https://repository.kopri.re.kr/handle/201206/13385 2026-04-25T21:42:04Z 2026-04-25T21:42:04Z Lee, Bang Yong https://repository.kopri.re.kr/handle/201206/14763 2023-12-04T02:29:33Z 2023-11-28T00:00:00Z

Title: Interrelationship Investigation and Comprehensive Monitoring based on Permafrost-Atmospheric Environment Authors: Lee, Bang Yong

2023-11-28T00:00:00Z 박근보 김기주 Kim, KwanSoo 홍원택 https://repository.kopri.re.kr/handle/201206/14421 2023-05-08T16:37:13Z 2023-01-01T00:00:00Z

Title: Characterization of Active Layer at Different Degrees of Patterned Ground Development using Electrical Resistivity Tomography Survey Authors: 박근보; 김기주; Kim, KwanSoo; 홍원택 Abstract: Active layer thickness in extremely cold regions is an indicator of global climate change, but it is also affected by the terrain types. Among the different terrain types typical to cold regions, patterned ground is of interest because it develops over time. Thus, investigating the active layer at different degrees of patterned ground development is required to understand the variability in its distribution. In this study, an electrical resistivity tomography (ERT) survey is conducted at three study sites to investigate the distribution of the active layer according to the degree of patterned ground development. The results of the ERT surveys show that the active layer is thinner, and the patterned ground develops better on an active layer with a small slope and stagnant porewater. Thawing of permafrost may be accelerated around patterned ground. As the ERT survey investigates geological structures without disturbing the target ground, it may be an effective method to monitor geological structures in extremely cold regions and interactions of the active layer with the surrounding conditions.

2023-01-01T00:00:00Z Chang H. Jung Hyung-Min Lee Dasom Park Yoon, Young Jun Y. Choi Junshik Um S.S.Lee Ji Yi Lee Yong Pyo Kim https://repository.kopri.re.kr/handle/201206/14641 2023-09-25T16:37:17Z 2023-01-01T00:00:00Z

Title: Parameterization of below-cloud scavenging for polydisperse fine mode aerosols as a function of rain intensity Authors: Chang H. Jung; Hyung-Min Lee; Dasom Park; Yoon, Young Jun; Y. Choi; Junshik Um; S.S.Lee; Ji Yi Lee; Yong Pyo Kim Abstract: The below-cloud aerosol scavenging process by precipitation is one of the most important mechanisms to remove aerosols from the atmosphere. Due to its complexity and dependence on both aerosol and raindrop sizes, wet scavenging process has been poorly treated, especially during the removal of fine particles. This makes the numerical simulation of below-cloud scavenging in large-scale aerosol models unrealistic.To consider the slip effects of submicron particles, a simplified expression for the diffusion scavenging was developed by approximating the Cunningham slip correction factor. The derived analytic solution was parameterized as a simple power function of rain intensity under the assumption of the lognormal size distribution of particles. The resultant approximated expression was compared to the observed data and the results of previous studies including a 3D atmospheric chemical transport model simulation. Compared with the default GEOS-Chem coefficient of 0.00106R0.61 and the observation-based coefficient of 0.0144R0.9268, the coefficient of a and b in m = aRb spread in the range of 0.0002- 0.1959 for a and 0.3261- 0.525 for b over a size distribution of GSD of 1.3-2.5 and a geometric mean diameter of 0.01- 2.5 μm. Overall, this study showed that the scavenging coefficient varies widely by orders of magnitude according to the size distribution of particles and rain intensity. This study also demonstrated that the obtained simplified expression could consider the theoretical approach of aerosol polydispersity. Our proposed analytic approach showed that results can be effectively applied for reduced computational burden in atmospheric modeling.

2023-01-01T00:00:00Z Kim, Dockyu 채남이 Kim, Mincheol Nam, Sungjin Kim, Tai Kyoung Park, Ki-Tae Lee, Bang Yong 김응빈 Lee, Hyoungseok https://repository.kopri.re.kr/handle/201206/14128 2022-11-29T16:37:01Z 2022-01-01T00:00:00Z

Title: Microbial metabolic responses and CO2 emissions differentiated by soil water content variation in subarctic tundra soils Authors: Kim, Dockyu; 채남이; Kim, Mincheol; Nam, Sungjin; Kim, Tai Kyoung; Park, Ki-Tae; Lee, Bang Yong; 김응빈; Lee, Hyoungseok Abstract: Recent rapid air temperature increases across the northern-latitude tundra have prolonged permafrost thawing and snow melting periods, resulting in increased soil temperature (Ts) and volumetric soil water content (SWC). Under prolonged soil warming at 8 °C, Alaskan tundra soils were incubated in a microcosm system and examined for the SWC differential influence on the microbial decomposition activity of large molecular weight (MW) humic substances (HS). When one microcosm soil (AKC1-1) was incubated at a constant SWC of 41% for 90 days (T=90) and then SWC was gradually decreased from 41% to 29% for another T=90, the initial HS was partly depolymerized. In contrast, in AKC1-2 incubated at a gradually decreasing SWC from the initial 32% to 10% for T=90 and then increasing to 27% for another T=90, HS depolymerization was undetected. Overall, the microbial communities in AKC1-1 could maintain metabolic activity at sufficient and constant SWC during the initial T=90 incubation. In contrast, AKC1-2 microbes may have been damaged by drought stress during the drying SWC regimen, possibly resulting in the loss of HS decomposition activity, which did not recover even after re-wetting to an optimal SWC range. After T=90, the CO2 production in both treatments was attributed to the increased decomposition of small-MW organic compounds (including aerobic HS-degradative products) within an optimal SWC range (20%？40%). We expect this study to provide new insights into the early effects of warming- and topography-induced SWC variations on the microbial contribution to CO2 emissions via HS decomposition in northern-latitude tundra soil.

2022-01-01T00:00:00Z