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Assessment of Dust Aerosol Optical Depth and Shortwave Radiative Forcing over the Northwest Pacific Ocean in Spring Based on Satellite Observations

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Atmospheric and Oceanic Science Letters 2009年第4期 223-228页

作者： CHEN Lin 1,2.SHI Guang-Yu 1,ZHONG Ling-Zhi 3.and TAN Sai-Chun 1 1 state key {2. of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,chinese academy of Sciences,beijing 10002.,china 2.key {2. of Radiometric Calibration and Validation for Environmental Satellites (KLRCV),National Satellite Meteorology Center,china {13. Administration (NSMC/CMA),beijing,{12.,china 3.state key {2. of severe weather,chinese academy of {13. Sciences,beijing {12.,china state key {2. of Numerical Modeling for Atmospheric Sciences and Geophysical FluidDynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beo＇ing 100029 China key laboratory of Radiometric Calibration and Validation for Environmental Satellites （KLRCV） National Satellite Meteorology Center China Meteorological Administration （SMC/CMA） Beijing 100081 China state key {2. of {3. weather Chinese Academy of Meteorological Sciences Beijing 100081 China

Dust aerosol optical depth (AOD) and its ac-companying shortwave radiative forcing (RF) are usually simulated by numerical ***,by using 9 months of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol product data in combination with Clouds and the Earth’s Radiant Energy System Single Scanner Footprint (CERES/SSF) data,dust AOD and its shortwave RF were estimated over the cloud-free north-west (NW) Pacific Ocean in the springs of 2.04,2.05,and *** results showed that in this region,the mean dust AOD and its shortwave RF were 0.10 and 5.51 W m 2.*** order to validate the dust AOD de-rived by MODIS,results from the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model were also used *** correlation coefficient between the monthly averaged dust AOD derived by MODIS measurements and the model simulation results was approximately *** the estimates of the dust AOD and its shortwave RF obtained in this study are based mainly on satellite data,they offer a good reference for numerical models.

关键词： dust aerosols optical depth shortwave radiative forcing northwest Pacific satellite measurements

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A study on compressive shock wave propagation in metallic foams

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 279-287页

作者： WANG ZhiHua1,2.ZHANG YiFen2.REN HuiLan1 & ZHAO LongMao2.1 {3. key {2. of Explosion Science and Technology,beijing Institute of Technology,beijing 100081,china 2.Institute of Applied Mechanics and Biomedical Engineering,Taiyuan University of Technology,Taiyuan 03.02.,china 1. state key {2. of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China2. Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China

Metallic foam can dissipate a large amount of energy due to its relatively long stress plateau,which makes it widely applicable in the design of structural crashworthiness. However,in some experimental studies,stress enhancement has been observed when the specimens are subjected to intense impact loads,leading to severe damage to the objects being protected. This paper studies this phenomenon on a 2. mass-spring-bar model. With the model,a constitutive relationship of metal foam and corresponding loading and unloading criteria are presented; a nonlinear kinematics equilibrium equation is derived,where an explicit integra-tion algorithm is used to calculate the characteristic of the compressive shock wave propagation within the metallic foam; the effect of heterogeneous distribution of foam microstructures on the shock wave features is also included. The results reveal that under low impact pulses,considerable energy is dissipated during the progressive collapse of foam cells,which then reduces the crush of objects. When the pulse is sufficiently high,on the other hand,stress enhancement may take place,especially in the heterogeneous foams,where high peak stresses usually occur. The characteristics of compressive shock wave propagation in the foam and the magnitude and location of the peak stress produced are strongly dependent on the mechanical properties of the foam material,amplitude and period of the pulse,as well as the homogeneity of the microstructures. This research provides valuable insight into the reliability of the metallic foams used as a protective structure.

关键词： aluminum foam heterogeneous intensive pulse loading stress enhancement

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Post-earthquake assessment of building damage degree using LiDAR data and imagery

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Science china(Technological Sciences) 2008年第S2期51卷 133-143页

作者： LI ManChun1,CHENG Liang1,2.GONG JianYa2.LIU YongXue1,CHEN ZhenJie1,LI FeiXue1,CHEN Gang1,CHEN Dong1 & SONG XiaoGang3.1 Department of Geographic Information Science,Nanjing University,Nanjing 2.0093.{3. 2.state {2. laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 43.079,{3. 3.state {2. laboratory of Earthquake Dynamics,Institute of Geology,{3. Earthquake Administration,{13. 10002.,{3. Department of Geographic Information Science Nanjing University Nanjing 210093 China state key {2. of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China state key {2. of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed *** the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes realistic to identify damages on the scale of individual *** the low accuracy of the results has often led to the use of visual interpretation ***,it is very difficult to estimate the degree of building damage(*** damage,moderate damage,or severe damage) in detail using the existing ***,a novel approach integrating LiDAR data and high resolution optical imagery is proposed for evaluating building damage degree *** approach consists of two steps:3. building model reconstruction and rooftop patch-oriented 3. change ***,a method is proposed for automatically reconstructing 3. building models with precise geometric position and fine details,using pre-earthquake LiDAR data and high resolution ***,focusing on each rooftop patch of the 3. building models,the pre- and post-earthquake LiDAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop *** novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and realize quantitative estimation of building damage degree.

