Spatiotemporal variations of air pollutants (O<sub>3</sub>, NO<sub>2</sub>, SO<sub>2</sub>, CO, PM<sub>10</sub>, and VOCs) with land-use types

Abstract

Abstract. The spatiotemporal variations of surface air pollutants (O 3 , NO 2 , SO 2 , CO, and PM 10 ) with four land-use types, residence (R), commerce (C), industry (I) and greenbelt (G), have been investigated at 283 stations in South Korea during 2002-2013, using routinely observed data. The volatile organic compound (VOC) data at nine photochemical pollutant monitoring stations available since 2007 were utilized in order to examine their effect on the ozone chemistry. The land-use types, set by the Korean government, were generally consistent with the satellite-derived land covers and with the previous result showing anti-correlation between O 3 and NO 2 in diverse urban areas. The relationship between the two pollutants in the Seoul Metropolitan Area (SMA) residence land-use areas was substantially different from that outside of the SMA, probably due to the local differences in vehicle emissions. The highest concentrations of air pollutants in the diurnal, weekly, and annual cycles were found in industry for SO 2 and PM 10 , in commerce for NO 2 and CO, and in greenbelt for O 3 . The concentrations of air pollutants, except for O 3 , were generally higher in big cities during weekdays, while O 3 showed its peak in suburban areas or small cities during weekends. The weekly cycle and trends of O 3 were significantly out of phase with those of NO 2 , particularly in the residential and commercial areas, suggesting that vehicle emission was a major source in those areas. The ratios of VOCs to NO 2 for each of the land-use types were in the order of I (10.2) > C (8.7) > G (3.9) > R (3.6), suggesting that most areas in South Korea were likely to be VOC-limited for ozone chemistry. The pollutants (NO 2 , SO 2 , CO, and PM 10 ) except for O 3 have decreased, most likely due to the effective government control. The total oxidant values (OX = O 3 + NO 2 ) with the land-use types were analyzed for the local and regional (or background) contributions of O 3 , respectively, and the order of OX (ppb) was C (57.4) > R (53.6) > I (50.7) > G (45.4), indicating the greenbelt observation was close to the background.

Regional Differences of Primary Meteorological Factors Impacting O3 Variability in South Korea

“…Korea is generally known as a VOC-limited (sensitive) area [20]. In such an environment, the O 3 concentration is generally proportional to VOCs and inversely proportional to NOx.…”

“…It is known that the production and disappearance of O 3 is balanced through the reaction of O 3 -NO-NO 2 photo stationary state, but the oxidation of VOC causes NO 2 production by alkyl-radical (RO 2 ) and hydroxy-radical (HO 2 ) to accumulate O 3 [19]. According to previous studies, Korea, with many industrial emission sources, is generally known as a VOC-limited area [20]. Thus, the O 3 concentration is mainly determined by the increase in VOC emissions or the decrease in NOx emissions [10,11].…”

“…In particular, Camalier et al [21] and Otero et al [23] analyzed the regional major meteorological factors for O 3 concentration using a statistics regression model. Other studies have also been conducted to examine the effects of certain meteorological factors, such as regional wind pattern [19,20]. In Korea, however, studies on the impacts of meteorological factors on the air quality in different regions are not sufficient and there have only been a few case studies on areas with concentrated emission sources [25,26].…”

Diurnal variation of aerosol optical depth and PM<sub>2.5</sub> in South Korea: a synthesis from AERONET, satellite (GOCI), KORUS-AQ observation, and the WRF-Chem model

“…An early study by Wang and Christopher (2003) relied on a linear relationship to investigate the Moderate Resolution Imaging Spectroradiometer (MODIS) AOD and 24 h average and monthly average PM 2.5 concentrations. Other efforts have combined the use of satellite AOD with local scaling factors from global chemistry transport models; columnar NO 2 ; and factors such as the planetary boundary height, the temperature inversion layer, relative humidity, season, and site location (Liu et al, 2004(Liu et al, , 2005Ma et al, 2016;van Donkelaar et al, 2010;Zang et al, 2017;Zheng et al, 2016;Qu et al, 2016). A review by Hoff and Christopher (2009) summarizes that "the satellite precision in measuring AOD is ±20 % and the prediction of PM 2.5 concentrations from these values is ±30 % in the most careful studies.…”

Novel Technology for the Removal of Brilliant Green from Water: Influence of Post-Oxidation, Environmental Conditions, and Capping

“…Ozone and NOx (NO and NO 2 ) are produced from natural and anthropogenic sources and are present in the environment in a significant quantity. 44 O 3 is a greenhouse gas (mainly formed via photochemical oxidation of carbon monoxide and volatile organic compounds). 45…”