Analysis of Long-Term Aerosol Optical Properties Combining AERONET Sunphotometer and Satellite-Based Observations in Hong Kong

This study analyzes seasonal characteristics and long-term variations in aerosol optical parameters Hong Kong from 2006 to 2021 using AERONET data satellite-based observations based on the extreme-point symmetric mode decomposition (ESMD) model. The dominant types are mixed aerosols urban/industrial with fine-mode sizes, slightly absorbing or non-absorbing properties. Aerosol depth (AOD), Angstrom exponent (AE) single scattering albedo (SSA) varied seasonally a lower AOD but higher AE SSA summer, elevated spring winter. show year 2012 be turning point, an upward trend before then downwards after 2012. However, for SSA, rising was exhibited both pre- post-2012 periods, larger gradient first period. ESMD analysis shows shorter-term, non-linear fluctuations parameters, alternating increasing declining trends. examination of relationships between meteorological factors extreme boosting (XGBoost) method that effects weather conditions complex non-monotonic. A relative humidity, wind speed southwest directions temperature beneficial abatement loads Kong. In conclusion, findings this enhance understanding properties interactions loading factors.