scholarly journals Investigation of factors controlling PM2.5 variability across the South Korean Peninsula during KORUS-AQ

Elem Sci Anth ◽  
2020 ◽  
Vol 8 ◽  
Author(s):  
Carolyn E. Jordan ◽  
James H. Crawford ◽  
Andreas J. Beyersdorf ◽  
Thomas F. Eck ◽  
Hannah S. Halliday ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
South Korea ◽  
Water Uptake ◽  
Vertical Mixing ◽  
Future Research ◽  
Aerosol Composition ◽  
Mixing Depth ◽  
South Korean ◽  
Transboundary Transport

The Korea – United States Air Quality Study (May – June 2016) deployed instrumented aircraft and ground-based measurements to elucidate causes of poor air quality related to high ozone and aerosol concentrations in South Korea. This work synthesizes data pertaining to aerosols (specifically, particulate matter with aerodynamic diameters <2.5 micrometers, PM2.5) and conditions leading to violations of South Korean air quality standards (24-hr mean PM2.5 < 35 µg m–3). PM2.5 variability from AirKorea monitors across South Korea is evaluated. Detailed data from the Seoul vicinity are used to interpret factors that contribute to elevated PM2.5. The interplay between meteorology and surface aerosols, contrasting synoptic-scale behavior vs. local influences, is presented. Transboundary transport from upwind sources, vertical mixing and containment of aerosols, and local production of secondary aerosols are discussed. Two meteorological periods are probed for drivers of elevated PM2.5. Clear, dry conditions, with limited transport (Stagnant period), promoted photochemical production of secondary organic aerosol from locally emitted precursors. Cloudy humid conditions fostered rapid heterogeneous secondary inorganic aerosol production from local and transported emissions (Transport/Haze period), likely driven by a positive feedback mechanism where water uptake by aerosols increased gas-to-particle partitioning that increased water uptake. Further, clouds reduced solar insolation, suppressing mixing, exacerbating PM2.5 accumulation in a shallow boundary layer. The combination of factors contributing to enhanced PM2.5 is challenging to model, complicating quantification of contributions to PM2.5 from local versus upwind precursors and production. We recommend co-locating additional continuous measurements at a few AirKorea sites across South Korea to help resolve this and other outstanding questions: carbon monoxide/carbon dioxide (transboundary transport tracer), boundary layer height (surface PM2.5 mixing depth), and aerosol composition with aerosol liquid water (meteorologically-dependent secondary production). These data would aid future research to refine emissions targets to further improve South Korean PM2.5 air quality.

scholarly journals Fine particle pH and sensitivity to NH<sub>3</sub> and HNO<sub>3</sub> over summertime South Korea during KORUS-AQ

2020 ◽  
Author(s):  
Ifayoyinsola Ibikunle ◽  
Andreas Beyersdorf ◽  
Pedro Campuzano-Jost ◽  
Chelsea Corr ◽  
John D. Crounse ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Deposition Velocity ◽  
Liquid Water Content ◽  
Aerosol Formation ◽  
Aerosol Composition ◽  
New Approach ◽  
South Korean ◽  
Inorganic Nitrate ◽  
Nitrate Availability ◽  
Trace Species

Abstract. Using a new approach that constrains thermodynamic modeling of aerosol composition with measured gas-to-particle partitioning of inorganic nitrate, we estimate the acidity levels for aerosol sampled in the South Korean planetary boundary layer during the NASA/NIER KORUS-AQ field campaign. The pH (mean ± 1σ = 2.43 ± 0.68) and aerosol liquid water content determined were then used to determine the chemical regime of the inorganic fraction of particulate matter (PM) sensitivity to ammonia and nitrate availability. We found that the aerosol formation is always sensitive to HNO3 levels, especially in highly polluted regions, while it is only exclusively sensitive to NH3 in some rural/remote regions. Nitrate levels are further promoted because dry deposition velocity is low and allows its accumulation in the boundary layer. Because of this, HNO3 reductions achieved by NOx controls prove to be the most effective approach for all conditions examined, and that NH3 emissions can only partially affect PM reduction for the specific season and region. Despite the benefits of controlling PM formation to reduce ammonium-nitrate aerosol and PM mass, changes in the acidity domain can significantly affect other processes and sources of aerosol toxicity (such as e.g., solubilization of Fe, Cu and other metals) as well as the deposition patterns of these trace species and reactive nitrate.

