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

The estimation of the advection diffusion and the optical characteristics of the Asian dust using satellite_level data

利用卫星级数据估计亚洲沙尘的平流扩散和光学特性

基本信息

批准号：
13680611
负责人：
KUSAKA Takashi
金额：
$ 0.58万
依托单位：
Kanazawa Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680611/
关键词：
Asian dust Aerosol MODIS satellite image Advection diffusion Source region of Yellow sand dust Degree of polarization Multi-spectral polarimeter Optical characteristics of Asian dust 長距離輸送シミュレーション黄砂発生源黄砂の光学特性黄砂雲黄砂光学的パラメータ偏光度

项目摘要

The Asian dust (called "Kosa" in Japan) transported from desert areas in the northern part of China often covers over East Asia in the late winter and spring.The Asian dust is also called yellow sand dust.The objectives of this study are to estimate the spatial distribution and the optical characteristics of the Asian dust using the long-range transport model and satellite_level data.The following results were obtained :(1) A method for identifying the released region and time of yellow sand dust using the long-range inverse transport model and MODIS satellite images was proposed. This method was applied to understand Kosa phenomena observed at meteorological stations in Tohoku and Hokkaido districts, Japan on March 17, 2002. As a result, it was found that dust particles were released during about 17 hours from 6h on March 15 in the neighborhood of (43N, 114E).(2) A new algorithm for estimating optical parameters (refractive index, size distribution, optical thickness) of the Asian dust and the surface reflectance simultaneously from ADEOS/POLDER data acquired at a single channel was proposed. Optical parameters of the dust cloud over a desert area and the surface reflectance were estimated inversely from the radiance and polarization data at each of 443nm and 670nm channels. As a result, it was found that the values of parameters estimated at the 443nm channel are almost the same as those at the 670nm channel except for the optical thickness.(3) Polarization measurements of the sky radiation by the multi-spectral polarimeter (PSR-1000) at the ground station in the Kanazawa city, Japan from March to April in 2000 to 2002 have been made. The wavelength dependency of degrees of polarization measured when the hazy dust was recognized in the Kanazawa City was analyzed and it was found that the wavelength dependency for polarization will be due to the size distribution of dust particles transported from the deserts in China.

从中国北部沙漠地区运来的亚洲沙尘（日本称“沙”）经常在冬末和春季覆盖东亚。亚洲沙尘也被称为黄沙尘。本研究的目的是利用长程输运模式和卫星水平资料估计亚洲沙尘的空间分布和光学特征。结果表明：(1)提出了一种利用远程逆输运模式和MODIS卫星影像识别黄沙沙尘释放区域和时间的方法。利用该方法对2002年3月17日日本东北和北海道地区气象站观测到的高沙现象进行了分析。结果发现，从3月15日6时开始，在（43N, 114E）附近的17个小时内，有灰尘颗粒被释放出来。(2)提出了一种利用单通道ADEOS/POLDER数据同时估计亚洲尘埃的折射率、尺寸分布、光学厚度和表面反射率的新算法。利用443nm和670nm通道的辐射和偏振数据反演荒漠地区尘云的光学参数和地表反射率。结果发现，除了光学厚度不同外，443nm通道上的参数估计值与670nm通道上的参数估计值几乎相同。(3) 2000 ~ 2002年3 ~ 4月在日本金泽市地面站用PSR-1000多光谱偏振仪对天空辐射进行了偏振测量。分析了金泽市雾霾沙尘识别时偏振度的波长依赖关系，发现偏振度的波长依赖关系是由中国沙漠输送的沙尘颗粒的大小分布决定的。