Study of statistically correcting model CMAQ-MOS for forecasting regional air quality     

XU Jianming  XU Xiangde  LIU Yu  DING Guoan  CHEN Huailiang  HU Jiangkai  ZHANG Jianchun  WU Hao  LI Weiliang  HE Jinhai  YANG Yuanqin  WANG Jiahe 《中国科学D辑(英文版)》2005,48(Z2)

Based on analysis of the air pollution observational data at 8 observation sites in Beijing including outer suburbs during the period from September 2004 to March 2005, this paper reveals synchronal and in-phase characteristics in the spatial and temporal variation of air pollutants on a city-proper scale at deferent sites; describes seasonal differences of the pollutant emission influence between the heating and non-heating periods, also significantly local differences of the pollutant emission influence between the urban district and outer suburbs, i.e. the spatial and temporal distribution of air pollutant is closely related with that of the pollutant emission intensity. This study shows that due to complexity of the spatial and temporal distribution of pollution emission sources, the new generation Community Multi-scale Air Quality (CMAQ) model developed by the EPA of USA produced forecasts, as other models did, with a systematic error of significantly lower than observations, albeit the model has better capability than previous models had in predicting the spatial distribution and variation tendency of multi-sort pollutants. The reason might be that the CMAQ adopts average amount of pollutant emission inventory, so that the model is difficult to objectively and finely describe the distribution and variation of pollution emission sources intensity on different spatial and temporal scales in the areas, in which the pollution is to be forecast. In order to correct the systematic prediction error resulting from the average pollutant emission inventory in CMAQ, this study proposes a new way of combining dynamics and statistics and establishes a statistically correcting model CMAQ-MOS for forecasts of regional air quality by utilizing the relationship of CMAQ outputs with corresponding observations, and tests the forecast capability. The investigation of experiments presents that CMAQ-MOS reduces the systematic errors of CMAQ because of the uncertainty of pollution emission inventory and improves the forecast level of air quality. Also this work employed a way of combining point and area forecasting, i.e. taking the products of CMAQ for a center site to forecast air pollution for other sites in vicinity with the scheme of model products "reanalysis" and average over the "area".  相似文献   

近50年疏勒河流域山区的气候变化及其对出山径流的影响   总被引：3，自引：0，他引：3  

蓝永超  胡兴林  肖生春  文军  王国亚  邹松兵  喇承芳  宋洁 《高原气象》2012,31(6):1636-1644

利用祁连山区水文站和气象站的观测数据,分析了近50年河西走廊西部疏勒河流域山区的气候变化及其对出山径流的影响。结果表明,受全球变暖的影响,疏勒河山区气候持续向暖湿转化,且各季气温均呈持续的上升趋势,山区降水量总体上亦呈增加趋势,年际波动比较剧烈。在各季降水量中,除夏季外其他各季降水量的增加比较显著,海拔3 000m以上中高山地带夏季降水量变化不大,3 000m以下中低山地带夏季降水量略有减少。受山区降水,尤其是3 000m以下中低山地带的降水量显著增加与气温上升所引起的冰雪融水补给的影响,疏勒河出山径流呈持续的增加趋势。由于夏季降水量并未增加,在年径流总量中所占比重最大的夏季径流量的增加主要是由于气温上升所引起的冰雪融水补给的增加所致。  相似文献   

基于数字岩心岩石电性数值模拟方法综述   总被引：2，自引：0，他引：2  

孔强夫  周灿灿  张艳  李霞  李潮流  胡法龙 《地球物理学进展》2015,(2):718-724

以致密砂岩为代表的非常规油气储层,由于具有低孔低渗、孔隙结构复杂及岩心致密等特点导致岩石物理实验测量周期长、成本高、岩心驱替困难,难以定量研究微观参数对电阻率的影响.以X射线CT扫描为基础发展起来的数字岩心岩石物理属性模拟技术则弥补了这种不足.本文系统总结了基于数字岩心电性数值模拟基尔霍夫、随机游走、格子玻尔兹曼、有限元等方法的优缺点;列举了国内外学者的研究实例及取得的进展;探讨了目前电性数值模拟研究中存在的主要问题;同时指出了数字岩心电性数值模拟的发展方向.  相似文献   

    

HU Huiqin  HUANG Fei  ZHANG Shaoqing  RUAN Chengqing  GAO Shanhong  LI Pengyuan 《中国海洋大学学报(英文版)》2019,(2):271-281

