간행물
한국지구과학회지 KCI 등재 The Journal of The Korean Earth Science Society
- 발행기관 한국지구과학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-6692 (Print)2287-4518 (Online)
- 수록기간 1979 ~ 2024
- 주제분류 자연과학 > 지구과학 자연과학 분류의 다른 간행물
- 십진분류KDC 450DDC 550
권호리스트/논문검색
제45권 제4호 (2024년 8월) 11건
1.
2024.08
구독 인증기관 무료, 개인회원 유료
We explored the effect of galaxy-galaxy interaction on the FIR-radio correlation of star-forming galaxies by comparing the qFIR parameter distribution between interacting and non-interacting galaxies. Our sample galaxies were selected from the SDSS Stripe 82 region, where relatively deep optical images are available in addition to ancillary FIR and radio data. The qFIR values were 2.73±0.49 and 2.53±0.90 for interacting and non-interacting galaxies, respectively. The t-test results indicated that the difference in qFIR values between the two categories is not statistically significant. Our findings align with those of previous studies suggesting that either FIR excess or radio excess occurs only transiently during brief timescales in the merger stages, rather than persisting throughout the majority of merger events identified by features such as tidal tails or double nuclei.
4,500원
2.
2024.08
구독 인증기관 무료, 개인회원 유료
We study quasi-spherical, supersonic accretion flows around black holes using high-accuracy numerical simulations. We describe a code, the Lagrangian Total Variation Diminishing (TVD), and a remap routine to address a specific issue in the Advection Dominated Accretion Flow (ADAF) that is, appropriately handling the angular momentum even near the inner boundary. The Lagrangian TVD code is based on an explicit finite difference scheme on mass-volume grids to track fluid particles with time. The consequences are remapped on fixed grids using the explicit Eulerian finitedifference algorithm with a third-order accuracy. Test results show that one can successfully handle flows and resolve shocks within two to three computational cells. Especially, the calculation of a hydrodynamical accretion disk without viscosity around a black hole shows that one can conserve nearly 100% of specific a ngular momentum in one-and twodimensional cylindrical coordinates. Thus, we apply this code to obtain a numerically similar ADAF solution. We perform simulations, including viscosity terms in one-dimensional spherical geometry on the non-uniform grids, to obtain greater quantitative consequences and to save computational time. The error of specific angular momentum in Newtonian potential is less than 1% between r~10rs and r~10 4 rs, where rs is sink size. As Narayan et al. (1997) suggested, the ADAFs in pseudo-Newtonian potential become supersonic flows near the black hole, and the sonic point is rsonic~5.3rg for flow with α =0.3 and =1 .5. Such simulations indicate that even the ADAF with =5/3 is differentially rotating, as Ogilvie (1999) indicated. Hence, we conclude that the Lagrangian TVD and remap code treat the role of viscosity more precisely than the other scheme, even near the inner boundary in a rotating accretion flow around a nonrotating black hole.
4,300원
3.
2024.08
구독 인증기관 무료, 개인회원 유료
Young-Joo Kwon, Hyun-Ju Ban, Sumin Ryu, Suna Jo, Han-Sol Ryu, Yerin Kim, Jeong-Eun Park, Yun-Jeong Choi, Kyung-Hoon Han, Yeonjun Kim, Sungwook Hong
This study proposes a soil moisture retrieval method from ground reflection signals received by Global Positioning System (GPS) antenna modules consisting of an up-looking (UP) right-hand circular polarization (RHCP) and two down-looking (DW) RHCP and left-hand circular polarization (LHCP) signals. Field experiments at four different surface types (asphalt, grassland, dry soil, and moist soil) revealed that the DW RHCP and LHCP signals are affected by antenna height and multipath interference signals. The strength differences between the DW LHCP and UP RHCP signals were in good agreement with the DW LHCP signals. Methodologically, this study applied a spectrum analysis to the detrended surface-reflected signals for RHCP and LHCP. The study indicated that the down-looking antenna exhibited greater sensitivity to reflected GPS signals than the up-looking antenna. We demonstrated the feasibility of estimating soil moisture using GPS signals, by comparing LHCP signals received by the down-looking antenna with theoretical values. This study presents a novel method for estimating soil moisture in vegetated areas, leveraging the advantage of crosspolarization comparisons to achieve stronger signal strength than single-polarization reflection signals. With further research, including long-term observations and detailed analysis, the proposed method has the potential to enhance performance significantly.
4,600원
4.
