In order to enhance the capability of monitoring and predicting air quality and climate change over East and Southeast Asia, the National Institute of Environmental Research (NIER) under the Ministry of Climate, Energy and Environment, Korea developed the Geostationary Environment. In order to enhance the capability of monitoring and predicting air quality and climate change over East and Southeast Asia, the National Institute of Environmental Research (NIER) under the Ministry of Climate, Energy and Environment, Korea developed the Geostationary Environment. In order to enhance the capability of monitoring and predicting air quality and climate change over East and Southeast Asia, the National Institute of Environmental Research (NIER) under the Ministry of Climate, Energy and Environment, Korea developed the Geostationary Environment Monitoring. The Geostationary Environment Monitoring Spectrometer (GEMS), launched by the Republic of Korea in February 2020, enables the hourly monitoring of air pollution levels for almost 20 countries in Asia. Specifically, countries covered by the project include Cambodia, the Lao People's Democratic. The Geostationary Environment Monitoring Spectrometer (GEMS) is the first geostationary earth orbit (GEO) environmental instrument, onboard the Geostationary Korea Multi-Purpose Satellite–2B (GEO-KOMPSAT-2B) launched on 19 February 2020, and is measuring reflected radiance from the earth's surface. Our GEMS instrument, which launched in 2020, is helping to improve early warnings for dangerous concentrations of chemicals in our atmosphere across the Asia-Pacific region. A geostationary scanning ultraviolet-visible spectrometer, GEMS is monitoring trans-boundary nitrogen dioxide, sulfur. In 2009, National Institute of Environmental Research (NIER) of the Ministry of Environment, Korea has initiated the Geostationary Environmental Monitoring Spectrometer (GEMS) mission onboard the GEO-KOMPSAT 2B with its launch in 2019., surface in-situ network and Pandora). The GEMS vertical column densities of NO 2 showed reasonable consistency in the spatiotemporal.