A review of turbulence in the very stable nocturnal boundary layer and its implications for air quality

2005 ◽  
Vol 29 (2) ◽  
pp. 171-188 ◽  
Author(s):  
J. A. Salmond ◽  
I. G. McKendry
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Spatial Scales ◽  
Vertical Mixing ◽  
Three Dimensional ◽  
Nocturnal Boundary Layer ◽  
Dimensional Distribution ◽  
Temporal And Spatial ◽  
Fraser Valley ◽  
Spatial And Temporal Characteristics

Turbulence in the very stable nocturnal boundary layer is weak and typically characterized by intermittent bursts of activity. It often exists in isolated layers or pockets generated primarily from localized shear instabilities. As a result, turbulence is rarely in equilibrium with the conditions of the underlying surface. Given the layered structure of the nocturnal boundary layer, the spatial and temporal characteristics of turbulent activity (and resulting vertical mixing) can have a significant affect on local air quality at hourly to diurnal scales. However, while there is a wealth of information concerning turbulent processes operating during daytime conditions, until recently comparatively few studies have focused on the nocturnal case. Nevertheless the three-dimensional distribution of pollutants in the nocturnal boundary layer may have a significant impact on local pollutant budgets at a variety of temporal and spatial scales. This paper reviews recent progress in our understanding of the structure of, and processes operating in, the very stable nocturnal boundary layer. Then, drawing upon case studies from the Lower Fraser Valley, of British Columbia, Canada, it considers the implications of these developments for pollutant transport and surface air quality.

scholarly journals Impacts of atmospheric vertical structures on transboundary aerosol transport from China to South Korea

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hyo-Jung Lee ◽  
Hyun-Young Jo ◽  
Sang-Woo Kim ◽  
Moon-Soo Park ◽  
Cheol-Hee Kim
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
South Korea ◽  
Long Range ◽  
Korean Peninsula ◽  
Ground Level ◽  
The Yellow Sea ◽  
Observation Data ◽  
Haze Pollution ◽  
High Concentrations

Abstract To forecast haze pollution episodes caused by high concentrations of long-range transported pollutants emitted in the areas upstream of South Korea, it is crucial to study and identify their behaviour. We analysed the three-dimensional air quality structure in Seoul using ground observation data and aerosol lidar measurements to identify vertical aerosol intrusion into the Korean Peninsula during the spring of 2016. The intrusions were particularly affected by the development of the atmospheric boundary layer (ABL) in the leeward regions. The nocturnal pollutant intrusion into the Korean peninsula via the Yellow Sea was examined using measured data. The pollutants first reached the area above the nocturnal boundary layer (548 ± 180 m) and approached ground level on the following day due to convective mixing depending on the convective ABL growth (1182 ± 540 m) in daytime. These intrusion mechanisms were mostly attributed to extremely high concentrations (i.e. >100 μg m−3) of fine particulate matter in the leeward regions, accounting for four of the total of six cases for which the warnings and alerts were issued in Seoul Metropolitan Area over a year-long period (2016). The horizontal and vertical pathways of the long-range transported pollutants and the atmospheric vertical structure were identified as key factors affecting the surface air quality concentration in the leeward regions.

scholarly journals Use of Mobile Grocery Shopping Application: Motivation and Decision-Making Process among South Korean Consumers

2021 ◽  
Vol 16 (7) ◽  
pp. 2672-2693
Author(s):  
Hyungjoon Kim
Keyword(s):  
South Korea ◽  
Purchase Intention ◽  
Subjective Norms ◽  
Mobile App ◽  
Purchase Behavior ◽  
Future Research ◽  
Perceived Behavioral Control ◽  
Grocery Shopping ◽  
User Intention ◽  
South Korean

