Inter-comparison of aerosol optical depth from the Multi-Wavelength Solar Radiometer with other radiometric measurements

Abstract

The Multi-Wavelength Solar Radiometer (MWR), designed and developed in the Space Physics Laboratory, has been extensively used by several research institutions across the country for estimating columnar spectral aerosol optical depth (AOD), the most important parameter needed for assessing the impact of aerosols on regional aerosol forcing. A network of > 30 MWRs is currently in operation under the Aerosol Radiative Forcing over India (ARFI) Project of Indian Space Research Organization’s Geosphere Biosphere Program (ISRO-GBP). This paper reports the results of an extensive inter-comparison of the AODs deduced using the MWR with those obtained from other commercially available instruments, such as a Multi-Filter Rotating Shadowband Radiometer (MFRSR), a calibrated Microtops Sun Photometer (MTOPS) and an EKO Sun Photometer (ESP). The results indicated very good agreement between the AOD derived from MWR with MFRSR, MTOPS and ESP with correlation coefficients of ~ 0.99, 0.88 and 0.92, respectively. This report is intended to serve as a reference document for researchers while using the MWR along with other commercial instruments.