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Optimal Forward-Scattering Angles of Atmospheric Aerosols in North China

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Atmospheric and Oceanic Science letters 2014年第3期7卷 236-242页

作者： JIA Sheng-Jie lü da-ren Key laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of Science University of Chinese Academy of Sciences

The accurate understanding of atmospheric aerosol extinction coefficients is very important for at- mospheric science research. To achieve a fast and simple method for determining the parameters, the selection of optimal forward-scattering angles of atmospheric aerosols is required. In this paper, the authors introduce the detec- tion basis of forward-scattering of atmospheric aerosols, and the authors verify the sensitivity of the phase function to the real part of the complex refractive index. The au- thors use the Jaenicke urban aerosol model to determine that forward-scattering angles near 33° are suitable. However, the optimal forward-scattering angles in North China are between 37° and 40°. Numerical simulation shows that certain types of particle size distribution of newly generated particles and pollution have limited in- fluences on the selection of forward-scattering angles. But the ranges of these insensitive angles shift - 10 degrees for dust intrusion, and the relative deviations of the phase function are less than 5.0% within extra angles of 0° to 3°. This study can serve as a reference for the selection of optimal forward-scattering angles for visibility meters and Present Weather Identifiers （PWIs） in addition to the de- tection of forward-scattering optical properties.

关键词： forward-scattering anglesphase function complex refractive index visibility meters

A New Method for Aerosol Retrieval Based on lidar Observations in Beijing

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Atmospheric and Oceanic Science letters 2014年第3期7卷 203-209页

作者： PAN Yu-Bing lü da-ren PAN Weilin Key laboratory of Middle Atmosphere and Global Environment Observation (lAGEO) Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

lidar has been used extensively in the area of atmospheric aerosol *** unknowns at the reference altitude,the lidar ratio and the backscatter coefficient,need to be resolved from the lidar *** the actual application,these two values are difficult to obtain,particularly the backscatter *** better characterize the optical properties of aerosols,optical thickness,and attenuated backscatter obtained by other instruments are usually used as the input for joint ***,this method is limited by location and *** this study,the authors propose a new method for aerosol retrieval by using Mie scattering lidar data to solve this *** authors take the horizontal aerosol extinction coefficient as the constraint to begin the iteration until a self-consistent aerosol vertical profile was *** comparing their results with Aerosol Robotic Network(AERONET) data,the authours determine that the aerosol extinction coefficient obtained by combining horizontal and vertical lidar observations is more precise than that obtained by using the traditional Fernald *** new method has been adopted for retrieving the extinction coefficient of aerosols during the observation days.

关键词： lidarlidar ratiobackward integrationextinction coefficient

Observation and Simulation of Abnormal Transmittance over Yangbajing,Tibet

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Atmospheric and Oceanic Science letters 2014年第3期7卷 190-197页

作者： WANG lei-Di lü da-ren HUO Juan Key laboratory of Middle Atmosphere and Global Environmental Observation (lAGEO) Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

Defining abnormal transmittance as the case where the magnitude of the shortwave flux transmittance is greater than 1.0,the authors used surface solar irradiance and all-sky images obtained at the Yangbajing site in Tibet to analyze the reasons for the occurrence of abnormal shortwave flux *** on the International Intercomparision of Three-Dimensional Radiation Code(I3RC) Monte Carlo community model of three-dimensional radiative transfer,the authors also performed simulations at a nonabsorbing wavelength and an absorbing wavelength through a stratocumulus and a cumulus *** results showed the detection of abnormal transmittance on more than half the days,and the maximum transmittance was *** probability of the occurrence of abnormal transmittance appeared to be largest in summer,and on a daily basis was mainly at about noon local *** transmittance mainly appeared when clear sky and clouds co-existed,especially at the edges of broken clouds and nearby regions with clear-sky *** flux transmittance decreased as the solar zenith angle increased.

