Simulation of a Freezing Rain and Snow Storm Event over Southern China in January 2008 using RIEMS 2.0          下载免费PDF全文

XIONG Zhe 《大气和海洋科学快报》2013,6(1):27-32

The Regional Integrated Environmental Model System(RIEMS 2.0) with NCEP Reanalysis II is utilized to simulate the severe freezing rain and snow storm event over southern China in January 2008,which caused severe damage in the region.The relationships between the freezing rain process and the large-scale circulation,in terms of the westerly and low-level jets,water vapor transportation,and northerly wind area/intensity indices,were analyzed to understand the mechanisms of the freezing rain occurrence.The results indicate the following:(1) RIEMS 2.0 reproduced the pattern of precipitation in January 2008 well,especially for the temporal evolution of daily precipitation averaged over the Yangtze River valley and southern China;(2) RIEMS 2.0 reproduced the persistent trough in the South Branch of the westerlies,of which the southwesterly currents transported abundant moisture into southern China;(3) RIEMS 2.0 reasonably reproduced the pattern of frequencies of light and moderate rain,although it overestimated the frequency of rain in southern China.This study shows that RIEMS 2.0 can be feasibly applied to study extreme weather and climate events in East Asia.  相似文献   

西北太平洋热带气旋潜势分布和年际变率的数值模拟     

田方兴  周天军 《气象学报》2013,71(1):50-62

热带气旋潜势指数是定量表征影响热带气旋生成的大尺度环境条件指标,在不能显式模拟热带气旋的气候系统模式中,常被作为热带气旋的代用指标。基于中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室发展的AGCM GAMIL2.0模式在历史海温驱动下的积分结果,评估了该模式对热带气旋潜势气候态、季节循环和年际变率的模拟能力。并分别从影响热带气旋潜势分布的热力因子(相对湿度、热带气旋最大风速)和动力因子(垂直风切变、绝对涡度、垂直抬升速度)的角度,讨论了造成热带气旋潜势模拟误差的原因。结果表明,在西北太平洋地区,模式能够合理再现热带气旋潜势的气候态分布,但由于GAMIL2.0模拟的相对湿度偏大且向东延伸,造成了热带气旋潜势大值区较之再分析资料偏大且偏东10°。由于GAMIL2.0模拟的季风槽位置偏北偏强,导致模拟的热带气旋潜势季节循环北进偏早而南退偏晚。在年际变化方面,GAMIL2.0能合理模拟出热带气旋潜势在ENSO正负位相东西反向的变化特征,但位于20°—30°N的加强和减弱区的分界线偏西,这与模拟的垂直速度和相对湿度的模拟误差有关,进一步分析表明,这是由于模拟中ENSO事件期间的西北太平洋异常上升中心比观测偏西且偏强造成的。  相似文献   

基于地球系统模式FIO-ESM v2.0对1850~2014年大西洋经向翻转环流变化的研究     

曹茜  董昌明  夏长水 《海洋与湖沼》2022,53(3):538-556

大西洋经向翻转环流(Atlantic meridional overturning circulation,AMOC)作为全球大洋的极向热量输送带,对大西洋附近区域的天气及全球气候变化都存在至关重要的影响。采用自然资源部第一海洋研究所研发的地球系统模式FIO-ESM v2.0(First Institute of Oceanography-earth system model version 2.0)分析了1850~2014年AMOC的空间分布特征及时间变化规律,并进一步讨论造成该变化的可能因素。研究结果表明:1850~2014年AMOC最大值出现在40°N、1 000 m深度附近,其时间序列总体呈现-0.079 1×10⁶ m³/(s·a)的减弱趋势,该期间伴随着Labrador、Irminger海域冬季混合层深度的变浅。通过将模式计算的AMOC强度与RAPID (rapid climate change programme)和OSNAP (overturning in the subpolar North Atlantic program)观测资料进行对比,结合模式间并行比较结果显示该模式能较好地再现观测数据期间的AMOC变化规律。FIO-ESM v2.0模式模拟的AMOC具有55 a左右的年代际周期,Labrador、Irminger海域冬季混合层深度变化揭示的对流变化以及Labrador、GIN海域表层海水密度变化造成的海水下沉对AMOC强度的周期性振荡贡献较明显,其周期性变化与海表盐度(sea surface salinity,SSS)、海表温度(sea surface temperature,SST)、蒸发与降水的差值、北大西洋涛动(North Atlantic oscillation,NAO)等要素的变化密切相关。  相似文献   

