https://repository.kopri.re.kr/handle/201206/11916 2026-04-05T18:43:01Z 2026-04-05T18:43:01Z Sun, Yijie Mao, Rui Gong, Dao-Yi Li, Ying Kim, Seong-Joong Zhang, Xiao-Xiao Zhang, Xuezhen Hamidi, Mehdi https://repository.kopri.re.kr/handle/201206/13321 2022-04-18T01:13:18Z 2022-03-30T00:00:00Z

Title: Decadal shift of the influence of Arctic Oscillation on dust weather frequency in spring over the Middle East during 197-2019 Authors: Sun, Yijie; Mao, Rui; Gong, Dao-Yi; Li, Ying; Kim, Seong-Joong; Zhang, Xiao-Xiao; Zhang, Xuezhen; Hamidi, Mehdi Abstract: Dust weather has an impact on human health and climate change in the Middle East. In this study, we examined the influence of the Arctic Oscillation (AO) on spring dust weather frequency over the Middle East at an interannual timescale during 1974-2019. The results show that there was an interdecadal shift of the influence of AO on dust weather frequency in the Middle East, with a correlation coefficient between the AO index and dust weather frequency changing from -0.52 during 1974-1994 period (P1) to 0.49 during 1995-2013 period (P2). During P1, negative correlations between AO index and dust weather frequency were found over the northern Arabian Peninsula, and during P2, positive ones were mostly over the central and southwestern Arabian Peninsula. In the lower and middle troposphere, negative geopotential height anomalies are associated with the negative phase of the AO over South Europe during P1, whereas negative geopotential height anomalies are associated with the positive phase of the AO over Northeast Africa during P2. The negative height anomalies resulted in the occurrence of more low-pressure systems and, thus, dust weather in the Middle East. It is found that the interdecadal shift of the influence of the AO on dust weather was related to an AO-related northward displacement of wave train propagation during P2. Specifically, during P1 period, the northern branch of AO-related wave train dominated over the middle latitudes of the North Atlantic across South Europe to the Arabian Peninsula, which resulted in the negative height anomaly over South Europe in the lower and middle troposphere. However, during P2 period, the AO-related wave train propagation moved northward, and then, the southern branch of the AO-related wave train dominated over the low latitudes of the North Atlantic across northern Africa to the Arabian Peninsula, which played an important role in the formation of the negative height anomalies over Northeast Africa.

2022-03-30T00:00:00Z Jang, Eunho Park, Ki-Tae Yoon, Young Jun Kim, Kitae Gim, Yeontae Chung, Hyun Young Lee, Kitack Choi, Jinhee Park, Jiyeon Park, Sang-Jong Koo, Ja-Ho Fernandez, Rafael P. Saiz-Lopez, Alfonso https://repository.kopri.re.kr/handle/201206/13629 2022-07-08T00:33:33Z 2022-01-10T00:00:00Z

