• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.6
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• pp.509-514
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• 2012

In this research, a heat pump system with a heat source network is suggested which utilizes solar heat and ground heat as heat source for cooling and heating. This paper describes the summary of the suggested system and the results of the annual energy simulation. The heating and cooling loads, the electric consumption and the COP were calculated by TRNSYS 16 and evaluated in the cases of different local conditions and different system compositions. In the results, the superiority of the suggested system has been quantitatively evaluated comparing with the conventional heat pump system using one heat source. Furthermore, it was more significant in cold climate, in which the heating COP was 146% increased compared the air source heat pump system, than it in subtropical climate, 119% increased.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.1043-1056
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• 2006

Our ultimate purpose is to investigate the potential change in regional surface climate due to the global warming and to produce higher quality regional surface climate information over the Korean peninsula for comprehensive impact assessment. Toward this purpose, we carried out two 30-year long experiments, one for present day conditions (covering the period 1971-2000) and one for near future climate conditions (covering the period 2021-2050) with a regional climate model (RegCM3) using a one-way double-nested system. In order to obtain the confidence in a future climate projection, we first verify the model basic performance of how the reference simulation is realistic in comparison with a fairly dense observation network. We then examine the possible future changes in mean climate state as well as in the frequency and intensity of extreme climate events to be derived by difference between climate condition as a baseline and future simulated climate states with increased greenhouse gas. Emphasis in this study is placed on the high-resolution spatial/temporal aspects of the climate change scenarios under different climate settings over Korea generated by complex topography and coastlines that are relevant on a regional scale.

• The Korean Journal of Quaternary Research
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• v.21 no.2
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• pp.64-67
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• 2007

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.192-203
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• 2011

The CERES-Barley crop simulation model was used to assess the impacts of climate change on the potential yield of winter naked barley in Korea. Fifty six sites over the southern part of the Korean Peninsula were selected to compare the climate change impacts in various climatic conditions. Based on the A1B climate change scenarios of Korea, the present climatological normal (1971-2000) and the three future ones (2011-2040, 2041-2070, and 2071-2100) were considered in this study. The three future normals were divided by three environmental conditions with changes in: (1) temperature only, (2) carbon dioxide concentration only, and (3) both temperature and carbon dioxide concentration. The agreement between the observed and simulated outcomes was reasonable with the coefficient of determination of grain yield to be 0.78. We concluded that the CERES-Barley model was suitable for predicting climate change impacts on the potential yield of winter naked barley. The effect of the increased temperature only with the climate change scenario was negative to the potential yield of winter naked barley, which ranges from -34 to -9% for the three future normals. However, the effect of the elevated carbon dioxide concentration only on the potential yield of winter naked barley was positive, ranging from 6 to 31% for the three future normals. For the elevated conditions of both temperature and carbon dioxide concentration, the potential yields increased by 8, 15, and 13% for the 2011-2040, 2041-2070, and 2071-2100 normals, respectively.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.877-886
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• 2022

This study was carried out to analyze how the flow and water quality of the Sangsa Lake (juam control basin) change according to future climate change and what countermeasures are needed. Aquatic Ecosystem Model) was used in conjunction. As climate change scenarios, RCP (Representative Concentration Pathways) 4.5 and RCP 8.5 scenarios of AR5 (5th Assessment Report) according to the Intergovernmental Panel on Climate Change (IPCC) were used. For the climate change scenario, detailed data on the Sangsa Lake basin were used by the Korea Meteorological Administration, and after being evaluated as a correction and verification process for the 10-year period from 2012 to 2021, the present, 2025-2036, 2045- The summer period from June to August and the winter period from December to February were analyzed separately for each year by dividing it into 2056 and 2075-2086. RCP 8.5 was higher than RCP 4.5 as an arithmetic mean for the flow rate of the watershed of the superior lake for the entire simulation period, and TN and TP also showed a tendency to be higher at RCP 4.5. However, in RCP 8.5, the outflow of pollutants decreased during the dry season and the outflow of pollutants increased during the summer, indicating that the annual pollutant outflow was concentrated during the flood season, and it is analyzed that countermeasures are needed.

• Journal of Korea Water Resources Association
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• v.42 no.6
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• pp.433-443
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• 2009

For the better understanding of the temporal characteristics of soil water, this study is to suggest a stochastic soil water model and to apply it for impact assessment of climate change. The loss function is divided into 3 stages for more specified comprehension of the probabilistic behavior of soil water, and especially, the soil water model considering the stochastic characteristics of precipitation is developed in order to consider the variation of climatic factors. The simulation result of soil water model confirms that the proposed soil water model can re-generate the observation properly, and it also proves that the soil water behaves with consistent cycle based on the precipitation pattern. Moreover, with the simulation results with a climate change scenario, it can be predicted that the future soil water will have higher variations than present soil water.

