Analysis of Aerosol Dehumidification Efficiency Using the Dry Air Dilution Method at Anmyeon-do

해안지역 에어로졸 관측 시 건조공기 희석 방식의 제습 효과 분석

This study evaluates the efficiency of dry air dilution method as an alternative to traditional heating methods for aerosol sample conditioning in high-humidity environment. The system was installed at Anmyeon-do Global Atmosphere Watch (GAW) station, where high humidity levels and elevated dew point temperatures are typical, especially during summer. From 2017 to 2018, when heating method was used, it was challenging to maintain the relative humidity (RH) below 40% in the aerosol sample inlet, with the RH frequently exceeding 60% during July and August. After introducing the dry air dilution system in 2019 and 2020, the RH in the instrument remained below 40% for most of the year, including during peak humidity periods. Analysis showed that, compared to heating, the dry air dilution system achieved an average RH reduction rate of 45~72% in high-humidity conditions, while heating achieved only 23~60%. Despite higher initial costs, the dry air dilution system can be a cost-effective solution for long-term aerosol observations, ensuring reliable data quality in coastal and high-humidity environments. Future studies should focus on optimizing the system for diverse climate conditions to broaden its applicability in global atmospheric monitoring networks.