https://repository.kopri.re.kr/handle/201206/14799 2026-04-14T23:40:19Z 2026-04-14T23:40:19Z Moon, Jangil Han, Yeongcheol Kim, Songyi Lee, Jeonghoon Hur, Soon Do https://repository.kopri.re.kr/handle/201206/16201 2025-10-27T01:51:01Z 2024-04-01T00:00:00Z

Title: Integrating the controlled evaporation mixer with cavity ring-down spectroscopy for enhanced water vapor isotope calibration Authors: Moon, Jangil; Han, Yeongcheol; Kim, Songyi; Lee, Jeonghoon; Hur, Soon Do Abstract: Accurate measurement of water vapor isotopes (delta 18O and delta 2H) is fundamental for advancing our understanding of the hydrological cycle and improving hydrological model accuracy. This study introduces an innovative calibration methodology using a controlled evaporation mixer (CEM) for determining stable isotopic ratios in atmospheric water vapor via cavity ring-down spectroscopy. The CEM technique reliably produces a stable water vapor stream, crucial for enhancing the precision and accuracy of isotopic measurements. Its rapid adaptation to changes in water vapor concentration and compatibility with different water standards enhance calibration reliability. Demonstrated reproducibility in generating water vapor across a broad concentration range from 900 to over 25,000 ppmv, coupled with a substantial reduction in memory effects, makes this approach highly effective in both laboratory and field settings. This calibration advancement greatly enhances research capabilities for continuous atmospheric water vapor analysis, providing deeper insights into hydrological processes and atmospheric dynamics.

2024-04-01T00:00:00Z Han, Yeongcheol https://repository.kopri.re.kr/handle/201206/15561 2024-08-08T01:26:59Z 2024-02-29T00:00:00Z

Title: Observation and understanding of changes in water stable isotope composition in the polar water cycle Authors: Han, Yeongcheol

2024-02-29T00:00:00Z 나지성 Davis Peter E. D. 김병훈 Jin, Emilia Kyung Lee, Won Sang https://repository.kopri.re.kr/handle/201206/14929 2023-12-06T16:38:49Z 2023-01-01T00:00:00Z

Title: Ice Shelf Water Structure Beneath the Larsen C Ice Shelf in Antarctica Authors: 나지성; Davis Peter E. D.; 김병훈; Jin, Emilia Kyung; Lee, Won Sang Abstract: Understanding ice shelf water (ISW) structure is crucial for studying the basal melting of ice shelves. In this study, we performed large-eddy simulation experiments to assess ISW structure and basal melt patterns under different current velocity scenarios observed in the Larsen C ice shelf, Antarctica. The LES results revealed that the thickness of ISW is primarily determined by the meridional velocity (perpendicular to the grounding line), while the zonal velocity influences the potential temperature and salinity of ISW. We found that a key parameter determining the basal melt rate was northward meltwater advection which originates from variances in meltwater generation. This advection, in turn, leads to the tilted isopycnals and the potential for thermohaline interleaving in a diffusive convection regime. The different slopes of isopycnals induce distinct heat fluxes, resulting in different basal melt rates far from and near the grounding line (similar to 0.44 and 1.59 m yr-1, respectively). The loss of ice mass from the Antarctic ice sheet is accelerating, posing a threat to human lives through global sea level rise. Understanding ice shelf water (ISW), which refers to seawater below freezing temperature, is crucial as it directly or indirectly influences basal ice melting. However, direct observations are extremely challenging, leaving this understanding unclear. To tackle this issue, we utilized a numerical model to gain insight into the fundamental characteristics of ISW. We demonstrated that the direction and magnitude of ocean currents beneath the ice shelf play a significant role in determining the thickness and properties of ISW. Moreover, the key factor in basal melting was the northward movement of meltwater from intense ice melting regions near the grounding line. This movement determined the spatial distribution of ocean temperature and salinity. The horizontal gradient of ocean temperature and salinity induces mixing and horizontal intrusion. Interestingly, these mixing and intrusion phenomena occur in opposite directions, resulting in a wiggling pattern in the velocity profile. The main findings of our study will contribute to the formulation of a parameterization for basal melting, which can be incorporated into large-scale ocean models or ice sheet dynamics models. Direction and magnitude of ocean currents beneath an Larsen C ice shelf affect the ice shelf water thickness and propertiesNorthward meltwater advection causes 0.052 degrees C difference of thermal drivings with different melt rates far from and near the grounding lineOcean heat intrusion to ice shelf base is induced by Ekman dynamics and thermohaline interleaving by tilted isopycnals

2023-01-01T00:00:00Z