High-Resolution PM2.5 Modeling and Respiratory Disease Correlation in Chiang Mai Using Himawari-9 and Ground Observations Katanchalee Taweepornwattanakul and Wataru Takeuchi
Institute of Industrial Science, The University of Tokyo, Japan
Abstract
Haze pollution driven by fine particulate matter (PM2.5) is a recurring environmental and health crisis in Thailand, especially during the dry season. In 2023, Chiang Mai endured one of its most persistent haze events in recent years, with sustained PM2.5 concentrations affecting both residents and tourism. While national air quality trends over the past decade (2015-2024) indicate gradual improvement, annual averages remain above the World Health Organization (WHO) guideline, and seasonal peaks continue to impose acute health risks. This study develops a high-temporal-resolution PM2.5 estimation model by integrating Himawari-9 aerosol optical depth (AOD, Level 2, 10-minute resolution) with ground-based PM2.5 measurements from the Pollution Control Department. Meteorological parameters-air temperature, relative humidity, rainfall, wind speed, and surface pressure-are included as covariates to improve model accuracy. All datasets undergo quality control, spatial reprojection, and subsetting to the Chiang Mai domain before model calibration. Estimated PM2.5 values will be aggregated to monthly means and correlated with monthly respiratory disease statistics, including major conditions such as chronic obstructive pulmonary disease (COPD), asthma, and pneumonia. Using an event-focused ecological design with interrupted time-series analysis, haze months (February-April 2023) will be compared with non-haze months, adjusting for meteorology and seasonality. This preliminary study represents the first integration of high-frequency Himawari-9 AOD, ground PM2.5 data, and monthly respiratory health records in Northern Thailand, offering a scalable framework and initial evidence to support targeted interventions and future multi-year investigations.
Keywords: Himawari-9, PM2.5, AOD, Ground observations, Respiratory health
