The role of a suburban forest in controlling vertical trace gas and OH reactivity distributions – a case study for the Seoul metropolitan area

2021 ◽  
Author(s):  
Saewung Kim ◽  
Roger Seco ◽  
Dasa Gu ◽  
Dianne Sanchez ◽  
Daun Jeong ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Metropolitan Area ◽  
Trace Gases ◽  
Trace Gas ◽  
Photo Oxidation ◽  
Seoul Metropolitan Area ◽  
Vertical Distributions

This study presents vertical distributions of trace gases and OH reactivity in Seoul Metropolitan Area. The comparison between a suburban ground site and an airborne platform illustrates a rapid photo oxidation in the very bottom of the boundary layer.

scholarly journals Locating Battery Swapping Stations for a Smart e-Bus System

2020 ◽  
Vol 12 (3) ◽  
pp. 1142 ◽  
Author(s):  
Joon Moon ◽  
Young Joo Kim ◽  
Taesu Cheong ◽  
Sang Hwa Song
Keyword(s):  
Integer Programming ◽  
Electric Vehicles ◽  
Metropolitan Area ◽  
Public Transportation ◽  
Set Covering ◽  
Programming Models ◽  
Traffic Network ◽  
Seoul Metropolitan Area ◽  
Model Flow

With the growing interest and popularity of electric vehicles (EVs), the electrification of buses has been progressing recently. To achieve the seamless operation of electric buses (e-Buses) for public transportation, some bus stations should play the role of battery swapping station due to the limited travel range of e-Buses. In this study, we consider the problem of locating battery swapping stations for e-Buses on a passenger bus traffic network. For this purpose, we propose three integer programming models (set-covering-based model, flow-based model and path-based model) to model the problem of minimizing the number of stations needed. The models are applied and tested on the current bus routes in the Seoul metropolitan area of South Korea.

scholarly journals Impacts of urban land-surface forcing on ozone air quality in the Seoul metropolitan area

2013 ◽  
Vol 13 (4) ◽  
pp. 2177-2194 ◽  
Author(s):  
Y.-H. Ryu ◽  
J.-J. Baik ◽  
K.-H. Kwak ◽  
S. Kim ◽  
N. Moon
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Urban Area ◽  
Metropolitan Area ◽  
Land Surface ◽  
Urban Boundary Layer ◽  
Breeze Circulation ◽  
Air Masses ◽  
Elevated O3 ◽  
Seoul Metropolitan Area

Abstract. Modified local meteorology owing to heterogeneities in the urban–rural surface can affect urban air quality. In this study, the impacts of urban land-surface forcing on ozone air quality during a high ozone (O3) episode in the Seoul metropolitan area, South Korea, are investigated using a high-resolution chemical transport model (CMAQ). Under fair weather conditions, the temperature excess (urban heat island) significantly modifies boundary layer characteristics/structures and local circulations. The modified boundary layer and local circulations result in an increase in O3 levels in the urban area of 16 ppb in the nighttime and 13 ppb in the daytime. Enhanced turbulence in the deep urban boundary layer dilutes pollutants such as NOx, and this contributes to the elevated O3 levels through the reduced O3 destruction by NO in the NOx-rich environment. The advection of O3 precursors over the mountains near Seoul by the prevailing valley-breeze circulation in the mid- to late morning results in the build-up of O3 over the mountains in conjunction with biogenic volatile organic compound (BVOC) emissions there. As the prevailing local circulation in the afternoon changes to urban-breeze circulation, the O3-rich air masses over the mountains are advected over the urban area. The urban-breeze circulation exerts significant influences on not only the advection of O3 but also the chemical production of O3 under the circumstances in which both anthropogenic and biogenic (natural) emissions play important roles in O3 formation. As the air masses that are characterized by low NOx and high BVOC levels and long OH chain length are advected over the urban area from the surroundings, the ozone production efficiency increases in the urban area. The relatively strong vertical mixing in the urban boundary layer embedded in the sea-breeze inflow layer reduces NOx levels, thus contributing to the elevated O3 levels in the urban area.

scholarly journals The role of snow in controlling halogen chemistry and boundary layer oxidation during Arctic spring: A 1D modelling case study

2021 ◽  
Author(s):  
Shaddy Ahmed ◽  
Jennie L Thomas ◽  
Kathleen Tuite ◽  
Jochen Stutz ◽  
Frank Flocke ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Halogen Chemistry ◽  
1D Modelling
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