• Title/Summary/Keyword: Climate conditions

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One-month lead dam inflow forecast using climate indices based on tele-connection (원격상관 기후지수를 활용한 1개월 선행 댐유입량 예측)

  • Cho, Jaepil;Jung, Il Won;Kim, Chul Gyium;Kim, Tae Guk
    • Journal of Korea Water Resources Association
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    • v.49 no.5
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    • pp.361-372
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    • 2016
  • Reliable long-term dam inflow prediction is necessary for efficient multi-purpose dam operation in changing climate. Since 2000s the teleconnection between global climate indices (e.g., ENSO) and local hydroclimate regimes have been widely recognized throughout the world. To date many hydrologists focus on predicting future hydrologic conditions using lag teleconnection between streamflow and climate indices. This study investigated the utility of teleconneciton for predicting dam inflow with 1-month lead time at Andong dam basin. To this end 40 global climate indices from NOAA were employed to identify potential predictors of dam inflow, areal averaged precipitation, temperature of Andong dam basin. This study compared three different approaches; 1) dam inflow prediction using SWAT model based on teleconneciton-based precipitation and temperature forecast (SWAT-Forecasted), 2) dam inflow prediction using teleconneciton between dam inflow and climate indices (CIR-Forecasted), and 3) dam inflow prediction based on the rank of current observation in the historical dam inflow (Rank-Observed). Our results demonstrated that CIR-Forecasted showed better predictability than the other approaches, except in December. This is because uncertainties attributed to temporal downscaling from monthly to daily for precipitation and temperature forecasts and hydrologic modeling using SWAT can be ignored from dam inflow forecast through CIR-Forecasted approach. This study indicates that 1-month lead dam inflow forecast based on teleconneciton could provide useful information on Andong dam operation.

Negative Effect of Abnormal Climate on the Fruits Productivity - Focusing on the Special Weather Report - (이상기후가 과수 생산성에 미치는 악영향 - 기상특보 발효횟수를 중심으로 -)

  • Jeong, Jae Won;Kim, Seongsup;Lee, In Kyu;So, Namho;Ko, Hyeon Seok
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.4
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    • pp.305-312
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    • 2018
  • The crops cultivated and consumed in Korea require specific climate conditions corresponding to their own growth characteristics. This study aims to analyze the relationship between climate change and agricultural productivity. According to growing concern about climate change internationally, many agricultural studies are developing technology to prevent damage from climate change. Before developing technology, we should figure out what kind of crop gets huge damage and how much caused by climate change. In the context of agricultural economics, we can define the reduction of agricultural product yield as a decline in productivity. As a result, this study analyzes the effects of climate change on agricultural productivity using Stochastic Frontier Analysis model. There are several kinds of climate change phenomena that increase the inefficiency of production. In other words, there are several kinds of crops that get negative influence by climate change. The result of this study can be used as basic guideline for producers to prepare for changing weather prior to developing disaster tolerance technology coping actively with special weather report.

A Study on the Infrared Signature of a Naval Ship under the Marine Climate (함정 표면 적외선 신호에 대한 해양기상 영향분석)

  • Kim, Yoon-Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.3
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    • pp.264-272
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    • 2012
  • A study on the IR(InfraRed) signature of a naval ship has been performed using well known IR signature analysis software, ShipIR/NTCS. Variations of the IR signature radiated from skins of a naval ship have been investigated according to the monthly averaged marine climate conditions. An unclassified destroyer model with and without applying the washdown system was applied to compare the influence on the signature under the background changes. The marine background models were created from the observed data by a buoy of Korea Meterological Administration(KMA). The sensitivity of the ship signature against the climate variables such as air temperature, sea temperature, relative humidity has been studied as well. The seasons which show extreme(max, min) skin signature change by whether the washdown is applied or not. The sensitivities of the air temperature and the sea temperature for a dry-ship reversed by applying the washdown on the ship surfaces.

