High-Resolution PM2.5 Modeling and Respiratory Disease Correlation in Chiang Mai Using Himawari-9 and Ground Observations
Katanchalee Taweepornwattanakul and Wataru Takeuchi

#1Department of Civil Engineering, The University of Tokyo, Tokyo, Japan
#2Institute of Industrial Science, The University of Tokyo, Japan

Abstract

Haze pollution from fine particulate matter (PM2.5) is a major environmental and health concern in Southeast Asia, with northern Thailand heavily impacted by seasonal biomass burning. Chiang Mai experiences recurrent haze episodes each February-April, with concentrations far above health guidelines. Ground monitoring offers direct PM2.5 observations but remains spatially limited. Geostationary satellites such as Himawari-9 provide high-frequency coverage, enabling near-real-time monitoring when calibrated properly. This study, focused on 2023, developed a framework linking Himawari-9 top-of-atmosphere reflectance, AOD retrievals, meteorological factors, and respiratory health outcomes. AOD was retrieved using a 6S-based look-up table and integrated with ERA5 reanalysis in Random Forest models. Seasonal evaluation showed strong predictive skill (R2 = 0.82 during burning, 0.76 in non-haze months), while year-round validation highlighted strong non-stationarity. Monthly exposure estimates correlated with hospital admissions, with asthma and COPD showing significant lagged responses. The framework demonstrates the potential of geostationary satellites for health-relevant air quality monitoring while identifying the need for multi-year and multi-sensor studies.

Keywords: Himawari9, AOD, PM2.5-Modeling, Seasonal Haze Episodes, Respiratory health

Topic: Topic A: General Remote Sensing