2023-2025년 봄철 도심 상공 2차 무기 에어로졸 생성 메커니즘 파악

다국어 초록 (Multilingual Abstract)

Secondary inorganic aerosols （SIA） are major components of PM2.5, and the formation of sulfate and nitrate plays an important role in haze pollution by influencing oxidant levels in gas and aqueous phase reactions as well as the chemical properties of aerosols. Although numerous studies have investigated high PM2.5 episodes during wintertime, which are often driven by ammonium nitrate near the surface, relatively limited attention has been given to springtime high PM2.5 episodes, particularly those occurring near the atmospheric boundary layer. To investigate the formation processes of secondary inorganic species in spring, intensive observation campaigns were conducted from April to June in 2023, 2024, and 2025. Measurements were carried out using a Monitor for AeRosols and Gases in ambient Air （MARGA） installed on the 67th floor of POSCO Tower-Songdo in Incheon, Korea （37.39° N, 126.64° E; approximately 305 m above ground level）. This study site is located on the west coast of the Korean Peninsula, providing an advantageous platform for observing both the horizontal and vertical influences of pollutants transported over long distances from China.
To analyze SIA formation mechanisms according to air mass transport pathways, the cases were classified into conditions characterized by local ventilation or stagnation without long-range transport, and those characterized by local ventilation or stagnation accompanied by long-range transport. Based on hourly concentrations of water-soluble inorganic ions and gaseous precursors measured by MARGA, aerosol liquid water content （ALWC） and aerosol pH were calculated using the thermodynamic equilibrium model ISORROPIA II with relative humidity and temperature as input variables. Using the calculated pH and observed ε（NO3−）, sigmoid-shaped S-curves were constructed. The results showed that pH₅₀ values for most cases were located within the range of 2〈pH〈3.5, indicating that the gas–particle partitioning of nitrate was highly sensitive to ammonia （NH3） concentrations. In addition, the ALWC-pH regime analysis revealed that during high PM2.5 episodes, the nitrate formation system tended to transition from the ‘HNO3-sensitive’ regime to the ‘HNO3 and NH3-sensitive’ regime. This study contributes to a comprehensive understanding of secondary inorganic aerosol formation by interpreting the gas–particle partitioning characteristics of nitrate under summertime conditions while simultaneously considering the ALWC-pH environment and air mass transport pathways.

목차 (Table of Contents)

• 1. 서론 1
• 1.1. 연구배경 1
• 1.2. 연구목적 및 내용 5
• 2. 연구 방법 6
• 2.1. 연구 지점 및 기간 6
• 2.2. 측정장비 9
• 2.3. 열역학적 화학평형 모델 ISORROPIA Ⅱ 18
• 2.4. 기상 및 수송조건에 따른 기단 이동경로 23
• 3. 연구결과 29
• 3.1. 계절별 상층 및 지표 PM2.5 농도 비교 29
• 3.2. 집중관측기간 동안 PM2.5 수용성 무기이온 특성 36
• 3.3. 고농도 사례별 PM2.5 수용성 무기이온 특성 43
• 3.4. 공기궤 이동경로에 따른 고농도 PM2.5 사례일 특성 49
• 3.5. ε(NO3−)-pH S-curve 민감도 분석 56
• 3.6. 입자상 질산염 형성에 대한 NH3와 HNO3의 민감도 분석 59
• 4. 결론 67
• 5. 참고문헌 69
• 6. 부록 99
• 6.1. 서론 99
• 6.2. 방법 101
• 6.2.1. 연구 지점 및 기간 101
• 6.2.2. 측정 방법 103
• 6.2.3. 열역학적 화학평형 모델 ISORROPIA Ⅱ 105
• 6.3. 결과 107
• 6.3.1. ALWC와 pH로 질산염 생성 민감도 분석 107
• 6.4. 결론 109
• 6.5. 참고문헌 111