关键词： post-earthquake assessment building damage degree rooftop patch LiDAR imagery

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

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Science china Earth Sciences 2005年第S2期48卷 155-172页

作者： XU Jianming, XU Xiangde, LIU Yu, DING Guoan, CHEN Huailiang, HU Jiangkai, ZHANG Jianchun, WU Hao, LI Weiliang, HE Jinhai, YANG Yuanqin & WANG Jiahe Nanjing University of Information Science & Technology, Nanjing 2.0044, china state {2. laboratory of severe weather, chinese academy of meteorological Sciences, beijing 100081, china meteorological Bureau of Henan Province, Institute of meteorological Sciences, Zhengzhou 450000, china National meteorological Centre of china meteorological Administration, beijing 100081, china National meteorological Information Centre of china meteorological Administration, beijing 100081, china Nanjing University of Information Science & Technology Nanjing 210044 China state key {2. of {3. weather Chinese Academy of Meteorological Sciences Beijing 100081 China meteorological Bureau of Henan Province Institute of Meteorological Sciences Zhengzhou 450000 China National meteorological Centre of china meteorological Administration Beijing 100081 China National meteorological Information Centre of china meteorological Administration Beijing 100081 China

Based on analysis of the air pollution observational data at 8 observation sites in beijing including outer suburbs during the period from September 2.04 to March 2.05, 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 e

关键词： CMAQ-MOS point-area combination emission source influence emission inventory air quality.

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Characteristics of low-frequency oscillations in course of SCS summer monsoon onset

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Acta Oceanologica Sinica 2000年第3期19卷 65-72页

作者：毛江玉谢安宋焱云叶谦 Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Some of the low-frequency oscillation (LFO) characteristics of summer moan onset over the South china Sea (SCS) are examined based on NCEP/NCAR reanalysis data and OLR from NOAA in the period of 1979-1996. It is found that the SCS summer monsoon is characterized by predominance of low-frequency activities with significant interannual variability closely related with onset time. The LFOs over the SCS strengthen after onset. Composite analyses for LFO components of OLR and kinetic energy indicate that the eastward propagation of LFO over the equatorial Indian Ocean and LFO coming from the western Pacific strongly affect the physical processes responsible for the SCS summer monsoon onset. The SCS is the place where the Indian Ocean LFO links with low-frequency activities over the western pacific during summer monsoon onset.

关键词： Low -frequency oscillation the South china Sea summer moan onset

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Photosynthetically active radiation retrieval based on HJ-1A/B satellite data

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Science china Earth Sciences 2010年第S1期53卷 81-91页

作者： LI Li1,XIN XiaoZhou1,SU GaoLi1,2.& LIU QinHuo1 1 state key {2. of Remote Sensing Science,Institute of Remote Sensing Applications,chinese academy of Sciences,beijing 100101,china 2.Zhejiang Climate Center,Hangzhou 3.0017,china 1. state key {2. of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China2. Zhejiang Climate Center Hangzhou 310017 China

Photosynthetically active radiation(PAR) is essential for plant photosynthesis and carbon cycle,and is also important for meteorological and environmental *** advance china's disaster and environmental monitoring capabilities,the HJ-1A/B satellites have been placed in Earth *** of their environmental monitoring objectives is the study of *** simulated direct solar,scattered and environment radiation between 400 and 700 nm under different atmospheric parameters(solar zenith angle,atmospheric water vapor,atmospheric ozone,aerosol optical thickness,surface elevation and surface albedo),and then established a look-up table between these input parameters and *** on the look-up table,we used HJ-1A/B aerosol and surface albedo outputs to derive the corresponding *** of inversed instantaneous and observed PAR values using HJ-1 Heihe experimental data had a root mean square error of 2..2.W m-2.with a relative error of 5.9%.The root mean square error for accumulated daily PAR and observed values was 0.49 MJ m-2.with a relative error of 3.5%.Our approach improved significantly the computational efficiency,compared with using directly radiation transfer *** also studied the sensitivity of various input parameters to photosynthetically active radiation,and found that solar zenith angle and atmospheric aerosols were sensitive PAR *** albedo had some effect on PAR,but water vapor and ozone had minimal impact on PAR.

