权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of estimation method of composition of spatial suspended particulate matters by monitoring of two wavelength lidar

双波长激光雷达监测空间悬浮颗粒物成分估算方法的研制

基本信息

批准号：
14580547
负责人：
TAKEUCHI Nobuo
金额：
$ 2.43万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580547/
关键词：
multiwavelength lidar optical properties of aerosol spatial distribution of aerosol conversion to mass concentration continuous lidar observation fine & coarse component of aerosol chemical component of aerosol 環境計測ライダー浮遊粒子状物質波長依存性

项目摘要

Suspended particulate matter (SPM) is important due to the effect on global warming and air pollution. In a case of urban aerosol, we certified in Chiba the fraction of elemental carbon (EC) is 25% in fine particle (the particle diameter is less than 2 μm) and 9% in coarse particle (the size is larger than 2 μm) by sampling and analysis (Yabuki et al, CLEO 2003). The increase of EC amount brings larger absorption, i.e., larger extinction (scattering + absorption), which means larger lidar ratio S_1 (ratio of extinction to backscattering coefficient). Using the wavelength dependence of aerosol scattering property, we derived the vertical profiles of S_1 parameter and extinction coefficient of urban aerosol only from multi-wavelength lidar observation data. This is based on the lidar signal ratio of adjacent layers at different wavelengths should match the one predicted by Mie scattering theory (Yabuki et al, 2003). If we assume the aerosol model and MEE (mass to extinction efficiency: the inverse of extinction to mass concentration), then the concentration distribution at each altitude van be obtained. In real atmosphere, the aerosol condition changes due to. humidity. So humidity dependence of aerosol properties have been considered. The continuously observed lidar data ad the ground based aerosol concentration data were, compared. Then it is found that the mixture of aerosol in the boundary layer occurs in short period (within one hour) and the conversion coefficient at 532 nm is 0.08 to 0.1 (g/m^3)/(m^<-1>) [MEE : is 10 to 12.5 m^2/g]. This makes it possible to obtain the aerosol spatial profile in the urban boundary layer if the humidity is measured by another method: (Nofel et al, AE, 2004).

悬浮颗粒物（SPM）是重要的，由于对全球变暖和空气污染的影响。在城市气溶胶的情况下，我们在千叶通过采样和分析证明，细颗粒（粒径小于2 μm）中元素碳（EC）的分数为25%，粗颗粒（尺寸大于2 μm）中为9%（Yabuki等人，CLEO 2003）。EC量的增加带来更大的吸收，即，更大的消光（散射+吸收），这意味着更大的激光雷达比S_1（消光与后向散射系数的比）。利用气溶胶散射特性的波长依赖性，仅利用多波长激光雷达观测数据，得到了城市气溶胶S_1参数和消光系数的垂直廓线。这是基于不同波长处相邻层的激光雷达信号比应与Mie散射理论预测的信号比相匹配（Yabuki等人，2003年）。如果我们假设气溶胶模型和MEE（质量消光效率：消光与质量浓度的倒数），则可以获得每个高度货车上的浓度分布。在真实的大气中，气溶胶的状况会因大气中的。湿度因此，考虑了气溶胶特性的湿度依赖性。比较了激光雷达连续观测资料和地基气溶胶浓度资料。结果表明，气溶胶在边界层中的混合是在短时间内（1小时内）发生的，在532 nm处的转换系数为0.08 ~ 0.1（g/m^3）/（m^<-1>）[m：为10 ~ 12.5 m^2/g]。如果用另一种方法测量湿度，这就有可能获得城市边界层中的气溶胶空间分布：（Nofel等人，AE，2004年）。