Web2.0地图制图的信息生态理论研究     

王世民  赵晶辉  尹章才 《测绘科学》2011,36(4):78-79,42

针对Web2.0地图的开放性和公众参与性给地图信息带来的污染等问题,本文首先总结了地图模型的演化规律,并利用信息生态学原理,结合Web2.0地图的特点,提出地图信息生态概念.在传统地图模型基础上扩展地图信息环境,建立了基于人-图-环境系统的地图信息生态模型,并分析了其特点.从地图信息生态理论的角度,分析了目前主要Web...  相似文献   

Crowdsourcing geospatial data   总被引：6，自引：0，他引：6  

Christian Heipke   《ISPRS Journal of Photogrammetry and Remote Sensing》2010,65(6):550-557

In this paper we review recent developments of crowdsourcing geospatial data. While traditional mapping is nearly exclusively coordinated and often also carried out by large organisations, crowdsourcing geospatial data refers to generating a map using informal social networks and web 2.0 technology. Key differences are the fact that users lacking formal training in map making create the geospatial data themselves rather than relying on professional services; that potentially very large user groups collaborate voluntarily and often without financial compensation with the result that at a very low monetary cost open datasets become available and that mapping and change detection occur in real time. This situation is similar to that found in the Open Source software environment.We shortly explain the basic technology needed for crowdsourcing geospatial data, discuss the underlying concepts including quality issues and give some examples for this novel way of generating geospatial data. We also point at applications where alternatives do not exist such as life traffic information systems. Finally we explore the future of crowdsourcing geospatial data and give some concluding remarks.  相似文献   

基于Web 2.0的边与节点同时增长网络模型     

熊菲  刘云  司夏萌  丁飞 《海洋学报》2010,32(10):6889-6895

模拟了Web 2.0网络的发展过程并研究其拓扑结构,分析某门户网站实际博客数据的度分布、节点度时间变化,发现与先前的无标度网络模型有所差别. 根据真实网络的生长特点,提出了边与节点同时增长的网络模型,包括随机连接及近邻互联的网络构造规则. 仿真研究表明,模拟的网络更接近实际,在没有优先连接过程时,模型能得到幂率的度分布; 并且网络有更大的聚类系数以及正的度相关性.  相似文献   

Robust control for an autonomous underwater vehicle that suppresses pitch and yaw coupling     

Jan Petrich 《Ocean Engineering》2011,38(1):197-204

Attitude control systems for autonomous underwater vehicles are often implemented with separate controllers for pitch motion in the vertical plane and yaw motion in the horizontal plane. We propose a novel time-varying model for a streamlined autonomous underwater vehicle that explicitly displays the coupling between yaw and pitch motion due to nonzero roll angle and/or roll rate. The model facilitates the use of a multi-input multi-output H_∞ control design that is robust to yaw-pitch coupling. The efficacy of our approach is demonstrated with field trials.  相似文献   

Web2.0地图的双向地图信息传递模型     

尹章才 《武汉大学学报(信息科学版)》2012,37(6):733-736

在柯拉斯尼模型的基础上,借助因特网通信体系的分层方法,提出了Web 2.0地图作为空间信息平台的双向传输体系,丰富和完善Web 2.0环境下的地图信息传递理论。  相似文献   

采用USB2.0接口的数据采集系统     

韩斌  方睿 《成都信息工程学院学报》2007,22(3):324-326

阐述了基于USB2.0总线的高速A/D数据采集系统的工作原理和结构,以及设备固件程序、应用程序的设计和实现.  相似文献   

基于JavaScript的WebGIS地图发布原理与应用     

郑丽娜  邱儒琼 《测绘科学》2008,(Z1)

本文介绍了一种新的WEBGIS实现模式和技术,利用JavaScript库提供给客户端浏览器地图应用接口,详细描述了地图库的核心算法;同时介绍了JavaScript地图库在湖北省电子政务空间基础地理信息系统中的实际应用。  相似文献