Analysis of Domestic and Foreign Contributions using DDM in CMAQ during Particulate Matter Episode Period of February 2014 in Seoul

Abstract

This study was carried out to understand the regional contribution of Particulate Matter (PM) emissions from East Asia (82°~149°E, 18°~53°N) to Seoul during high concentration period in February 2014.The Community Multi-scale Air Quality (CMAQ) version 5.0.2 with Decoupled Direct Method (DDM) was used to analyze levels of contributions over Seoul. In order to validate model performance of the CMAQ, predicted PM and its chemical species concentrations were compared to observations in China and Seoul. Model predictions could depict the daily and hourly variations of observed PM. The calculated PM concentrations, however, had a tendency of underestimation. The discrepancies are due to uncertainties of meteorological data, emission inventories and CMAQ model itself.The high PM concentration in Seoul was induced by stationary anticyclone over the West Coast of Korea during 24 to 27 February. The DDM in CMAQ was used to analyze the contributions of emissions from East Asia on Seoul during this PM episode. PM 10 concentration in Seoul is contributed by 39.77%~53.19% from China industrial and urban region, 15.37%~37.10% from South Korea, and 9.03%~18.05% North Korea. These indicate that PM 10 concentrations in Seoul during the episode period are dominated by long-range transport from China region as well as domestic sources. It was also found that the largest contribution region in China were Shandong peninsula during the PM event period.

A Multiscale Tiered Approach to Quantify Contributions: A Case Study of PM2.5 in South Korea During 2010–2017

“…Especially, the 10-m wind speeds were overestimated in the winter by up to 0.8 m/s. We note that the overestimation of the wind speeds was most pronounced in coastal regions ( Figure S4), which is consistent with the findings of Kim et al [32].…”

“…Kim et al [6] reported that the foreign contribution to the annual mean PM 2.5 concentration for SMA comprised over 60% in 2014. The Chinese contribution to the PM 2.5 concentration for SMA in February 2014 was 40-50% during high PM 2.5 days [32] and reached up to 70% at the Bulgwang supersite in Seoul [32]. The range in the Chinese contribution estimated in this study is similar to the results of the previous studies mentioned earlier [5,6,30].…”

Regional contributions to particulate matter concentration in the Seoul metropolitan area, South Korea: seasonal variation and sensitivity to meteorology and emissions inventory

“…Using CMAQ simulation of January 2007, Koo et al (2008) demonstrated that PM 10 transport from China to South Korea is significant, contributing up to 80 % of total concentration during the studied period. Using the CMAQ Decoupled Direct Method (DDM), Kim et al (2016b) also concluded that PM 10 concentration in Seoul is mostly contributed from Chinese industrial and urban regions (39.8-53.2 %), emissions in South Korea (15.4-37.1 %), and emissions in North Korea (9.0-18.1 %). All these studies, however, have examined short, episodic periods, and/or have used a limited set of modeling configurations.…”

Relationship between the actual fine dust concentration and media exposure that influenced the changes in outdoor activity behavior in South Korea

“…Analysis of the contributions of fine dust domestically and from foreign countries in 2018 by NIER revealed that the average foreign contribution constituted about 44–55%, which is different from the 60–80% of high concentration of fine dust known to be contributed by foreign influences 6 . It is supported by the facts that much of fine dust generation is due to domestic factors that are a continuation of domestic high pressure impact and stagnation of Barometer 7 , increased direct air pollutant emissions domestically 8 , 9 , and difference between measurement sites due to emitted air pollutants cannot move away 10 even if high concentration fine dust in the windward area such as Chinese Bohai region formed the inflow route to the South Korea (domestic) by the northwest wind 11 , 12 , 13 .…”