouds and snowfall in both the Yeongdong coastal and mountainous regions under different meteorological conditions based on the integration of numerical modeling and three-hourly rawinsonde observations with snow crystal photographs for a snowfall event that occurred on 29?30 January 2016.We found that rimed particles predominantly observed turned into dendrite particles in the latter period of the episode when the 850 hPa temperature decreased at the coastal site,whereas the snow crystal habits at the mountainous site were largely needle or rimed needle.Rawinsonde soundings showed a well-defined,two-layered cloud structure along with distinctive wind-directional shear,and an inversion in the equivalent potential temperature above the low-level cloud layer.The first experiment with a decrease in lower-layer temperature showed that the low-level cloud thickness was reduced to less than 1.5 km,and the accumulated precipitation was decreased by 87%compared with the control experiment.The difference in precipitation amount between the single-layered experiment and control experiment(two-layered)was not so significant to attribute it to the effect of the seeder?feeder mechanism.The precipitation in the last experiment by weakening winddirectional shear was increased by 1.4 times greater than the control experiment specifically at the coastal site,with graupel particles accounting for the highest proportion(~62%).The current results would improve snowfall forecasts in complicated geographical environments such as Yeongdong in terms of snow crystal habit as well as snowfall amount in both time and space domains.  相似文献   

密云水库流域土壤侵蚀模数时空动态监测     

郭晴  任永康  陈涛 《地理空间信息》2022,20(5):27-32,76

  相似文献   

展望新世纪努力开创地矿工作新局面     

张永康 《江苏国土资源》2000,25(2)

明确了当前和今后一段时间地矿行政管理、地勘经济发展和科技创新工作的任务.指出:全面推进依法治矿,努力提高矿产资源规划、管理、保护和合理利用水平,加快矿业秩序根本好转的进度,加大地质灾害的防治力度;在地勘队伍属地化的基础上,加大改革调整力度,加速发展地勘经济,加快推进地勘队伍企业化的进程;大力实施科技创新,努力实现地矿科技工作的新突破.  相似文献   

ETM+与SPOT-5Pan融合影像在柯坪推覆构造最新构造变形分析中的应用     

刘华国  冉勇康  陈立春  王虎  董绍鹏 《第四纪研究》2011,31(3):566-576

柯坪逆冲推覆构造系是西南天山最新构造变形的产物,研究其晚第四纪活动性对认识西南天山褶皱-逆断层变形与强震发生的关系有重要的意义.文章通过对柯坪构造系3个典型地点的ETM+和SPOT-5 Pan的处理和分析,解译了这些地点的层状地貌面、活动逆断裂的位置及几何展布,以及活动褶皱的展布形态.通过野外考察,验证了解译的可行性,...  相似文献   

公共气象服务网站数据的及时发布   总被引：3，自引：0，他引：3  

何险峰  蒋丽娟  雷升楷  余华彬  罗永康 《气象科技》2011,39(4):483-488

从公共气象服务网站中内容管理系统的建设出发,介绍了地面气象信息的采集、处理和及时面向网站发布的技术方法和实现方式。网站系统以数据层为核心,对操作层获取的气象信息进行质量控制和统计分析,在完成每小时数据记录入库的同时计算出以日、旬、月、年为时间尺度的记录和相应的气候值。库存的气象信息可以Web方式被公众查询,并经时间序列分析软件和二维GIS图形分析软件处理,可直观表现不同时间尺度下气象要素的现状和历史对比。目前,该系统采用中国2566个自动地面气象观测站提供的数据,为中国天气网、四川气象网、成都公共气象服务网和四川农村信息网提供查询服务,运行良好。  相似文献   

The WAMME regional model intercomparison study   总被引：5，自引：3，他引：2  

Leonard M. Druyan  Jinming Feng  Kerry H. Cook  Yongkang Xue  Matthew Fulakeza  Samson M. Hagos  Abdourahamane Konaré  Wilfran Moufouma-Okia  David P. Rowell  Edward K. Vizy  Seidou Sanda Ibrah 《Climate Dynamics》2010,35(1):175-192