关键词： Photosynthetically active radiation 6S HJ-1A/B satellites

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Estimation of Sand Transportation Rate for Fixed and Semi-Fixed Dunes Using meteorological Wind Data

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Pedosphere 2009年第1期19卷 129-136页

作者： HU Xia LIU Lian-You LI Shun-Jiang XIAO Bi-Lin LIU Mu-Xin key Lab of Environment Change and Natural Disaster Ministry of Education Beijing Normal Univeristy Beijing 100875 （China） academy of Disaster Reduction and Emergency Management Ministry of Civil Affairs/Ministry of Education Beijing Normal University Beijing 100875 （China） state key {2. of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 21008 （China） Institute of Plant Nutrition and Resources Beijing Academy of Agriculture and Forestry Sciences Beijing 100097 （China） Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 （China）

Taibus County, Inner Mongolia, china, lies in a farming-pastoral ecotone, where severe wind erosion and various aeolian sand hazards are prevalent and fixed and semi-fixed sand dunes occur frequently. This study was conducted to investigate the relationships between sand transportation rate and wind speed for the fixed and semi-fixed sand dunes based on field measurements. The annual quantity of soil erosion by wind was estimated using {2. wind data. The results indicated that the sand transportation rate in Taibus County in 2.00 was 57.3. kg cm-1 year-1 for the semi-fixed dunes and 4.56 kg cm-1 year-1 for the fixed dunes. The total duration of erosive winds covered 12.5% of the time of the year, and spring posed the highest potential of sand transportation. Wind with low speed (≤ 17 m s-1) and high frequency plays a dominant role in sand transportation, while strong wind (≥ 17 m s-1) with low frequency significantly enhanced the sand transportation. Erosive wind speed, directions, and frequency were three crucial dynamic factors influencing sand hazards in the farming-pastoral ecotone. The dominant factors intensifying sand and dust storms in Taibus County might be related to the favorable wind condition in combination with the durable drought, which led to land desertification and vegetation degradation.

关键词： fixed and semi-fixed dunes meteorological wind data sand transportation rate wind erosion

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A MACRO-SCALE SEMI-DISTRIBUTED HYDROLOGICAL MODEL AND APPLICATION TO THE DATONG RIVER VALLEY

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Journal of Hydrodynamics 2005年第6期17卷 667-676页

作者： YANG Zhi-feng LIU Lu-liu SHEN Zhen-yao GORDON G. Huang state key {2. of Water Environmental Simulation School of Environment Beijing Normal Uni- versity Beijing 100875 China National Climate Center Beijing 100081 China Faculty of Engineering University of Regina Canada

A daily distributed hydrological model was developed using routine hydro meteorological data on the basis of the raster DEM and land cover data. Then the model was used to model daily runoff of the Datong River Valley located in the upper catchment of the Yellow River Basin. The runoff comprises surface flow, subsurface flow and ground water flow. Evapotranspiration comprises canopy evaporation, snow sublimation and soil evapotranspiration. The infiltration to the soil was estimated with improved Green-Ampt model, and the potential evapotranspiration is estimated with Morton CRAE method, which only needs the routine meteorological data. Simulation results and the comparison with semi distributed SLURP hydrological model show that the structure of the model presented herein is reasonable.

关键词： hydrological model Yellow River GIS runoff

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Dominant climate factors influencing the Arctic runoff and association between the Arctic runoff and sea ice

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Acta Oceanologica Sinica 2010年第5期29卷 10-20页

作者： LI Pixue ZHANG Zhanhai LIU Jiping Ocean University of china Qingdao 266100 China Polar Research Institute of china Shanghai 200136 China state key {2. of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Shanghai Marine Environmental Monitoring and Forecasting Center Shanghai 200232 China

By using the Arctic runoff data from R-ArcticNET V4.0 and ArcticRIMS,trends of four major rivers flowing into the Arctic Ocean,whose climate factor plays an important role in determining the variability of the Arctic runoff,are *** results show that for the past 3. years,the trend of the Arctic runoff is seasonally *** is a significant trend in spring and winter and a significant decreasing trend in summer,leading to the reduced seasonal *** spring,surface air temperature is the dominant factor influencing the four *** summer,precipitation is the most important factor for Lena and Mackenzie,while snow cover is the most important factor for Yenisei and *** Mackenzie,atmospheric circulation does play an important role for all the seasons,which is not the case for the Eurasian *** authors further discuss the relationships between the Arctic runoff and sea *** negative correlation is found at the mouth of the rivers into the Arctic Ocean in spring,while significant positive correlation is observed just at the north of the mouths of the rivers into the Arctic in *** addition,each river has different relationship with sea ice in the eastern Greenland Sea.

关键词： Arctic runoff multiple linear regressions sea ice

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Typhoon Cloud Image Enhancement by Fuzzy Technique

Typhoon Cloud Image Enhancement by Fuzzy Technique

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第2.届中国气象学会年会灾害天气事件的预警、预报及防灾减灾分会场

作者： Changjiang Zhang1,2. Juan LU1 (1. College of Mathematics, Physics and Information Engineering, Zhejiang Normal University, Jinhua, china 3.0}004 2. state {2. laboratory of severe weather, chinese academy of meteorological Sciences, beijing, china 100081)

A new kind of image measure function is proposed by combing fuzzy theory with other some measures. We use it as the overall fitness function of genetic algorithm to adaptively optimize the nonlinear transform parameters in the nonlinear transform function. Thus an optimal gray transformation curve is obtained to enhance the region of interest for a typhoon cloud image. Experimental results show that the proposed method has higher adaptability and intelligence. The proposed method is better than the classical image enhancement methods in overall performance. Enhanced typhoon cloud images by the proposed method can be used to accurately locate the center and predict intensity of the typhoon.

关键词： typhoon cloud image enhancement genetic algorithm fuzziness

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