The Impact of Abrupt Climate Change on the Marine Ecosystem in the East Sea

  • Shin, Im-Chul;Yi, Hi-Il;Chung, Hyo-Sang;Kwon, Won-Tae;Chun, Jong-Hwa;Oh, Hyun-Taek
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.1-7
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    • 2003
  • Environmental changes caused by the abrupt climatic change are one of the important issues in the scientific community. In the East Sea, abrupt climatic shift, called Younger Dryas, is identified. The age of the Younger Dryas cold episode occurred at 11.2 ka. Overall, changes in circulation and bottom water conditions occurred during the Younger Dryas cold episode in the study area. Especially, climatic transition from meltwater spike to the Younger Dryas cold episode is characterized by significant shifts of oxygen isotope values, the coiling ratios of Neogloboquadrina pachyderma, and the planktonic foraminifers abundances. The impact of abrupt climate change on the ecosystem is very significant. In the East Sea, the calcium carbonate secreting organism(foraminifers) is replaced by silicon dioxide secreting organisms(diatom, radiolarian) after the abrupt and severe cold climatic event. Based on the Doctrine of Uniformitarianism, at least climate change for the next 100 years would be severely influence on the marine ecosystem.

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Prediction of Land-cover Change Based on Climate Change Scenarios and Regional Characteristics using Cluster Analysis (기후변화 시나리오에 따른 미래 토지피복변화 예측 및 군집분석을 이용한 지역 특성 분석)

  • Oh, Yun-Gyeong;Choi, Jin-Yong;Yoo, Seung-Hwan;Lee, Sang-Hyun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.6
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    • pp.31-41
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    • 2011
  • This study was conducted to predict future land-cover changes under climate change scenarios and to cluster analysis of regional land-cover characteristics. To simulate the future land-cover according to climate change scenarios - A1B, A2, and B1 of the Special Report on Emissions Scenarios (SRES), Dyna-CLUE (Conversion of Land Use Change and its Effects) was applied for modeling of competition among land-use types in relation with socioeconomic and biophysical driving factors. Gyeonggi-do were selected as study areas. The simulation results from 2010 to 2040 suggested future land-cover changes under the scenario conditions. All scenarios resulted in a gradual decrease in paddy area, while upland area continuously increased. A1B scenario showed the highest increase in built-up area, but all scenarios showed only slight changes in forest area. As a result of cluster analysis with the land-cover component scores, 31 si/gun in Gyeonggi-do were classified into three clusters. This approach is expected to be useful for evaluating and simulating land-use changes in relation to development constraints and scenarios. The results could be used as fundamental basis for providing policy direction by considering regional land-cover characteristics.

Spatial Changes in Work Capacity for Occupations Vulnerable to Heat Stress: Potential Regional Impacts From Global Climate Change

  • Kim, Donghyun;Lee, Junbeom
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.1-9
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    • 2020
  • Background: As the impact of climate change intensifies, exposure to heat stress will grow, leading to a loss of work capacity for vulnerable occupations and affecting individual labor decisions. This study estimates the future work capacity under the Representative Concentration Pathways 8.5 scenario and discusses its regional impacts on the occupational structure in the Republic of Korea. Methods: The data utilized for this study constitute the local wet bulb globe temperature from the Korea Meteorological Administration and information from the Korean Working Condition Survey from the Occupational Safety and Health Research Institute of Korea. Using these data, we classify the occupations vulnerable to heat stress and estimate future changes in work capacity at the local scale, considering the occupational structure. We then identify the spatial cluster of diminishing work capacity using exploratory spatial data analysis. Results: Our findings indicate that 52 occupations are at risk of heat stress, including machine operators and elementary laborers working in the construction, welding, metal, and mining industries. Moreover, spatial clusters with diminished work capacity appear in southwest Korea. Conclusion: Although previous studies investigated the work capacity associated with heat stress in terms of climatic impact, this study quantifies the local impacts due to the global risk of climate change. The results suggest the need for mainstreaming an adaptation policy related to work capacity in regional development strategies.