With the revitalization of the online grocery trading market, many consumers are using mobile applications to purchase groceries. Although past studies were conducted on online grocery purchases, few measured mobile app users in a conceptual model that combines both motivational needs and behavioral components. Grounded in the uses and gratifications theory and the theory of planned behavior, this study investigated utilitarian motives, hedonic motives, experiential motives, attitudes, subjective norms, perceived behavioral control, purchase intention, and purchase behavior among mobile grocery app users in South Korea. As an additional analysis, a comparison between users and non-users of mobile grocery apps was implemented. The results showed that the utilitarian motives of grocery app users significantly influenced attitudes, attitudes and subjective norms influenced user intention, and user intention influenced grocery purchase behavior. Users showed statistically higher utilitarian motives, hedonic motives, and attitudes than non-users. The results suggest that South Korean consumers hold positive attitudes toward mobile grocery shopping and that the opinions of others may influence the decision to use the services. Mobile groceries in South Korea may have the potential for continued growth if individuals’ perceived control of the service improves. Implications and suggestions for future research are discussed.

scholarly journals Influence of the Anthropogenic Fugitive, Combustion, and Industrial Dust on Winter Air Quality in East Asia

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 790 ◽  
Author(s):  
Jaein I. Jeong ◽  
Rokjin J. Park
Keyword(s):  
Air Quality ◽  
South Korea ◽  
East Asia ◽  
Atmospheric Transport ◽  
Eastern China ◽  
Emissions Inventory ◽  
Industrial Dust ◽  
Transport Experiment ◽  
Transboundary Transport ◽  
Regional Emissions

We estimate the effects of the anthropogenic fugitive, combustion, and industrial dust (AFCID) on winter air quality in China and South Korea for November 2015–March 2016 using the Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment (KU-CREATE) monthly anthropogenic emission inventory in conjunction with a nested version of GEOS-Chem. Including AFCID emissions in models results in a better agreement with observations and a reduced normalized mean bias of −28% compared to −40% without AFCID. Furthermore, we find that AFCID amounts to winter PM10 concentrations of 17.9 μg m−3 (17%) in eastern China (30−40° N, 112−120° E) with the largest contribution of AFCID to winter PM10 concentrations of up to 45 μg m−3 occurring in eastern China causing a significant impact on air quality to downwind regions. Including AFCID in the model results in an increase of simulated winter PM10 concentrations in South Korea by 3.1 μg m−3 (9%), of which transboundary transport from China accounts for more than 70% of this increased PM10 concentration. Our results indicate that AFCID is an essential factor for winter PM10 concentrations over East Asia and its sources and physical characteristics need to be better quantified to improve PM air quality forecasts.

Career Indecision in China

2016 ◽  
Vol 25 (3) ◽  
pp. 526-536 ◽  
Author(s):  
Meghan K. Roche ◽  
Andrea L. Carr ◽  
In Heok Lee ◽  
Jiaxin (Henry) Wen ◽  
Steven D. Brown
Keyword(s):  
Young Adults ◽  
South Korea ◽  
Measurement Invariance ◽  
Factor Structure ◽  
Five Factor Model ◽  
The United States ◽  
Career Indecision ◽  
Future Research ◽  
Chinese Sample ◽  
South Korean

This study explored the measurement equivalence of the Career Indecision Profile (CIP) in a Chinese sample with both U.S. and South Korean samples. Past measurement invariance research on the CIP in four international samples (Icelandic young adults, Italian adolescents, French-speaking young adults, and South Korean adolescents) has supported a four-factor structure in the U.S. and in the three Western samples but not in the South Korean sample. Rather, a five-factor structure emerged in South Korea. This study sought to identify whether either the four- or five-factor structure would demonstrate suitable fit for a Chinese adolescent sample. Results indicated that the four-factor structure developed in the United States did not replicate in China, but the five-factor structure found in South Korea showed adequate fit. Additional analysis suggested full metric invariance on all five scales and scalar invariance on four of the five scales. These findings extend the past measurement invariance work with the CIP to suggest two potential ways with which to understand career indecision: a four-factor structure in Western cultures and a five-factor model in Eastern cultures. Future research needs are discussed.

