https://repository.kopri.re.kr/handle/201206/14789 2026-04-08T12:22:08Z https://repository.kopri.re.kr/handle/201206/16521 Title: Role of a key microphysical factor in mixed-phase stratocumulus clouds and their interactions with aerosols Authors: Seoung Soo Lee; Chang Hoon Jung; Jinho Choi; Yoon, Young Jun; Junshik Um; Youtong Zheng; Jianping Guo; Manguttathil G. Manoj; Sang-Keun Song Abstract: This study examines the ratio of ice crystal number concentration (ICNC) to cloud droplet num ber concentration (CDNC), that is ICNC CDNC, in mixed-phase stratocumulus clouds. This examination is performed using a large-eddy simulation (LES) framework and is one of the efforts toward a more general un derstanding of mechanisms controlling cloud development and aerosol？cloud interactions, as well as the impacts of ice processes on them in mixed-phase stratocumulus clouds. For the examination, this study compares a case of polar mixed-phase stratocumulus clouds to one of midlatitude mixed-phase stratocumulus clouds with weak precipitation. It is found that ICNC CDNC plays a critical role in causing differences in cloud development with respect to the relative proportion of liquid and ice mass between the cases by affecting in-cloud latent-heat processes. Note that this proportion has an important implication for cloud radiative properties and, thus, for cli mate. It is also found that ICNC CDNC plays a critical role in causing differences in the interactions between clouds and aerosols and in the impacts of ice processes on clouds and their interactions with aerosols between the cases by affecting in-cloud latent-heat processes. Findings of this study suggest that ICNC CDNC can be a simplified general factor that contributes to a more general understanding and parameterization of mixed-phase clouds, their interactions with aerosols and the roles of ice processes within them. 2025-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/14859 Title: Ocean-atmosphere interactions: Different organic components across Pacific and Southern Oceans Authors: 장지이; Park, Jiyeon; Park Jongkwan; Yoon, Young Jun; Dall'Osto Manuel; Park, Ki-Tae; Jang, Eunho; Lee Ji Yi; Cho Kyung Hwa; Lee, Bang Yong Abstract: Sea spray aerosol (SSA) particles strongly influence clouds and climate but the potential impact of ocean microbiota on SSA fluxes is still a matter of active research. Here-by means of in situ ship-borne measurements-we explore simultaneously molecular-level chemical properties of organic matter (OM) in oceans, sea ice, and the ambient PM2.5 aerosols along a tran-sect of 15,000 km from the western Pacific Ocean (36 degrees 13 ' N) to the Southern Ocean (75 degrees 15 ' S). By means of orbitrap mass spectrometry and optical characteristics, lignin-like material (24 +/- 5 %) and humic material (57 +/- 8 %) were found to dominate the pelagic Pacific Ocean surface, while intermediate conditions were observed in the Pacific-Southern Ocean waters. In the marine atmosphere, we found a gradient of features in the aerosol: lignin-like material (31 +/- 9 %) dominat-ing coastal areas and the pelagic Pacific Ocean, whereas lipid-like (23 +/- 16 %) and protein-like (11 +/- 10 %) OM controlled the sympagic Southern Ocean (sea ice-influence). The results of this study showed that the OM composition in the ocean, which changes with latitude, affects the OM in aerosol compositions in the atmosphere. This study highlights the impor-tance of the global-scale OM monitoring of the close interaction between the ocean, sea ice, and the atmosphere. Sympagic primary marine aerosols in polar regions must be treated differently from other pelagic-type oceans. 2023-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/14868 Title: Observational evidence linking ocean sulfur compounds to atmospheric dimethyl sulfide during Icelandic Sea phytoplankton blooms Authors: Lee Kitack; Kim Jun-Seok; Park, Ki-Tae; Park Min-Ji; Jang, Eunho; Gudmundsson Kristinn; Olafsdottir Solveig R.; Olafsson Jon; Yoon, Young Jun; Lee, Bang Yong; Kwon Sae Yun; Kam Jonghun Abstract: In two Icelandic Sea spring blooms (May 2018 and 2019) in the North Atlantic Ocean (62.9-68.0 degrees N, 9.0-28.0 degrees W), chlorophyll -a and dimethylsulfoniopropionate (DMSP) concentrations and DMSP lyase activity (the DMSP-to-dimethyl sul-fide (DMS) conversion efficiency) were measured at 67 stations, and the hourly atmospheric DMS mixing ratios were con-currently measured only in May 2019 at Storhofdi on Heimaey Island, located south of Iceland (63.4 degrees N, 20.3 degrees W). The ocean parameters for biology (i.e., chlorophyll -a, DMSP, and DMSP lyase activity) were broadly associated in distribution; however, the statistical significance of the association differed among four ocean domains and also between 2018 and 2019. Specifically, the widespread dominance of Phaeocystis, coccolithophores, and dinoflagellates (all rich in DMSP and high in DMSP lyase activity) across the study area is a compelling indication that variations in DMSP-rich phytoplankton were likely a main cause of the variations in statistical significance. For all the ocean domains defined here, we found that the DMS production capacity (calculated using the exposures of air masses to ocean biology prior to their arrivals at Heimaey and the atmospheric DMS mixing ratios of those air masses at Heimaey) was surprisingly consistent with in situ ocean S data (i.e., DMSP and DMSP lyase activity). Our study shows that the proposed computational approach en-abled the detection of changes in DMS production and emission in association with changes in ocean primary producers. 2023-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/14874 Title: Parameterization of polydisperse aerosol optical properties during hygroscopic growth Authors: Jung Chang H.; Han Kyung Man; Yoon, Young Jun; Kim Dongchul; Lee Ji Yi; Lee Hyung-Min; Um Junshik; Lee Seoung Soo; Kim Yong Pyo Abstract: Aerosol water uptake and the related influence on its optical properties owing to the hygroscopic growth of polydisperse aerosols have a significant effect on air quality and climate. This study develops an analytical parameterization for a single hygroscopic optical parameter and the scattering enhancement factor for polydisperse aerosol sizes. Polydisperse lognormal size distributions for geometric mean diameters of 0.05-1 mu m and geometric standard deviations of 1.3-2.5 are considered with real refractive indices between 1.35 and 1.6. The analytical expression obtained for the optical parameter is compared to Mie theory and reasonable agreements within the size range investigated in this study are observed. Further, our results show that the analytical expression could express polydispersed aerosol optical properties as a function of geometric mean diameter and geometric standard deviation of a lognormal distribution and the refractive index. The obtained analytical expression can be efficiently used for 3D models with a reduced computational burden. 2023-01-01T00:00:00Z