Study on the micro-scale simulation of wind field over complex terrain by RAMS/FLUENT modeling system

  • Li, Lei;Zhang, Li-Jie;Zhang, Ning;Hu, Fei;Jiang, Yin;Xuan, Chun-Yi;Jiang, Wei-Mei
    • Wind and Structures
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    • v.13 no.6
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    • pp.519-528
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    • 2010
  • A meteorological model, RAMS, and a commercial computational fluid dynamics (CFD) model, FLUENT are combined as a one-way off-line nested modeling system, namely, RAMS/FLUENT system. The system is experimentally applied in the wind simulation over a complex terrain, with which numerical simulations of wind field over Foyeding weather station located in the northwest mountainous area of Beijing metropolis are performed. The results show that the method of combining a meteorological model and a CFD model as a modeling system is reasonable. In RAMS/FLUENT system, more realistic boundary conditions are provided for FLUENT rather than idealized vertical wind profiles, and the finite volume method (FVM) of FLUENT ensures the capability of the modeling system on describing complex terrain in the simulation. Thus, RAMS/FLUENT can provide fine-scale realistic wind data over complex terrains.

An Experimental Study on Difference of Thermal Sensation by Radiant Floor Heating (바닥난방 복사열에 의한 온열감 차이에 대한 실험연구)

  • Choi, Yoon-Jung;Shim, Hyun-Suk;Jeong, Youn-Hong
    • KIEAE Journal
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    • v.7 no.5
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    • pp.65-71
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    • 2007
  • The purpose of this study was to analyze the difference of thermal sensation by radiant floor heating as ecological design element. The experimental investigations were carried out in climate chamber, and subjects were 34 college-age females in good health. The experimental variable was radiant heat by floor heating, and experimental controlled conditions were indoor temperature, relative humidity, and air velocity in climate chamber and clothing value and activity of subjects. The results are as follows. (1) Indoor temperature($21{\pm}0.5^{\circ}C$) in climate chamber were maintained as controlling. Clothing values of the subjects were controlled as average 0.73 clo. In the floor heating-off, globe temperature was average $23.2^{\circ}C$(22.4~24.1), but in the floor heating-on, globe temperature was average $24.8^{\circ}C$(23.0~25.5). (2) In the floor heating-off, thermal sensation rating was average -1.03(slightly cool), in the floor heating-on, thermal sensation rating was average +1.03(slightly warm). (3) There were the differences of thermal sensation by radiant floor heating although indoor temperatures were maintained in an equal state. (4) The thermal sensation rating was tending upward according as the globe temperature was getting higher.

Simulation of Regional Climate over East Asia using Dynamical Downscaling Method

  • Oh, Jai-Ho;Kim, Tae-Kook;Min, Young-Mi
    • Proceedings of the Korea Water Resources Association Conference
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    • 2002.05b
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    • pp.1187-1194
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    • 2002
  • In this study, we have simulated regional climate over East Asia using dynamical downscaling For dynamic downscaling experiments for regional climate simulation, MM5method. with 27 km horizontal resolution and 18 layers of sigma-coordinate in vertical is nested within global-scale NCEP reanalysis data with 2.5。${\times}$2.5。 resolution in longitude and latitude. In regional simulation, January and July, 1979 monthly mean features have been obtained by both continuous integration and daily restart integration driven by updating the lateral boundary forcing at 6-hr intervals from the NCEP reanalysis data using a nudging scheme with the updating design of initial and boundary conditions in both continuous and restart integrations. In result, we may successfully generated regional detail features which might be forced by topography, lake, coastlines and land use distribution from a regional climate. There is no significant difference in monthly mean features either integrate continuously or integrate with daily restart. For climatologically long integration, the initial condition may not be significantly important. Accordingly, MM5 can be integrated for a long period without restart frequently, if a proper lateral boundary forcing is given.

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Performance Comparison of Automotive Air conditioning System by using R134a and R152a (R134a와 R152a 냉매를 이용한 자동차용 에어컨 시스템의 성능 비교)

  • Kim, Jeong-Su;Nam, Su-Byung;Lee, Dae-Woong;Yoo, Seong-Yeon;Kim, Jin-Hyuck
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.9-14
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    • 2006
  • This study presented the feasibility of R152a refrigerant as an alternative of R134a which is used in the current automobile air conditioning system. The performance of air conditioning system installed in the actual vehicle was tested using the climate wind tunnel. The experiments were conducted at various refrigerant charge quantities and various driving conditions such as city traffic, highway traffic and parking. Same components and lubricant were used for both R134a and R152a system. The effects of air set values of thermal expansion valve on the performance were also investigated. In case of the R152a system, refrigerant charge quantity can be reduced about 20%, better performance and superior compressor durability is expected due to the lower discharge pressure compared to the R134a system.

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