• Atmosphere
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• v.17 no.3
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• pp.241-253
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• 2007

This paper investigates summer precipitation change in East Asia according to switching surface boundary condition over South Korea and Shantung. Simulations are carried out by ECHO-G/S for 20 years (1980-1999). Surface condition over both areas in ECHO-G/S is represented by ocean (OCN experiment). In OCN experiment, the summer precipitation is considerably underestimated around the Korean peninsula (the dry region) and overestimated over the eastern Tibetan Plateau (the wet region). It may be related that the lack of the heat sources from the unrealistically prescribed land-sea mask weakens northward expansion of rainband and the development of convective precipitation. Moreover the simulated rainband retreats before June in connection with the early genesis of summer monsoon circulation. The systematic bias of the summer precipitation over the dry and wet regions are reduced comparing with the OCN experiment when the land-sea masks over South Korea and Shantung are realistically considered as land (LND experiment). These improvements can be explained by the thermodynamical dissimilarity between land and ocean. Enhanced warming by switching the areas from sea to land has led to develop the thermal low over Yellow Sea with the cyclonic circulation. Thus, this cyclonic circulation supports moistures from the south to the dry region and blocks to the wet region. The heat transport from the land surface to atmosphere plays a key role in the developing convective precipitation in local scale and maintaining the precipitation and the rainband. Therefore, this results indicate that the design of the realistic land-sea distribution is required for the accurate simulation of the regional precipitation.

• Environmental and Resource Economics Review
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• v.17 no.2
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• pp.287-311
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• 2008

This paper is designed to examine how the global timber market impacted by climate change would affect global warming through the carbon flux of forests. For this purpose, we integrated the modified TSM 2000 and the extended TCM in order to simulate the projection of net carbon release of forests from 1995 to 2085. On the basis of the simulation results under normal demand growth scenario, we identified that the global timber market impacted by climate change ameliorates the atmospheric carbon about 3.60% of carbon dioxide concentration in 1990 over 90 years. This implies that the global timber market impacted by climate change has a negative feedback effect on global warming over 90 years. For sensitivity analysis, we performed these simulation procedure under high demand growth scenario and very high demand growth scenario.

• Journal of Climate Change Research
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• v.4 no.2
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• pp.77-93
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• 2013

Global warming accelerates both carbon (C) input through increased forest productivity and heterotrophic C emission in forest soils, and a future trend in soil C dynamics is uncertain. In this study, the Korean forest soil carbon model (KFSC model) was applied to 1,467,458 ha of Pinus densiflora forests in Korea to predict future C dynamics under RCP 8.5 climate change scenario (RCP scenario). Korea was divided into 16 administrative regions, and P. densiflora forests in each region were classified into six classes by their stand ages : 1 to 10 (I), 11 to 20 (II), 21 to 30 (III), 31 to 40 (IV), 41 to 50 (V), and 51 to 80-year-old (VI+). The forest of each stand age class in a region was treated as a simulation unit, then future net primary production (NPP), soil respiration (SR) and forest soil C stock of each simulation unit were predicted from the 2012 to 2100 under RCP scenario and constant temperature scenario (CT scenario). As a result, NPP decreased in the initial stage of simulation then increased while SR increased in the initial stage of simulation then decreased in both scenarios. The mean NPP and SR under RCP scenario was 20.2% and 20.0% higher than that under CT scenario, respectively. When the initial age class was I, IV, V or VI+, predicted soil C stock under CT scenario was higher than that under RCP scenario, however, the countertrend was observed when the initial age class was II or III. Also, forests having a lower site index showed a lower soil C stock. It suggested that the impact of temperature on NPP was higher when the forests grow faster. Soil C stock under RCP scenario decreased at the end of simulation, and it might be derived from exponentially increased SR under the higher temperature condition. Thus, the difference in soil C stock under two scenarios will be much larger in the further future.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.63-72
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• 2020

Solar-sharing, which is an agricultural photovoltaic system installing solar panels on the upper part of crop growing field, has especially drawn attention. Because paddy fields for cultivating crops are large flat areas, there have been various attempts to utilize solar energy for solar photovoltaic as well as growth of crops in agriculture. Solar-sharing was first proposed in Japan, and has been actively studied for optimization and practical uses. The domestic climate differs from the climate conditions in which the solar-sharing has been widely studied, therefore, it is required to develop the solar-sharing technology suitable for the domestic climate. In this study, a simulation model was developed to analyze the change of solar radiation resulted from the solar-sharing installation. Monthly solar illumination intensity and the change of illumination intensity according to the various conditions of solar panel installation were simulated. The results of monthly illumination analysis differed by altitude of the sun, which was related to season. In addition, it was analyzed that the monthly illumination decreased by up to 42% due to solar-sharing. Accordingly, it is recommended that solar-sharing should be installed as a way to maximize the efficiency of solar photovoltaic system while minimizing the decrease in solar radiation reaching the crops.