Atmospheric sulfate formation in the Seoul Metropolitan Area during spring/summer: Effect of trace metal ions.

Despite the effort to control SO emission, sulfate is still one of the major inorganic components of PM in urban area. Moreover, there is still a lack of understanding of the sulfate formation mechanism via SO oxidation under various ambient conditions. In this study, we focus on sulfate formation during a haze pollution episode in the spring/summertime of 2016 in Seoul Metropolitan Area (SMA).

Airborne estimation of SO emissions rates from a coal-fired power plant using two top-down methods: A mass balance model and Gaussian footprint approach.

In this study, two top-down methods-mass balance and Gaussian footprint-were used to determine SO emissions rates via three airborne sampling studies over Korea's largest coal power plant in October 2019 and 2020. During the first two flights in October 2019, mass balance approaches significantly underestimated the SO emissions rates by 75 % and 28 %, respectively, as obtained from the real-time stack monitoring system. Notably, this large discrepancy accounted for the insufficient number of transects altitudes and high levels of background SO along the upwind side.

The Korea-United States Air Quality (KORUS-AQ) field study.

The Korea-United States Air Quality (KORUS-AQ) field study was conducted during May-June 2016. The effort was jointly sponsored by the National Institute of Environmental Research of South Korea and the National Aeronautics and Space Administration of the United States. KORUS-AQ offered an unprecedented, multi-perspective view of air quality conditions in South Korea by employing observations from three aircraft, an extensive ground-based network, and three ships along with an array of air quality forecast models.

OH reactivity in urban and suburban regions in Seoul, South Korea - an East Asian megacity in a rapid transition.

South Korea has recently achieved developed country status with the second largest megacity in the world, the Seoul Metropolitan Area (SMA). This study provides insights into future changes in air quality for rapidly emerging megacities in the East Asian region. We present total OH reactivity observations in the SMA conducted at an urban Seoul site (May-June, 2015) and a suburban forest site (Sep, 2015).

Congener profiles and source-wise phase partitioning analysis of PCDDs/Fs and PCBs in Gyeonggi-do ambient air, South Korea.

The atmospheric concentrations and gas-particle partitioning of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) and polychlorinated biphenyls (PCBs) were investigated at two sites (Suwon and Ansan) in Gyeonggi-do, a heavily industrialized area of Korea, during the year 2010. The sum level (Σ17) of PCDDs/Fs and dioxin-like PCBs (dl-PCBs) in the ambient air at Suwon and Ansan ranged from 0.04 to 0.

Field-measured uptake rates of PCDDs/Fs and dl-PCBs using PUF-disk passive air samplers in Gyeonggi-do, South Korea.

The collection of 2,3,7,8-substituted polychlorinated dibenzo-ρ-dioxins and dibenzo furans (PCDDs/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) using a polyurethane form (PUF)-disk passive air sampler (PAS) was investigated in urban-residential and industrial areas. This was performed to assess the feasibility of using this method as an alternative to an active air sampler (AAS). The PUF-disk PAS was exposed to ambient air over a period of 37-370 and 57-173 days in urban and industrial areas, respectively, together with AASs.

Source identification and apportionment of halogenated compounds observed at a remote site in East Asia.

The sources of halogenated compounds in East Asia associated with stratospheric ozone depletion and climate change are relatively poorly understood. High-precision in situ measurements of 18 halogenated compounds and carbonyl sulfide (COS) made at Gosan, Jeju Island, Korea, from November 2007 to December 2011 were analyzed by a positive matrix factorization (PMF). Seven major industrial sources were identified from the enhanced concentrations of halogenated compounds observed at Gosan and corresponding concentration-based source contributions were also suggested: primary aluminum production explaining 37% of total concentration enhancements, solvent usage of which source apportionment is 25%, fugitive emissions from HCFC/HFC production with 11%, refrigerant replacements (9%), semiconductor/electronics industry (9%), foam blowing agents (6%), and fumigation (3%).

Development of a pretreatment system for the analysis of atmospheric reduced sulfur compounds.

A new pretreatment system was used to evaluate a technology to analyze reduced sulfur compounds (RSCs). To conduct this research, a self-developed custom dryer (Desolvator) and a thermal desorber system (TDS) were installed in the front of GC/PFPD. The syringe pump inside the TDS was devised in such a way that it can be desorbed in a relatively low desorption temperature and low vacuum (730 Pa).

Vertical variability of seawater DMS in the South Pacific Ocean and its implication for atmospheric and surface seawater DMS.

Shipboard measurements of atmospheric dimethylsulfide (DMS) and sea surface water DMS were performed aboard the R/V Onnuri across the South Pacific from Santiago, Chile to Fiji in February 2000. Hydrographic profiles of DMS, dissolved dimethylsulfoniopropionate (DMSP(d)), and particulate DMSP(p) in the upper 200m were obtained at 16 stations along the track. Atmospheric and sea surface water DMS concentrations ranged from 3 to 442pptv and from 0.

Characteristic behavior of peroxyacetyl nitrate (PAN) in Seoul megacity, Korea.

We measured the concentrations of peroxyacetyl nitrate (PAN) and other photochemically reactive species, including O3, NO2, and non-methane hydrocarbons (NMHCs), in the Seoul Metropolitan area (SMA) during May through June in 2004 and 2005. PAN was determined using a fast chromatograph with luminol-based chemiluminescence detection. Mixing ratios of PAN ranged from below the detection limit (0.

Characteristics of atmospheric hydrogen peroxide variations in Seoul megacity during 2002-2004.

Atmospheric hydrogen peroxides (H(2)O(2)) and methyl hydroperoxide (CH(3)OOH) were measured in Seoul, the capital of South Korea. Experiments were performed for several days almost every month from January 2002 to April 2004. Gaseous hydroperoxide was collected in aqueous solution and determined by HPLC-fluorescence method.

Atmospheric peroxides over the North Pacific during IOC 2002 shipboard experiment.

Atmospheric hydrogen peroxide and methyl hydroperoxide were determined onboard the Melville over the North Pacific from Osaka to Honolulu during May-June 2002. The concentrations of H(2)O(2) and CH(3)OOH increased from 0.64+/-0.

DMS photochemistry during the Asian dust-storm period in the Spring of 2001: model simulations vs. field observations.

This study examines the local/regional DMS oxidation chemistry on Jeju Island (33.17 degrees N, 126.10 degrees E) during the Asian dust-storm (ADS) period of April 2001.

Assessment of the photochemistry of OH and NO3 on Jeju Island during the Asian-dust-storm period in the spring of 2001.

In this study, we examined the influence of the long-range transport of dust particles and air pollutants on the photochemistry of OH and NO3 on Jeju Island, Korea (33.17 degrees N, 126.10 degrees E) during the Asian-dust-storm (ADS) period of April 2001.

Monitoring of reduced sulfur compounds in the atmosphere of Gosan, Jeju Island during the Spring of 2001.

The atmospheric concentrations of dimethylsulfide (DMS) and carbon disulfide (CS2) were measured concurrently with relevant environmental parameters at Gosan, Jeju Island, Korea during 5-26 April 2001. The mean concentrations for these two compounds were 18.7+/-17.

Observations of aerosol-bound ionic compositions at Cheju Island, Korea.

To investigate the regional cycle of aerosols and their ionic constituents, three field intensive campaigns were conducted during fall and winter of 1997 and spring of 1998. The concentrations of most ionic species were found to decrease significantly across fall, winter, and spring such that the sum for all cation (and anion) species of each season is computed as: 193 > 96 > 73.7 nequiv m(-3) (and 240 > 104 > 51.