Evaluation of the Impact of NO2 in Atmospheric Correction for Surface Reflectance Estimation

The global increase in fine particulate matter, particularly in East Asia, has emphasized the importance of satellite-based monitoring for rapid and extensive observation of atmospheric changes. In South Korea, the Geostationary Environment Monitoring Spectrometer(GEMS) has been deployed to monitor air quality, including aerosol optical depth(AOD). The accuracy of AOD retieval relies significantly on surface reflectance, which is typically estimated using the minimum reflectivity method. However, this approach has limitations as it does not only account for observation geometry conditions(such as SZA, VZA) but also atmospheric conditions such as nitrogen dioxide(NO₂) concentrations, which can significantly influence surface reflectance calculations.

This study aimed to assess the impact of NO₂ concentrations in atmospheric correction for retrieving surface reflectance. By utilizing VLIDORT RTM(Vector Linearized Radiative Transfer Model for the Solution of Inverse Problems), surface reflectance values adjusted for NO₂ were evaluated against those calculated without NO₂ consideration. The results demonstrate that accounting for NO₂ can lead to enhancining the accuracy of surface reflectance retirevals.

The findings of this research suggest the possibility of improving atmospheric correction by considering NO₂ as a factor, in surface reflectance estimation for improved products such as AOD retrieval, ultimately leading to accurate fine particulate matter monitoring. These advancements are expected to contribute to various applied research fields, enhancing the utility of satellite-based environmental monitoring systems like GEMS.

Acknowledgement

This research was supported by Particulate Matter Management Specialized Graduate Program through thet Korea Environmental Industry & Technology Institude(KEITI) funded by the Ministry of Environment(MOE).