Instrument calibration and aerosol optical depth validation of the China Aerosol Remote Sensing Network

Abstract

[1] This paper introduced the calibration of the CE-318 sunphotometer of the China Aerosol Remote Sensing Network (CARSNET) and the validation of aerosol optical depth (AOD) by AOD module of ASTPWin software compared with the simultaneous measurements of the Aerosol Robotic Network (AERONET)/Photométrie pour le Traitement Opérationnel de Normalization Satellitaire (PHOTONS) and PREDE skyradiometer. The results show that the CARSNET AOD measurements have the same accuracy as the AERONET/PHOTONS. On the basis of a comparison between CARSNET and AERONET, the AODs from CARSNET at 1020, 870, 670, and 440 nm are about 0.03, 0.01, 0.01, and 0.01 larger than those from AERONET, respectively. The aerosol optical properties over Beijing acquired through the CE-318 sunphotometers of one AERONET/PHOTONS site and two CARSNET sites were analyzed on the basis of 4-year measurements. It was obvious that the AOD of the Shangdianzi site (rural site) was lower than that of the two urban sites (the Institute of Atmospheric Physics (IAP) site (north urban site) and the Beijing Meteorological Observatory (BJO) site (south urban site)). The AOD of BJO was about 0.05, 0.04, 0.05, and 0.06 larger than that of IAP at 1020, 870, 670, and 440 nm, respectively, indicating that there is more local pollution in the south part of Beijing. The highest AOD was found in summer because of the stagnation planetary boundary layer and transport of pollutants from large pollution centers south of Beijing. The high temperature and relative humidity in summer also favor the production of aerosol precursor and the hygroscopic growth of the existing particles locally, which results in high AOD. In contrast, the lowest AOD at the two urban sites and one rural site in Beijing occurred in winter as the frequent cold air masses help pollutants diffuse easily.

Study of Aerosol Optical Properties Based on Ground Measurements over Sichuan Basin, China

“…The sun-photometer at the Chengdu site is calibrated annually to verify the accuracy and reliability of the data. The calibration procedure has been described by Che et al (2009b).…”

Assessment of In-situ Langley Calibration of CE-318 Sunphotometer at Mt. Waliguan Observatory, China

“…This network, including about 37 stations throughout China, is a routine operation network established in 2002 for the study of aerosol optical property over the different areas in China and for the validation of satellite retrievals. So far, the inter-comparison calibration system has been established in Beijing similar to AERONET at GSFC (Che et al 2009 …”

“…Several international and regional networks of ground-based photometers such as AErosol RObotic NETwork-AERONET (Holben et al 1998), SKYradiometer NETwork-SKYNET (Kim et al 2004;Uchiyama et al 2005), the Global Atmosphere Watch Precision Filter Radiometer-GAW PFR network (Wehrli 2002), and China Aerosol Research Network-CARSNET (Che et al 2009) have been set up over the past 20 years, taking advantage of the development of new instruments and techniques for the systematic observation of optical, microphysical and radiative aerosol properties from the ground.…”

Investigation of the Optical Properties of Aerosols over the Coastal Region at Dalian, Northeast China

“…This study used data from the CE-318 sun photometer installed at Dalian monitoring station, which is calibrated annually using the procedure described by Holben [19], Che [24] and Tao [52] to verify the accuracy and reliability of the data. The CE-318 sun photometer (CIMEL Electronique, Paris, France) in Dalian is the AERONET type of instrument and the measurements include direct solar irradiance by the sun direct channel and the sky radiance by the sky scattering channel.…”

“…Networks of ground-based measurements, such as AERONET [19], PHOTONS [20], AEROCAN [21], SKYNET [22] and EARLINET [23] have been established worldwide, including several automated sites in China. The China Aerosol Remote Sensing NET work (CARSNET) and the Chinese Sun Haze meter Network (CSHNET) were established to derive the optical properties of aerosols from ground-based remote sensing data [24][25][26][27].…”