Fog has recently become a frequent high-impact weather phenomenon along the coastal regions of North China. Accurate fog forecasting remains challenging due to limited understanding of the predictability and mechanism of fog formation associated with synoptic-scale circulation. One frequent synoptic pattern of fog formation in this area is associated with cold front passage(cold-front synoptic pattern, CFSP). This paper explored the predictability of a typical CFSP fog event from the perspective of analyzing key characteristics of synoptic-scale circulation determining fog forecasting performance and the possible mechanism. The event was ensemble forecasted with the Weather Research and Forecasting model. Two groups of ensemble members with good and bad forecasting performance were selected and composited. Results showed that the predictability of this case was largely determined by the simulated strengths of the cold-front circulation(i.e., trough and ridge and the associated surface high). The bad-performing members tended to have a weaker ridge behind a stronger trough, and associated higher pressure over land and a weaker surface high over the sea, leading to an adverse impact on strength and direction of steering flows that inhibit warm moist advection and enhance cold dry advection transported to the focus region. Associated with this cold dry advection, adverse synoptic conditions of stratification and moisture for fog formation were produced, consequently causing failure of fog forecasting in the focus region. This study highlights the importance of accurate synoptic-scale information for improved CFSP fog forecasting, and enhances understanding of fog predictability from perspective of synoptic-scale circulation.  相似文献   

鄂尔多斯块体北缘中强以上地震活动特征分析   总被引：2，自引：0，他引：2  

戴勇  高立新  胡博  尹战军  赵星 《东北地震研究》2012,28(1):56-62

从阴山地震带6.0级以上地震周期性规律等角度,着重研究了该区域中强以上地震活动特征。阴山地震带6.0级以上强震自公元849年以来,具有百年尺度的周期性特征,1900年之后进入第五活跃期,且当前应变处于较高状态,未来几年内该地震带发生6级以上地震可能性较大。临河—乌海—巴彦浩特地区是7.0级地震的主体空区。ML5.0以上地震具有以东经110°为轴东西对跳特征,东经110°以西地区是新一轮中等以上地震活动的主体区域。1970年以来,发生的6次5.9级以上地震前,均存在ML4.0级以上地震空区或条带。2000年1月1日至2011年9月30日,阴山地震带逐渐形成两条明显的ML4.0级以上地震条带,条带交汇部位所在临河—乌海地区可能是未来发生强震的区域。  相似文献   

无泥型软弱层带的强度参数   总被引：8，自引：2，他引：8  

胡卸文 《山地学报》2000,18(1):52-56

分析表明 ,控制无泥型软弱层带强度参数的主要因素是其物质组成和所赋存的地质环境 (地应力场 )。通过现场和室内完成的大量抗剪试验结果 ,从中建立出强度参数和各控制因素的关系式 ,最终以控制因素的变化规律去揭示软弱层带强度参数的变化规律 ,进而给出不同地段、不同类型软弱层带的强度参数值。  相似文献   

基于城市三维建模技术的文化遗产三维虚拟系统     

胡春霞  张红军  张凤梅  王庆 《现代测绘》2015,(3):30-33

以文化遗产的资源整合和数字化为目的,利用城市三维建模技术,构建文化遗产的真三维虚拟系统,实现对文化遗产的定位、查询、资料上传及下载和遗产景区的定点导览、线路漫游、多媒体展示等功能。以南京云锦文化遗产为例,研究了云锦文化遗产的织造工艺、云锦研究所、馆藏珍宝的三维建模实现以及系统功能的应用开发等问题。  相似文献   

一种基于梯度和与一致性组合策略的无缝纹理映射方法研究     

王一  胡莘  周瑜  陈巍然 《测绘工程》2017,26(11)

针对三维纹理映射中存在接缝、颜色差异大等问题,采用基于梯度值之和的选片算法,结合一致性检查、全局颜色校正和局部颜色校正等策略,消除影像的模糊、重影与色差,实现无缝纹理映射,同时避免影像失焦和障碍物的影响,试验结果表明,该方法纹理映射效果较好。  相似文献   

测井资料在碳酸盐岩储层评价中的应用   总被引：4，自引：0，他引：4  

魏历灵  农社卿  胡国山 《新疆地质》2005,23(1):73-78

以塔河油田碳酸盐岩储集层基本特征为依据,利用常规和能谱测井资料信息比值法和重叠法等技术．致力于储集层缝、孔、洞测井响应特征敏感性评价研究,从中提取8项储层敏感性参数,并对其进行综合评判,确定出划分储层类别的标准,经过50口井的测试资料验证,采用多参数综合评判来划分储层类别是可行的,对储层的评价效果较好,使常规测井资料得到了更深入、广泛的应用。  相似文献   

达里诺尔自然保护区鸟类资源现状及变化分析     

杨凤波  宋丽军  武宏政  胡其图 《湿地科学与管理》2009,5(3):34-37

2006-2008年对内蒙古达里诺尔自然保护区的鸟类资源现状进行了调查研究。新记录鸟类43种,其中重点保护鸟类8种,增加4个新科15属,达里诺尔保护区鸟类达到233种,分属于16目42科113属。国家重点保护鸟类45种,鸟类区系以古北界中的蒙新区、东北区成分为主。主要分布于湿地、草原、沙地疏林和山地4种生态环境。  相似文献