https://repository.kopri.re.kr/handle/201206/5214 2026-04-20T19:17:43Z 2026-04-20T19:17:43Z Ahn, Dha Hyun Choi, Taejin Kim, Jhoon Park, Sang Seo Lee, Yun Gon Kim, Seong-Joong Koo, Ja-Ho https://repository.kopri.re.kr/handle/201206/10911 2022-03-24T07:14:17Z 2019-04-01T00:00:00Z

Title: Southern Hemisphere mid- and high-latitudinal AOD, CO, NO2, and HCHO: spatiotemporal patterns revealed by satellite observations Authors: Ahn, Dha Hyun; Choi, Taejin; Kim, Jhoon; Park, Sang Seo; Lee, Yun Gon; Kim, Seong-Joong; Koo, Ja-Ho Abstract: To assess air pollution emitted in Southern Hemisphere mid-latitudes and transported to Antarctica, we investigate the climatological mean and temporal trends in aerosol optical depth (AOD), carbon monoxide (CO), nitrogen dioxide (NO2), and formaldehyde (HCHO) columns using satellite observations. Generally, all these measurements exhibit sharp peaks over and near the three nearby inhabited continents: South America, Africa, and Australia. This pattern indicates the large emission effect of anthropogenic activities and biomass burning processes. High AOD is also found over the Southern Atlantic Ocean, probably because of the sea salt production driven by strong winds. Since the pristine Antarctic atmosphere can be polluted by transport of air pollutants from the mid-latitudes, we analyze the 10-day back trajectories that arrive at Antarctic ground stations in consideration of the spatial distribution of mid-latitudinal AOD, CO, NO2, and HCHO. We find that the influence of mid-latitudinal emission differs across Antarctic regions: western Antarctic regions show relatively more back trajectories from the mid-latitudes, while the eastern Antarctic regions do not show large intrusions of mid-latitudinal air masses. Finally, we estimate the long-term trends in AOD, CO, NO2, and HCHO during the past decade (2005？2016). While CO shows a significant negative trend, the others show overall positive trends. Seasonal and regional differences in trends are also discussed.

2019-04-01T00:00:00Z Kim, Seong-Joong Lim, Chang-Kyu https://repository.kopri.re.kr/handle/201206/10613 2022-03-24T07:14:27Z 2018-12-01T00:00:00Z

Title: A brief review of recent Antarctic climate change Authors: Kim, Seong-Joong; Lim, Chang-Kyu Abstract: In response to the increase in anthropogenic greenhouse gases, the Arctic temperature is increasing rapidly by 2-3 times other regions. This larger Arctic warming than lower latitudes is called 'Arctic Amplification'(Overland et al., 2017; Goose et al., 2018). Associated with the Arctic Amplification, the Arctic sea ice is declining rapidly and Greenland ice sheet is melting rapidly, especially around the coastal margins (State of Climate, 2018). However, Antarctic climate change appears to be different from the Arctic. In the western part of Antarctica, surface temperature is rising rapidly with large sea and land ice melting, but in the eastern part, there is little temperature change with slight increase in sea ice extent. The contrasting east-west temperature response is illustrated by the deepening of the Amundsen Sea Low whose upstream brings warm maritime air to the Antarctic peninsula and Amundsen-Bellingshausen Seas, but downstream air provides cold air to the Ross Sea, increasing sea ice. Besides, the increase in Southern Annular Mode (SAM) phase due to stratospheric ozone reduction enhances westerly winds, pushing sea ice northward by Ekman divergence and cooling east Antarctica. In this study, we review the recent Antarctic climate change and its possible causes.

2018-12-01T00:00:00Z Nagano, Hirohiko Kim, Yongwon Lee, Bang Yong Shigeta, Haruka Inubushi, Kazuyuki https://repository.kopri.re.kr/handle/201206/10855 2022-03-24T07:14:13Z 2018-11-01T00:00:00Z