关键词： three-dimensional cloudsshortwave flux transmittanceMonte Carlo modelTibet

An Optical Disdrometer for Measuring Present Weather Parameters

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Atmospheric and Oceanic Science letters 2014年第6期7卷 559-563页

作者： JIA Sheng-Jie lü da-ren XUAN Yue-Jian Key laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of Science University of Chinese Academy of Sciences

A new present weather identifier(PWI) based on occlusion and scattering techniques is presented in the study. The present weather parameters are detectable by the meteorological optical range(MOR) approximately up to 50 km and by droplets with diameters ranging from 0.125 mm to 22 mm with velocities up to 16 m s-1. The MOR error is less than 8% for the MOR within 10 km and less than 15% for farther distances. Moreover, the size errors derived from various positions of the light sheet by the particles were checked within ± 0.1 mm ± 5%. The comparison shows that the MOR, in a sudden shower event, is surprisingly consistent with those of the sentry visibility sensors(SVS) with a correlation coefficient up to 98%. For the rain amounts derived from the size and velocity of the droplets, the daily sums by the PWI agree within 10% of those by the Total Rain Weighing Sensor(TRwS205) and the rain gauge. Combined with other sensors such as temperature, humidity, and wind, the PWI can serve as a present weather sensor to distinguish several weather types such as fog, haze, mist, rain, hail, and drizzle.

关键词： present weather parameters present weather identifier precipitation measurement hydrometeor classification meteorological optical range

Verifying Fossil-Fuel Carbon Dioxide Emissions Forecasted by an Artificial Neural Network with the GEOS-Chem Model

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Atmospheric and Oceanic Science letters 2014年第5期7卷 377-381页

作者： WANG Yi-Nan lü da-ren lI Qian PAN Yu-Bing laboratory of Middle Atmosphere and Global Environment Observation (lAGEO) Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

In this study, the authors developed an en- semble of Elman neural networks to forecast the spatial and temporal distribution of fossil-fuel emissions （ff） in 2009. The authors built and trained 29 Elman neural net- works based on the monthly average grid emission data （1979-2008） from different geographical regions. A three-dimensional global chemical transport model, God- dard Earth Observing System （GEOS）-Chem, was applied to verify the effectiveness of the networks. The results showed that the networks captured the annual increasing trend and interannual variation of ff well. The difference between the simulations with the original and predicted ff ranged from -1 ppmv to 1 ppmv globally. Meanwhile, the authors evaluated the observed and simulated north-south gradient of the atmospheric CO2 concentrations near the surface. The two simulated gradients appeared to have a similar changing pattern to the observations, with a slightly higher background CO2 concentration, - 1 ppmv. The results indicate that the Elman neural network is a useful tool for better understanding the spatial and tem- poral distribution of the atmospheric C02 concentration and ft.

关键词： fossil-fuel emissions Elman neural network CO2 concentration GEOS-Chem

Distribution and Variation of Carbon Monoxide in the Tropical Troposphere and lower Stratosphere

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Atmospheric and Oceanic Science letters 2014年第3期7卷 218-223页

作者： lI Qian SHI Hua-Feng SHAO Ai-Mei BIAN Jian-Chun lü da-ren Key laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of Sciences School of Atmospheric Sciences Lanzhou University Troop 93601 The People’s Liberation Army

The authors examine the distribution and varia- tion of carbon monoxide （CO） in the tropics from the sur- face to the lower stratosphere. By analyzing space-borne microwave limb sounder （MlS） measurements, measure- ments of pollution in the troposphere （MOPITT） and mod- em-era retrospective analysis for research and applications （MERRA） meteorological products, and atmospheric chemistry and climate model intercomparison project （ACCMIP） surface emission inventories, the influences of atmospheric dynamics and surface emissions are investi- gated. The results show that there are four centers of highly concentrated CO mixing ratio over tropical areas in differ- ent seasons： two in the Northern Hemisphere and another two in the Southern Hemisphere. All of these centers cor- respond to local deep convective systems and mon- soons/anticyclones. The authors suggest that both deep convections and anticyclones affect CO in the tropical tro- posphere and lower stratosphere--the former helping to transport CO from the lower to the middle troposphere （or even higher）, and the dynamical uplift and isolation effects of the latter helping to build up highly concentrated CO in the upper troposphere and lower stratosphere （UTlS）. Similarly, there are two annual surface emission peaks in- duced by biomass burning emissions： one from the North- ern Hemisphere and the other from the Southern Hemi- sphere. Both contribute to the highly concentrated CO mixing ratio and control the seasonal variabilities of CO in the UTlS, combining the effects of deep convections and monsoons. Results also show a relatively steady emission rate from anthropogenic sources, with a small increase mainly coming from Southeast Asia and lndia. These emis- sions can be transported to the UTlS over Tibet by the joint effort of surface horizontal winds, deep convections, and the Asian summer monsoon system.

