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This study estimated greenhouse gas (GHG) and air pollutant emissions from aircraft in the troposphere (aircraft cruise altitudes, 1 - 12 km) over South Korea over a two-year period (2009 - 2010) using an activity-based (Landing and Take-Off (LTO) cycle) methodology. Both domestic and international LTOs covering 4 major airports and 11 smaller airports in South Korea were considered. The annual mean GHG emissions (CO2, N2O, CH4, and H2O) in the troposphere (1 - 12 km) over South Korea during the study period were approximately 3.5 x 10³, 3.4 x 10-2, -6.6 x 10-2, and 1.4 x 10³ kiloton (kt) yr-1, respectively. The tropospheric air pollutant emissions (CO, NOx, VOCs, and PM2.5) were approximately 3.0, 20, 1.0, and 0.2 kt yr-1, respectively. The monthly GHG and air pollutant emissions showed no significant variations. The GHG and air pollutant emissions during cruises over the South Korean airspace were significant contributors to (e.g., about 80% for NOx and about 75% for CO2) the total national aviation emissions including the emissions at airports, boundary layer and the free troposphere. [ABSTRACT FROM AUTHOR]

The impact of land cover change in the intertidal zone (8.2% of the total surface area) on meteorology was evaluated using the Weather Research and Forecasting (WRF) model during summer (19 - 21 August 2016) and winter (9 - 11 February 2016). The heat flux change in the intertidal zone due to the tidal effects was greater in summer than in winter. During high tide in summer, the heat flux increased before sunrise and after sunset and decreased after sunrise and before sunset. During low tide, the overall heat flux decreased. In winter, a notable feature was the positive sensible heat flux before sunrise and after sunset during high tide due to a high sea surface temperature. The horizontal and vertical impacts of the tidal phenomena on the coastal meteorology were more pronounced during high tide than during low tide. The temperature decreased in inland areas and intertidal zone in summer afternoons, and increased at sea in winter mornings. The water vapor mixing ratio during the summer period increased in inland from the coastline. The wind speed during high tide at sea increased overall in summer and winter due to the decreased roughness length. During the summer period, the westerly wind speed significantly increased in the lower atmosphere (within 0.4 km) over coastal areas, and the easterly wind speed increased at the heights (approximately 1 km) of the return current of the sea breeze. These horizontal and vertical variations in sea breeze circulation induced horizontal meteorological differences in the Seoul metropolitan areas (approximately 30 km away from the coastline) and vertical differences within the planetary boundary layer (approximately 1.5 km altitude). [ABSTRACT FROM AUTHOR]