National Institute of Environmental Research

The GEO-ring constellation of atmospheric composition missions was established to deliver continuous, diurnally resolved observations of trace gases and aerosols at regional scales. Since the launch of GK2B in 2020, the constellation has expanded to include TEMPO in 2023 and Sentinel-4 in 2025, with additional missions planned. This growing number of operating sensors emphasizes the need for cross-mission consistency and long-term radiometric stability across the GEO-ring framework.As the first GEO-ring sensor, the Geostationary Environment Monitoring Spectrometer (GEMS) onboard GK-2B has been operating for more than five years under harsh space environmental conditions. Over this period, the optical and electronic components of the sensor have experienced degradation of up to 30%, particularly at shorter wavelengths around 300 nm. Given that this sensor has undergone the longest period of degradation, its characterization and correction provide a valuable basis for other GEO-ring sensors with similar instrumental characteristics. In this regard, this study presents post-launch calibration and evaluation methodologies for GEMS with a focus on Level 1 products, including solar irradiance and Earth reflectance. Calibration updates address long-term degradation along with angular dependence and systematic biases of the onboard solar diffuser.For validation of the updates, GEMS is inter-calibrated with both geostationary and low Earth orbit sensors, including the Advanced Meteorological Imager (AMI) onboard the twin satellite GK2A, as well as the Tropospheric Monitoring Instrument (TROPOMI) and Ozone Mapping and Profiler Suite (OMPS). Each reference instrument provides unique strengths in spatial, spectral, and temporal coverage, enabling a comprehensive assessment of GEMS performance. The validation results indicate that the updated GEMS reflectance exhibits spectral biases within 5%, except at wavelengths below 320 nm, where straylight effects dominate.These results demonstrate that the applied calibration and inter-calibration strategies effectively improve the radiometric consistency of GEMS Level 1 products. Building on these approaches, this work highlights the importance of in-flight calibration of Level 1 products for accurate Level 2 retrievals and long-term GEO-ring consistency.

This study evaluated whether compost produced by agricultural residues-mixed livestock manure could improve crop productivity and soil quality while reducing inorganic fertilizer use and nitrous oxide (N₂O) emissions in upland cultivation of autumn Chinese cabbage (Brassica rapa L.). Direct incorporation of crop residues often provides limited benefits due to slow decomposition and nitrogen immobilization; therefore, residues were aerobically co-composted with livestock manure and applied in combination with inorganic fertilizers. The results showed that treatments receiving the agricultural residue–manure compost significantly increased cabbage growth and yield. In particular, the treatment combining compost with 50% the recommended inorganic fertilizer rate produced higher yields than the 100% inorganic fertilizer treatment alone. Compost application improved soil chemical properties, including higher pH, organic carbon, available phosphorus, and exchangeable base cations, and enhanced nitrogen uptake and nitrogen use efficiency. Moreover, cumulative N₂O emissions were reduced by about 21% in the 50% rate inorganic fertilizer plus compost treatment compared with inorganic fertilizer alone. Overall, these findings indicate that co-composted agricultural residues and livestock manure can serve as an effective soil amendment, maintaining high crop productivity while lowering greenhouse gas emissions and reducing reliance on inorganic fertilizers, thereby supporting more sustainable nutrient management in upland cropping systems. Acknowledgments This study was supported by (2026) the RDA Fellowship Program of National Institute of Agricultural Sciences, Research Program for Agriculture Science and Technology Development (Project No. RS-2022-RD010368), Rural Development Administration, Republic of Korea.

The effects of maternal coffee consumption during pregnancy on childhood allergic diseases (ADs) remain insufficiently established. This study aimed to investigate the association between maternal coffee consumption during pregnancy and the risk of ADs in offspring up to 36 months of age. We analyzed data from 3,252 mother-child pairs enrolled in the Korean Children's Environmental health Study (Ko-CHENS). Maternal coffee and caffeine intake were assessed using a food frequency questionnaire. Childhood ADs were identified based on caregiver reports of physician diagnoses. Cox proportional hazards models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), with adjustment for potential confounding factors. Overall, two-thirds (67.5%) of children were reported to have at least one AD, with cumulative incidences at 36 months of age of 47.8% for atopic dermatitis, 23.9% for food allergy, 30.2% for allergic rhinitis, and 2.4% for asthma. Compared with no coffee intake, maternal coffee consumption of <1 serving/day was associated with a reduced risk of atopic dermatitis (HR = 0.89, 95% CI 0.81-0.99, p = 0.045) and food allergy (HR = 0.86, 95% CI 0.74-1.00, p = 0.061). Higher intake (≥1 serving/day) was significantly associated with a lower risk of food allergy (HR = 0.61, 95% CI 0.42-0.88, p = 0.009). No significant associations were observed for asthma or allergic rhinitis. Mild maternal coffee intake during pregnancy may be associated with a reduced risk of specific ADs in early childhood.

This study investigates the formation and accumulation mechanisms of particulate nitrate (NO3-) during haze events in early winter 2021 in Seoul, South Korea, based on intensive ground-based observations from the Satellite Integrated Joint Monitoring of Air Quality (SIJAQ) campaign. Hourly measurements of particulate matter (PM), major PM2.5 components and precursor gases revealed a strong correlation between PM2.5 mass and NO3-, particularly during high-pollution episodes, with synoptic meteorological conditions exerting a dominant influence on NO3- variability. Under anticyclonic conditions, nocturnal gas-to-particle conversion and limited vertical mixing facilitated NO3- accumulation, followed by daytime volatilization at elevated temperatures and enhanced aerosol acidity. In contrast, cold frontal passages promoted rapid and sustained NO3- enhancement through regional transport and vertical entrainment, with elevated concentrations persisting during the subsequent stagnation of the air mass. Thermodynamic analysis indicated that ammonium nitrate formation was favored in both regimes, with ambient precursor levels frequently exceeding equilibrium thresholds. NO3- enrichment coincided with the increase in droplet-mode particles providing volume for secondary formation. Planetary boundary layer height (PBLH) variations further modulated surface concentrations by influencing vertical mixing and dilution. These findings highlight the complex interplay among local chemistry, aerosol microphysics and synoptic meteorology in driving wintertime haze formation in East Asian megacities, with implications for forecasting and mitigation strategies.