A Combined Local and Nonlocal Closure Model for the Atmospheric Boundary Layer. Part II: Application and Evaluation in a Mesoscale Meteorological Model

2007 ◽  
Vol 46 (9) ◽  
pp. 1396-1409 ◽  
Author(s):  
Jonathan E. Pleim
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Atmospheric Boundary Layer ◽  
Mesoscale Model ◽  
Evaluation Studies ◽  
Vertical Mixing ◽  
Model Performance ◽  
State University ◽  
Meteorological Model ◽  
Wind Profilers

Abstract A new combined local and nonlocal closure atmospheric boundary layer model called the Asymmetric Convective Model, version 2, (ACM2) was described and tested in one-dimensional form and was compared with large-eddy simulations and field data in Part I. Herein, the incorporation of the ACM2 into the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) is described. Model simulations using the MM5 with the ACM2 are made for the summer of 2004 and evaluated through comparison with surface meteorological measurements, rawinsonde profile measurements, and observed planetary boundary layer (PBL) heights derived from radar wind profilers. Overall model performance is as good as or better than similar MM5 evaluation studies. The MM5 simulations with the ACM2 compare particularly well to PBL heights derived from radar wind profilers during the afternoon hours. The ACM2 is designed to simulate the vertical mixing of any modeled quantity realistically for both meteorological models and air quality models. The next step, to be described in a subsequent article, is to incorporate the ACM2 into the Community Multiscale Air Quality (CMAQ) model for testing and evaluation.

scholarly journals Coupled Air Quality and Boundary-Layer Meteorology in Western U.S. Basins during Winter: Design and Rationale for a Comprehensive Study

2021 ◽  
pp. 1-94
Author(s):  
A. Gannet Hallar ◽  
Steven S. Brown ◽  
Erik Crosman ◽  
Kelley C. Barsanti ◽  
Christopher D. Cappa ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Atmospheric Chemistry ◽  
Salt Lake ◽  
Control Strategies ◽  
Research Area ◽  
Future Research ◽  
Surface Boundary ◽  
Mixing Processes ◽  
Near Surface

AbstractWintertime episodes of high aerosol concentrations occur frequently in urban and agricultural basins and valleys worldwide. These episodes often arise following development of persistent cold-air pools (PCAPs) that limit mixing and modify chemistry. While field campaigns targeting either basin meteorology or wintertime pollution chemistry have been conducted, coupling between interconnected chemical and meteorological processes remains an insufficiently studied research area. Gaps in understanding the coupled chemical-meteorological interactions that drive high pollution events make identification of the most effective air-basin specific emission control strategies challenging. To address this, a September 2019 workshop occurred with the goal of planning a future research campaign to investigate air quality in Western U.S. basins. Approximately 120 people participated, representing 50 institutions and 5 countries. Workshop participants outlined the rationale and design for a comprehensive wintertime study that would couple atmospheric chemistry and boundary-layer and complex-terrain meteorology within western U.S. basins. Participants concluded the study should focus on two regions with contrasting aerosol chemistry: three populated valleys within Utah (Salt Lake, Utah, and Cache Valleys) and the San Joaquin Valley in California. This paper describes the scientific rationale for a campaign that will acquire chemical and meteorological datasets using airborne platforms with extensive range, coupled to surface-based measurements focusing on sampling within the near-surface boundary layer, and transport and mixing processes within this layer, with high vertical resolution at a number of representative sites. No prior wintertime basin-focused campaign has provided the breadth of observations necessary to characterize the meteorological-chemical linkages outlined here, nor to validate complex processes within coupled atmosphere-chemistry models.

Sign in / Sign up

Export Citation Format

Share Document