Diurnal variations of anthropogenic sulfur dioxide over Asia observed from GEMS

Sulfur dioxide emissions (SO₂) from coal-fired power plants are known as a major contributor to air pollution. SO₂ emitted into the atmosphere forms sulfate aerosols, leading to acid rain and causing damage to forests. Moreover, exposure to SO₂ in humans can cause eye irritation and affect respiratory health. This study presents the column density variations of anthropogenic SO₂ over Asia using the Geostationary Environment Monitoring Spectrometer (GEMS) onboard the Geostationary Korea Multi-Purpose Satellite-2B (GEO-KOMPSAT-2B). We investigated the diurnal variations of SO₂ emissions from anthropogenic sources, such as coal-fired power plants in India. Retrieved SO₂ columns from GEMS were compared with low-orbit satellites In the GEMS observation area, there was a tendency of low sensitivity in SO₂ retrieval due to scattering by air molecules in the high geometry region, particularly at a high viewing zenith angle (VZA), resulting in high uncertainty in SO₂ retrieval. We discuss these tendencies in detail through an investigation of SO₂ retrieval sensitivity based on concentration and geometry.