Results from five regional climate models (RCMs) participating in the West African Monsoon Modeling and Evaluation (WAMME) initiative are analyzed. The RCMs were driven by boundary conditions from National Center for Environmental Prediction reanalysis II data sets and observed sea-surface temperatures (SST) over four May–October seasons, (2000 and 2003–2005). In addition, the simulations were repeated with two of the RCMs, except that lateral boundary conditions were derived from a continuous global climate model (GCM) simulation forced with observed SST data. RCM and GCM simulations of precipitation, surface air temperature and circulation are compared to each other and to observational evidence. Results demonstrate a range of RCM skill in representing the mean summer climate and the timing of monsoon onset. Four of the five models generate positive precipitation biases and all simulate negative surface air temperature biases over broad areas. RCM spatial patterns of June–September mean precipitation over the Sahel achieve spatial correlations with observational analyses of about 0.90, but within two areas south of 10°N the correlations average only about 0.44. The mean spatial correlation coefficient between RCM and observed surface air temperature over West Africa is 0.88. RCMs show a range of skill in simulating seasonal mean zonal wind and meridional moisture advection and two RCMs overestimate moisture convergence over West Africa. The 0.5° computing grid enables three RCMs to detect local minima related to high topography in seasonal mean meridional moisture advection. Sensitivity to lateral boundary conditions differs between the two RCMs for which this was assessed. The benefits of dynamic downscaling the GCM seasonal climate prediction are analyzed and discussed.  相似文献   

河套盆地托克托台地湖相层研究   总被引：10，自引：5，他引：5       下载免费PDF全文

李建彪  冉勇康  郭文生 《第四纪研究》2005,25(5):630-639

野外观察表明托克托台地的湖相层与上覆的黄土之间存在风化剥蚀面。文章选择了一个剖面点系统地采集了孢粉样品,同时在湖相层底部、顶部和黄土层底部采集了3个光释光样品;另外在一个观察点的不整合于上新统之上的河流相中采取了一个OSL样品。通过对这些数据结果的分析,并综合已有的地层年代、孢粉数据和水文工程地质钻孔资料,试图取得对托克托台地湖相层形成年代、环境及台地演变过程的合理认识。结果表明:1)湖相层相当于邻区的萨拉乌苏组,形成于12～10万年以前的晚更新世早期;黄土相当于邻区的城川组,形成于8万年之后的晚更新世晚期;形成于3万年左右的湖相层是晚更新世晚期同期沉积黄土相变的结果。2)古气候变化明显,晚更新世早期(12～10万年)气候温和湿润,水量充沛,推测最高湖水位介于海拔1050～1080m之间,在河套盆地形成了一个大湖泊———“河套古湖”,与“萨拉乌苏湖”是分开的;晚更新世晚期(10万年以后)气候干冷,湖水后退,同时意味着黄河开始外流,3万年时期的湖水位为海拔1020m左右。3)上新统地层遭受风化剥蚀使地表处于准平原化,在这一时期和林格尔断裂和鄂尔多斯北缘断裂发生明显位错;约12万年以后,和林格尔断裂停止位错,沉积了晚更新世早期的湖相层,约10万之后湖水向盆地中心退却,并在8万年开始沉积黄土,湖水再也未扩展到台地之上,在这期间鄂尔多斯北缘断裂继续位错直至晚更新晚期大约3万年左右停止,台地最终形成。  相似文献   

我国南方旬降水量的统计特征          下载免费PDF全文

李永康  陆菊中 《热带气象学报》1993,9(2):185-192

本文对秦岭—淮河以南地区旬降水量的时空分布特征进行了初步统计分析。指出论域内各旬降水量大多为正偏态和尖峰态分布。谐波分析表明,旬降水量年变化以1波为主。1波振幅和位相的自然正交分析显示出其年际变化趋势的空间分布各具特色。  相似文献