关键词： carbon monoxidetropicstropospherelower stratospheresurface emissions

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利用云廓线雷达数据分析云光谱结构特征

光谱学与光谱分析 2013年第4期33卷 911-915页

作者：韩永吕达仁南京大学大气科学学院江苏南京210093 中国科学院大气物理研究所中层大气与全球环境变化实验室北京100029

云在地气系统中扮演着非常重要的角色,当前气候模式的模拟仍然缺乏云体内部精细结构的数据。而用传统的被动卫星辐射计遥感,则会丢失大量的云层垂直分布的信息。正是基于这些原因,NASA提出了CloudSat的发射项目,提供必要的观测以使我们... 详细信息

云在地气系统中扮演着非常重要的角色,当前气候模式的模拟仍然缺乏云体内部精细结构的数据。而用传统的被动卫星辐射计遥感,则会丢失大量的云层垂直分布的信息。正是基于这些原因,NASA提出了CloudSat的发射项目,提供必要的观测以使我们更好的理解云的内部结构。CloudSat于2006年4月28日发射成功,搭载第一个W带(94GHz)云廓线雷达(cloud profile radar,CPR),可提供连续地、全球时间序列的云的垂直结构和特征。利用CloudSat卫星数据对2009年第8号台风云系"莫拉克"和2009年的第15号台风云系"巨爵"进行分析,根据云检测的结果,获取了雷达反射率、云类型以及云层光学厚度的连续变化特征。这将为我们后续台风云系光学特性的研究提供参考。

关键词：大气探测云光谱结构卫星遥感 CloudSat

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GPS无线电掩星技术反演大气参数方法对比

地球物理学报 2007年第2期50卷 346-353页

作者：王鑫吕达仁中国科学院大气物理研究所北京100029

无线电掩星技术是一种探测地球大气的崭新途径.菲涅耳衍射反演是GPS掩星技术中基于物理光学原理的新的反演方法.文章研究了菲涅耳及几何光学方法的反演原理,利用GPS/MET数据分别反演得到了大气折射率及温度廓线.对比分析了菲涅耳衍射方... 详细信息

无线电掩星技术是一种探测地球大气的崭新途径.菲涅耳衍射反演是GPS掩星技术中基于物理光学原理的新的反演方法.文章研究了菲涅耳及几何光学方法的反演原理,利用GPS/MET数据分别反演得到了大气折射率及温度廓线.对比分析了菲涅耳衍射方法在10Hz、25Hz和50Hz三个采样频率下不同的反演结果,通过与几何光学反演结果及相应探空数据的对比分析,表明菲涅耳衍射反演得到的结果在对流层,特别是水汽含量丰富的区域中更为准确可靠.

关键词：无线电掩星菲涅耳衍射大气廓线反演

北京MST雷达探测中间层-低热层观测结果初步分析

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地球物理学报 2016年第2期59卷 440-452页

作者：田玉芳吕达仁中国科学院大气物理研究所中层大气与全球环境探测重点实验室(lAGEO) 北京100029 中国科学院大学北京100049

北京MST雷达是子午工程建设的国内仅有的两部MST雷达之一,为研究其在中间层-低热层MlT区域的探测能力以及数据可靠性,本文应用北京MST雷达2012、2013两年高模式数据,从数据获取率、与廊坊流星雷达测风对比以及风场时空分布特征三个方面... 详细信息

北京MST雷达是子午工程建设的国内仅有的两部MST雷达之一,为研究其在中间层-低热层MlT区域的探测能力以及数据可靠性,本文应用北京MST雷达2012、2013两年高模式数据,从数据获取率、与廊坊流星雷达测风对比以及风场时空分布特征三个方面进行初步分析.结果是：（1）数据获取率日变化特征为：白天65-100km均可获取数据,数据获取率的高值区主要集中在70-80km,最大值可达80%;夜间主要集中在80-100km,数据获取率在30%及以下.表明该MST雷达白天可以探测到电离层D层和E层低层,夜间D层消失,只探测到E层低层.季节变化特征为：夏季白天可获取数据的时间和高度区间都比较大,春季次之,冬季最小.夏季白天以及日落后1h内可探测到120km.（2）对北京MST雷达与廊坊流星雷达2012年5月份、80-100km高度区间测量的水平风进行对比分析,二者测风结果在时空分布上有很好的一致性,表明MST雷达探测数据是可靠的.（3）2012年和2013年相应月份平均的纬向风、经向风时空分布特征有较高的一致性,并与HWM07模式结果也基本一致.上述初步分析结果表明,北京MST雷达对中间层-低热层60-120km高度区域已具备较强的探测能力,所得结果将可用于MlT过程揭示与驱动因子研究,并可与该高度上其他探测手段作综合研究.

关键词：北京MST雷达中间层-低热层探测能力数据可靠性水平风场时空分布特征