2024.08
구독 인증기관 무료, 개인회원 유료
Young-Joo Kwon, Hyun-Ju Ban, Sumin Ryu, Suna Jo, Han-Sol Ryu, Yerin Kim, Jeong-Eun Park, Yun-Jeong Choi, Kyung-Hoon Han, Yeonjun Kim, Sungwook Hong
Black ice, a thin and nearly invisible ice layer on roads and pavements, poses a significant danger to drivers and pedestrians during winter due to its transparency. We propose an efficient black ice detection system and technique utilizing Global Positioning System (GPS)-reflected signals. This system consists of a GPS antenna and receiver configured to measure the power of GPS L1 band signal strength. The GPS receiver system was designed to measure the signal power of the Right-Handed Circular Polarization (RHCP) and Left-Handed Circular Polarization (LHCP) from direct and reflected signals using two GPS antennas. Field experiments for GPS LHCP and RHCP reflection measurements were conducted at two distinct sites. We present a Normalized Polarized Reflection Index (NPRI) as a methodological approach for determining the presence of black ice on road surfaces. The field experiments at both sites successfully detected black ice on asphalt roads, indicated by NPRI values greater than 0.1 for elevation angles between 45o and 55o. Our findings demonstrate the potential of the proposed GPS-based system as a cost-effective and scalable solution for large-scale black ice detection, significantly enhancing road safety in cold climates. The scientific significance of this study lies in its novel application of GPS reflection signals for environmental monitoring, offering a new approach that can be integrated into existing GPS infrastructure to detect widespread black ice in real-time.
4,000원
5.
2024.08
구독 인증기관 무료, 개인회원 유료
The ocean is linked to long-term climate variability, but there are very few methods to assess the short-term performance of forecast models. This study analyzes the short-term prediction performance regarding ocean temperature and salinity of the Global Seasonal prediction system version 5 (GloSea5). GloSea5 is a historical climate re-creation (2001-2010) performed on the 1st, 9th, 17th, and 25th of each month. It comprises three ensembles. High-resolution hindcasts from the three ensembles were compared with the Array for Real-Time Geostrophic Oceanography (ARGO) float data for the period 2001-2010. The horizontal position was preprocessed to match the ARGO float data and the vertical layer to the GloSea5 data. The root mean square error (RMSE), Brier Score (BS), and Brier Skill Score (BSS) were calculated for short-term forecast periods with a lead-time of 10 days. The results show that sea surface temperature (SST) has a large RMSE in the western boundary current region in Pacific and Atlantic Oceans and Antarctic Circumpolar Current region, and sea surface salinity (SSS) has significant errors in the tropics with high precipitation, with both variables having the largest errors in the Atlantic. SST and SSS had larger errors during the fall for the NINO3.4 region and during the summer for the East Sea. Computing the BS and BSS for ocean temperature and salinity in the NINO3.4 region revealed that forecast skill decreases with increasing lead-time for SST, but not for SSS. The preprocessing of GloSea5 forecasts to match the ARGO float data applied in this study, and the evaluation methods for forecast models using the BS and BSS, could be applied to evaluate other forecast models and/or variables.
4,200원
6.
2024.08
구독 인증기관 무료, 개인회원 유료
In the mid-eastern part of the Yellow Sea, large-scale shelf ridges originated from erosion on sand-mud successions that have been presently eroded by strong tidal currents. A three-layered in situ geoacoustic model is provided down to 50 m for the subbottom sedimentary succession of a 45 m water depth using the Hamilton method. The succession is divisible into two-type units of Type-A and Type-B using high-resolution seismic profiles with a deep-drilled YSDP-104 core of 44.0 m in depth below the seafloor. Type-A unit mainly comprises sandy or gravelly sediments, whereas Type-B unit mostly consists of tidal muddy sediments with some thinner sand beds. P-wave speed values are positively compatible with the mean grain size and sediment type of the core sediments. For actual modeling, the geoacoustic property values of the models were compensated to in situ depth values below the seafloor. The detailed geoacoustic model contributes to simulating sound transmission through the sedimentary successions in erosional shelf ridges of variable geoacoustic properties distributed in shallow-water environments of the mid-eastern Yellow Sea.
4,200원
7.
2024.08
구독 인증기관 무료, 개인회원 유료
We aimed to evaluate the effectiveness of ensemble optimal interpolation (EnOI) in improving the analysis of significant wave height (SWH) within wave models using satellite-derived SWH data. Satellite observations revealed higher SWH in mid-latitude regions (30o to 60o in both hemispheres) due to stronger winds, whereas equatorial and coastal areas exhibited lower wave heights, attributed to calmer winds and land interactions. Root mean square error (RMSE) analysis of the control experiment without data assimilation revealed significant discrepancies in high-latitude areas, underscoring the need for enhanced analysis techniques. Data assimilation experiments demonstrated substantial RMSE reductions, particularly in high-latitude regions, underscoring the effectiveness of the technique in enhancing the quality of analysis fields. Sensitivity experiments with varying ensemble sizes showed modest global improvements in analysis fields with larger ensembles. Sensitivity experiments based on different decorrelation length scales demonstrated significant RMSE improvements at larger scales, particularly in the Southern Ocean and Northwest Pacific. However, some areas exhibited slight RMSE increases, suggesting the need for region-specific tuning of assimilation parameters. Reducing the observation error covariance improved analysis quality in certain regions, including the equator, but generally degraded it in others. Rescaling background error covariance (BEC) resulted in overall improvements in analysis fields, though sensitivity to regional variability persisted. These findings underscore the importance of data assimilation, parameter tuning, and BEC rescaling in enhancing the quality and reliability of wave analysis fields, emphasizing the necessity of region-specific adjustments to optimize assimilation performance. These insights are valuable for understanding ocean dynamics, improving navigation, and supporting coastal management practices.