Title: First-year sea ice leads to an increase in dimethyl sulfide-induced particle formation in the Antarctic Peninsula Authors: Jang, Eunho; Park, Ki-Tae; Yoon, Young Jun; Kim, Kitae; Gim, Yeontae; Chung, Hyun Young; Lee, Kitack; Choi, Jinhee; Park, Jiyeon; Park, Sang-Jong; Koo, Ja-Ho; Fernandez, Rafael P.; Saiz-Lopez, Alfonso Abstract: Dimethyl sulfide (DMS) produced by marine algae represents the largest natural emission of sulfur to the atmosphere. The oxidation of DMS is a key process affecting new particle formation that contributes to the radiative forcing of the Earth. In this study, atmospheric DMS and its major oxidation products (methanesulfonic acid, MSA; non-sea-salt sulfate, nss-SO42-) and particle size distributions were measured at King Sejong station located in the Antarctic Peninsula during the austral spring-summer period in 2018-2020. The observatory was surrounded by open ocean and first-year and multi-year sea ice. Importantly, oceanic emissions and atmospheric oxidation of DMS showed distinct differences depending on source regions. A high mixing ratio of atmospheric DMS was observed when air masses were influenced by the open ocean and first-year sea ice due to the abundance of DMS producers such as pelagic phaeocystis and ice algae. However, the concentrations of MSA and nss-SO42- were distinctively increased for air masses originating from first-year sea ice as compared to those originating from the open ocean and multi-year sea ice, suggesting additional influences from the source regions of atmospheric oxidants. Heterogeneous chemical processes that actively occur over first-year sea ice tend to accelerate the release of bromine monoxide (BrO), which is the most efficient DMS oxidant in Antarctica. Model estimates for surface BrO confirmed that high BrO mixing ratios were closely associated with first-year sea ice, thus enhancing DMS oxidation. Consequently, the concentration of newly formed particles originated from first-year sea ice, which was a strong source area for both DMS and BrO was greater than from open ocean (high DMS but low BrO). These results indicate that first-year sea ice plays an important yet overlooked role in DMS-induced new particle formation in polar environments, where warming-induced sea ice changes are pronounced. (C) 2021 The Authors. Published by Elsevier B.V.

2022-01-10T00:00:00Z Jun, Sang-Yoon Kim, Seong-Joong https://repository.kopri.re.kr/handle/201206/13652 2022-07-08T04:59:38Z 2021-12-01T00:00:00Z

Title: Introduction of PMIP4 Experimental Design for Simulating Quaternary Climates Authors: Jun, Sang-Yoon; Kim, Seong-Joong Abstract: In the Paleoclimate Modeling Intercomparison Project phase 4 (PMIP4), various experiments for quaternary climatic change are being carried out along with the Coupled Model Intercomparison Project phase 6 (CMIP6). With the CMIP6 preindustrial climate experiment (piControl), the equilibrium climate simulations of 6 ka Holocene experiment (midHolocene), 21 ka Last Glacial Maximum experiment (lgm), and 127 ka Last Interglacial experiment (lig127k) experiment, and transient climate simulations of 850-1849 Common Era Last Millennium experiment (past1000), 21-9 ka last deglaciation, and 140-127 ka penultimate deglaciation experiment have been carried out under PMIP4 protocols by several modeling groups. In this technical note, important physical parameters and boundary conditions of these Tier 1 experiments and a list of additional Tier 2 and 3 experiments are summarized.

2021-12-01T00:00:00Z Kwon, Hataek Kim, Seong-Joong Kim, Sang-Woo Kim, Sinu https://repository.kopri.re.kr/handle/201206/13324 2022-04-18T01:45:06Z 2021-12-01T00:00:00Z

Title: Topographical effect of the Antarctic Peninsula on a strong wind event Authors: Kwon, Hataek; Kim, Seong-Joong; Kim, Sang-Woo; Kim, Sinu Abstract: The topographical effect on a strong wind event that occurred on 7 January 2013 at King Sejong Station (KSJ), Antarctica, was investigated using the Polar Weather Research and Forecasting (WRF) model. Numerical experiments applying three different terrain heights of the Antarctic Peninsula (AP) were performed to quantitatively estimate the topographical effect on the selected strong wind event. The experiment employing original AP topography successfully represented the observed features in the strong wind event, both in terms of peak wind speed (by similar to 94%; similar to 19.7 m/s) and abrupt transitions of wind speed. In contrast, the experiment with a flattened terrain height significantly underestimated the peak wind speeds (by similar to 51%; similar to 10.4 m/s) of the observations. An absence of AP topography failed to simulate both a strong discontinuity of sea-level pressure fields around the east coast of the AP and a strong south-easterly wind over the AP. As a result, the observed downslope windstorm, driven by a flow overriding a barrier, was not formed at the western side of the AP, resulting in no further enhancement of the wind at KSJ. This result demonstrates that the topography of the AP played a critical role in driving the strong wind event at KSJ on 7 January 2013, accounting for similar to 50% of the total wind speed.

2021-12-01T00:00:00Z