Title: Laboratory examination of greenhouse gaseous and microbial dynamics during thawing of frozen soil core collected from a black spruce forest in Interior Alaska Authors: Nagano, Hirohiko; Kim, Yongwon; Lee, Bang Yong; Shigeta, Haruka; Inubushi, Kazuyuki Abstract: In this study, we conducted an incubation experiment on a frozen soil core collected from a black spruce forest in Interior Alaska, in order to investigate potential changes in greenhouse gaseous (GHG) and microbial dynamics during thawing of frozen soil. The soil thawing is an important environmental process determining the annual GHG balance in the northern high-latitude ecosystem. A core spanning the ground surface to upper permafrost with a depth of 90 cm was vertically grouped into three layers (top, middle, and bottom layers). Then, 12 soil samples from 3 layers (i.e., 4 soil samples per layer) were incubated for 3 weeks, and net carbon dioxide (CO2) and methane (CH4) release/uptake rates were estimated. During the incubation, temperature was changed weekly from 0 to 5, then 10°C. The net amounts of CO2 released by six of the eight soil samples from the top and middle layers were 1.5？19.2- fold greater at 5°C than at 0°C, while the release at 10°C was reduced in the cases of three of these six soil samples. Net CH4 release was the greatest in bottom-layer soil samples incubated at 0°C. Then, low but apparent CH4 release was observed in top and middle-layer soil samples incubated at 0°C. At 5 and 10°C, net CH4 release from bottom-layer soil samples was decreased. Then, net CH4 uptake was observed in the top and the middle-layer soil samples. Both net uptake and release of CH4 were reduced upon the addition of a chemical inhibitor (i.e., 2-bromoethane sulfonate) of anaerobic methanotrophic and methanogenic activity. The bacterial and archaeal community structures based on 16S rRNA amplicon analysis were changed along the depth, while they were less changed during thawing. Thus, it was found that soil GHG dynamics responded sensitively and variously to thawing, while there was less change in 16S rRNA-based microbial community structures during the thawing progress.

2018-11-01T00:00:00Z Chambers, Scott D. Preunkert, Susanne Weller, Rolf Hong, Sang-Bum Humphries, Ruhi S. Tositti, Laura Angot, Helene Legrand, Michel Williams, Alastair G. Griffiths, Alan D. Crawford, Jagoda Simmons, Jack Choi, Taejin Krummel, Paul B. Molloy, Suzie Loh, Zoe Galbally, Ian Wilson, Stephen Magand, Olivier Sprovieri, Francesca Pirrone, Nicola Dommergue, Aurelien https://repository.kopri.re.kr/handle/201206/10607 2022-03-24T07:14:04Z 2018-11-01T00:00:00Z

Title: Characterizing Atmospheric Transport Pathways to Antarctica and the Remote Southern Ocean Using Radon-222 Authors: Chambers, Scott D.; Preunkert, Susanne; Weller, Rolf; Hong, Sang-Bum; Humphries, Ruhi S.; Tositti, Laura; Angot, Helene; Legrand, Michel; Williams, Alastair G.; Griffiths, Alan D.; Crawford, Jagoda; Simmons, Jack; Choi, Taejin; Krummel, Paul B.; Molloy, Suzie; Loh, Zoe; Galbally, Ian; Wilson, Stephen; Magand, Olivier; Sprovieri, Francesca; Pirrone, Nicola; Dommergue, Aurelien Abstract: We discuss remote terrestrial influences on boundary layer air over the Southern Ocean and Antarctica, and the mechanisms by which they arise, using atmospheric radon observations as a proxy. Our primary motivation was to enhance the scientific community's ability to understand and quantify the potential effects of pollution, nutrient or pollen transport from distant land masses to these remote, sparsely instrumented regions. Seasonal radon characteristics are discussed at 6 stations (Macquarie Island, King Sejong, Neumayer, Dumont d'Urville, Jang Bogo and Dome Concordia) using 1-4 years of continuous observations. Context is provided for differences observed between these sites by Southern Ocean radon transects between 45 and 67 degrees S made by the Research Vessel Investigator. Synoptic transport of continental air within the marine boundary layer (MBL) dominated radon seasonal cycles in the mid-Southern Ocean site (Macquarie Island). MBL synoptic transport, tropospheric injection, and Antarctic outflow all contributed to the seasonal cycle at the sub-Antarctic site (King Sejong). Tropospheric subsidence and injection events delivered terrestrially influenced air to the Southern Ocean MBL in the vicinity of the circumpolar trough (or "Polar Front"). Katabatic outflow events from Antarctica were observed to modify trace gas and aerosol characteristics of the MBL 100-200 km off the coast. Radon seasonal cycles at coastal Antarctic sites were dominated by a combination of local radon sources in summer and subsidence of terrestrially influenced tropospheric air, whereas those on the Antarctic Plateau were primarily controlled by tropospheric subsidence. Separate characterization of long-term marine and katabatic flow air masses at Dumont d'Urville revealed monthly mean differences in summer of up to 5 ppbv in ozone and 0.3 ng m(-3) in gaseous elemental mercury. These differences were largely attributed to chemical processes on the Antarctic Plateau. A comparison of our observations with some Antarctic radon simulations by global climate models over the past two decades indicated that: (i) some models overestimate synoptic transport to Antarctica in the MBL, (ii) the seasonality of the Antarctic ice sheet needs to be better represented in models, (iii) coastal Antarctic radon sources need to be taken into account, and (iv) the underestimation of radon in subsiding tropospheric air needs to be investigated.

2018-11-01T00:00:00Z