4,600원
8.
2024.08
구독 인증기관 무료, 개인회원 유료
Alluvial beds are intimately associated with electrical properties related to soil types, including clay mineral content, porosity, and water content. The hydraulic property governs water movement and storage in alluvial beds. This study revealed electrical resistivity and hydraulic properties in space and time in relation to the hydrogeological data, groundwater pumping, and rainfall infiltration into the alluvial bed located in Daesan-myeon, Changwon City. An electrical resistivity survey with electrode spacings of 2 and 4m using a dipole-dipole array indicates that electrical resistivity changes in the alluvial bed depend on groundwater pumping and rainfall events. Additionally, rainfall infiltration varies with hydraulic conductivity in the shallow zone of the alluvial bed. The 2 m electrode spacing survey confirms that electrical resistivity values decrease at shallow depths, corresponding with rainfall and increased water content in the soil, indicating rainfall infiltration approximately 1-2 m below the land surface. The 4m electrode spacing survey reveals that hydraulic conductivity (K) values and electrical resistivity (ρ) values display an inverse relationship from the surface to the water table (approximately 9 m) and at deeper levels than the water table. Notably, ρ values are impacted by pumping around the depth of the water table at 9 m. This study suggests that time-lapsed electrical resistivity surveys in space and time could be effective tools for detecting the impact of rainfall and pumping, as well as hydraulic conductivity in shallow alluvial beds.
4,600원
9.
2024.08
구독 인증기관 무료, 개인회원 유료
This study aimed to explore the characteristics and dimensions of of systematic functional gestures employed by pre-service Earth science teachers during instructional sessions. Data were collected from eight students enrolled in a university’s Department of Earth Science Education. The data included lesson plans, activity sheets, and recordings of one class session from participants. The analysis, conducted using the systemic functional multimodal discourse analysis framework, categorized gestures into scientific and social functional dimensions. Further subdivision identified meta gestures, analytical gestures, and interrelated gestures. Additionally, pre-service teachers used gestures to explain scientific concepts, concretely represent ideas and facilitate communication during instruction. This study emphasizes the nonverbal strategies used by pre-service Earth science teachers, highlighting the importance of noverbal communication in teachers’ professional development and the need for its integration into education. It also establishes a systematic conceptual framework for understanding gestures in the instructional context.
4,800원
10.
2024.08
구독 인증기관 무료, 개인회원 유료
This study investigated the perceptions of elementary school preservice teachers in their 4th year at KEducation University, an elementary school teacher-training institution, on the nature of science (NOS). To examine the differences in elementary school preservice teachers’ perceptions of NOS according to their high school career aptitude, we conducted in-depth interviews with two students each in the humanities and social sciences (HS) and natural sciences (NS) based on the subjects that they had taken while attending high school. For this purpose, we used the Views of Nature of Science Form C (VNOS-C) and Views about Scientific Inquiry (VASI) questionnaires, which were reconfigured. The main research results were that the elementary school preservice teachers showed a positivistic perspective on the NOS, validity of scientific knowledge, difference between theory and law, and social and cultural embeddedness of science. However, they had a latest perspective on the tentativeness of scientific knowledge, observation and inference, and the role of imagination and creativity. In particular, there were clear differences in perception between HS and NS teachers in the areas of tentativeness of scientific knowledge and understanding of observation and inference. Based on these research results, educational implications for improving the science education competencies of preservice elementary school teachers were proposed.
4,300원
11.
2024.08
구독 인증기관 무료, 개인회원 유료
Many risk-related issues within the realm of science education have been addressed through science-technologyrelated socioscientific issues (SSI) education. It has been established that the topics categorized as SSI are interconnected with risk-related issues. These topics emphasize numerous points of convergence with the goals of SSI education, particularly in understanding and analyzing risks, including risk assessment, risk management, and risk decision-making. Such understanding can aid in grasping the complexity of SSI based on risk-related issues and facilitate informed decision-making by structuring debates. Although there has been discourse on the need for education aimed at future survival and reflection on the responsibilities and roles of education in risk-prone societies, concepts or strategies related to actual risk responses are rarely addressed in science education and schools. Education tailored to risk-prone societies is not yet well established. This study explored the incorporation of climate change risk education into science education. A framework for climate change risk education was developed, encompassing seven elements, with corresponding definitions and examples. The researchers applied this framework to evaluate the extent to which climate change risk education is integrated into the current science curriculum of Korea. Additionally, SSI lesson scenarios related to climate change were analyzed using this risk education framework to determine the types and extent of risk education incorporated. The findings underscore the importance of teaching climate change risk education to equip students for rational decision-making.
5,100원
