Calibration and validation of retrieved aerosol properties based on AERONET and SKYNET

This study compares the function of AERONET and SKYNET, which are well known components of the ground-based aerosol-monitoring network. AERONET uses the Cimel CE-318-1 and -2 sun/sky photometer system, and SKYNET adopts Prede POM-01, -02, and -100P sun/sky photometers (aka skyradiometer). These are available for direct- or diffuse-solar radiation measurements in order to calculate aerosol optical thickness or other aerosol properties such as size distribution, respectively. The CE-318-2 (AERONET) and the POM-100P (SKYNET) instruments have recently been installed at Kinki University in Osaka, Japan, for the retrieval of aerosol data. These have been calibrated at NASA/GSFC and at the Mauna Loa Observatory, respectively, based on the Langley plot method. The difference in the aerosol optical thickness derived from simultaneous measurements using these two types of radiometer was less than 0.008 (<4% relative error). Simultaneous observation with AERONET and SKYNET in Osaka allows us to combine AERONET and SKYNET on a global scale. It is of interest that the aerosols over Osaka exhibit quite specific characteristics due to heavy industrial aerosol loading throughout the year and frequent yellow sand events in the spring. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.