Calibration of the 936 nm water-vapor channel for the China aerosol remote sensing NETwork (CARSNET) and the effect of the retrieval water-vapor on aerosol optical property over Beijing, China

Developmental Biology

Tianze Sun²  Quanliang Chen⁵  Guangyu Shi³  Xiaoye Zhang²  Jie Yu⁴  Huizheng Che⁴  Yu Zheng¹  Ke Gui⁴ 

[1] State Key Laboratory of Severe Weather (LASW), Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing, 100081, China$$Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing, 210044, China$$;State Key Laboratory of Severe Weather (LASW), Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing, 100081, China$$;State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China$$;State Key Laboratory of Severe Weather (LASW), Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing, 100081, China$$College of Atmospheric Science, Chengdu University of Information Technology, Plateau Atmospheric and Environment Laboratory of Sichuan Province, Chengdu, 610225, China$$;College of Atmospheric Science, Chengdu University of Information Technology, Plateau Atmospheric and Environment Laboratory of Sichuan Province, Chengdu, 610225, China$$

关键词: CE-318 sunphotometer;    Calibration;    Modified langley method;    CARSNET;    Columnar water-vapor;   

DOI  :  10.1016/j.apr.2016.04.003

学科分类：农业科学（综合）

来源: Dokuz Eylul Universitesi * Department of Environmental Engineering

【 摘 要 】

Based on measurements of the 936 nm water-vapor channel and the 870 nm, and 1020 nm atmospheric window band for the CE-318 sunphotometer of CARSNET, clear-sky direct solar radiation observational data and relative optical air masses of between 2 and 5, and considering sensitivity parameters such as pressure, altitude, wavelength, and AOD_936nm, which may affect the calibration result, a method to calibrate the 936 nm water-vapor channel using a modified Langley method is presented. The daily average columnar water-vapor (CWV) over urban Beijing was retrieved using three methods (Methods A, B and C), and compared with the AERONET water-vapor product. Finally, the seasonal relationships of CWV with AOD_500nm and α_440–870 were analyzed. The calibration results showed the calibration value to differ from the original value by about 4%. The CWV retrieval result showed that AERONET and the three methods of retrieval for CWV were highly correlated. The monthly average variation trends of AOD_500nm and CWV were similar, with the maximum occurring in July, and the minimum in December. The seasonal average variation trends of AOD_500nm and CWV were also similar, but could be placed in the following order: summer > autumn > spring > winter. The seasonal variation of α_440–870 versus AOD_500nm, α_440–870 versus CWV, and AOD_500nm versus CWV, showed increasing AOD_500nm with increasing CWV, which reflected the hygroscopicity of aerosol fine particle growth characteristics. Summer was mainly characterized by fine particles; while spring, autumn and winter were a mix of coarse and fine particles, showing typical urban aerosol properties.

【 授权许可】

Unknown   

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