• Title/Summary/Keyword: global circulation

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A Comparative Study on General Circulation Model and Regional Climate Model for Impact Assessment of Climate Changes (기후변화의 영향평가를 위한 대순환모형과 지역기후모형의 비교 연구)

  • Lee, Dong-Kun;Kim, Jae-Uk;Jung, Hui-Cheul
    • Journal of Environmental Impact Assessment
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    • v.15 no.4
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    • pp.249-258
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    • 2006
  • Impacts of global warming have been identified in many areas including natural ecosystem. A good number of studies based on climate models forecasting future climate have been conducted in many countries worldwide. Due to its global coverage, GCM, which is a most frequently used climate model, has limits to apply to Korea with such a narrower and complicated terrain. Therefore, it is necessary to perform a study impact assessment of climate changes with a climate model fully reflecting characteristics of Korean climate. In this respect, this study was designed to compare and analyze the GCM and RCM in order to determine a suitable climate model for Korea. In this study, spatial scope was Korea for 10 years from 1981 to 1990. As a research method, current climate was estimated on the basis of the data obtained from observation at the GHCN. Future climate was forecast using 4 GCMs furnished by the IPCC among SRES A2 Scenario as well as the RCM received from the NIES of Japan. Pearson correlation analysis was conducted for the purpose of comparing data obtained from observation with GCM and RCM. As a result of this study, average annual temperature of Korea between 1981 and 1990 was found to be around $12.03^{\circ}C$, with average daily rainfall being 2.72mm. Under the GCM, average annual temperature was between 10.22 and $16.86^{\circ}C$, with average daily rainfall between 2.13 and 3.35mm. Average annual temperature in the RCM was identified $12.56^{\circ}C$, with average daily rainfall of 5.01mm. In the comparison of the data obtained from observation with GCM and RCM, RCMs of both temperature and rainfall were found to well reflect characteristics of Korea's climate. This study is important mainly in that as a preliminary study to examine impact of climate changes such as global warming it chose appropriate climate model for our country. These results of the study showed that future climate produced under similar conditions with actual ones may be applied for various areas in many ways.

Three Reanalysis Data Comparison and Monsoon Regional Analysis of Apparent Heat Source and Moisture Sink (겉보기 열원 및 습기 흡원의 세 재분석 자료 비교와 몬순 지역별 분석)

  • Ha, Kyung-Ja;Kim, Seogyeong;Oh, Hyoeun;Moon, Suyeon
    • Atmosphere
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    • v.28 no.4
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    • pp.415-425
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    • 2018
  • The roles of atmospheric heating formation and distribution on the global circulation are of utmost importance, and those are directly related to not only spatial but also temporal characteristics of monsoon system. In this study, before we clarify the characteristics of apparent heat source <$Q_1$> and moisture sink <$Q_2$>, comparisons of three reanalysis datasets (NCEP2, ERA-Interim, and JRA-55) in its global or regional patterns are performed to clearly evaluate differences among datasets. Considering inter-hemispheric difference of global monsoon regions, seasonal means of June-July-August and December-January-February, which is summer (winter) and winter (summer) in the Northern (Southern) Hemisphere are employed respectively. Here we show the characteristics of eight different regional monsoon regions and find contributions of <$Q_2$> to <$Q_1$> for the regional monsoon regions. Each term in apparent heat source and moisture sink is shown to come from the ERA-Interim dataset, since the ERA-Interim could be representative of three datasets. The NCEP2 data has a different characteristic in the ratio of <$Q_2$> and <$Q_1$> because it overestimates <$Q_1$> compared to the other two different datasets. The Australia monsoon has been performing better over time, while some regional monsoons (South America, North America, and North Africa) have been showing increasing data inconsistency. In addition, the three reanalysis datasets are getting different marching with time, in particular since the early 2000s over South America, North America, and North Africa monsoon regions. The recent inconsistency among the three datasets that may be associated with the global warming hiatus remains unexplored.

Health Impacts of Climate Change and Natural Disaster (기후변화와 자연재난의 건강영향)

  • Kim, Daeseon;Lee, Chulwoo;Vatukela, Jese
    • Journal of Appropriate Technology
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    • v.5 no.2
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    • pp.118-125
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    • 2019
  • Climate change is one part of 17 Sustainable Development Goals (SDGs). According to the Fifth Assessment Report by the Inter- governmental Panel on Climate Change(IPCC) published in 2014, global warming is caused by greenhouse gas (GHG) emissions. The most important GHG is carbon dioxide (CO2), which is released by the burning of fossil fuels and, to a lesser extent, by land use practices, followed by nitrous oxide and methane. IPCC predicts that global temperatures will rise 3.7℃ and sea level will rise 0.63 m by 2099 in the case of no strong restraint. According to the report, we can expect a massive species extinctions, changes in storm and drought cycles, altered ocean circulation, and redistribution of vegetation by global warming. However, climate changes, especially global warming, are the largest potential threat to human health and the source of a number of diseases globally. If climate changes are continued uncontrolled, human health will be adversely affected by the accelerating climate change and the natural disaster induced by climate change. It means we will face more serious conditions of injury, disease, and death related to natural disasters such as flood, drought, heat waves, malnutrition, more allergy, air pollution and climate change related infections related to morbidity and mortality. This review emphasizes on the relationship between global climate changes and human health and provides some suggestions for improvement.

A Study on Area Types of Recycling Agriculture (지역별 순환농업의 유형에 관한 연구)

  • 조익환
    • Korean Journal of Organic Agriculture
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    • v.11 no.3
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    • pp.91-108
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    • 2003
  • So far, we have pursued only convenient and efficient growth of economy, as a result, environment surrounding us has been destroyed and the rights of our existence gotten to be even threatened. We need to ensure our lives and at the same time, need a power with which agriculture undertakes global circulation structure and a power that is able to preserve our environment we live per so. Therefore, in the near future, the final objectives of agriculture structure for 21st century would be to increase productivity of highly developed agricultural products in accordance with the ecosystem and a recycling agriculture. What is a recycling agriculture\ulcorner In the narrow sense, it means provisions-producing- system related to interactive recycle of material among forestry, livestock husbandry and seeding agriculture. In the broad sense, it means to produce credible agricultural product by keeping balanced resources via conversion to complete degradable material of organic wastes produce within rural village. Based on this concept, finally, our goal is to construct the resources recycling community. Environment friendly agriculture ⇒ organic agriculture ⇒ recycling (circulation) agriculture ⇒ construction of community with resources recycling. Therefore, in order to construct recycling agriculture, most of all, it is considered that the following, it should be established reasonable standard amounts for fertilizer, manure and liquid fertilizer based on results of soil test by each region, nature-recycling form of crops production and livestock production systems by maximizing utilization of different recycling byproducts occurring in the crop producing process by each region.

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Spatial prioritization of permeable pavement considering multiple general circulation models: Mokgamcheon watershed (다수의 전지구모형을 고려한 투수성 포장시설의 우선지역 선정: 목감천 유역)

  • Song, Younghoon;Chung, Eun-Sung
    • Journal of Korea Water Resources Association
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    • v.52 no.12
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    • pp.1011-1023
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    • 2019
  • Rapid urbanization increases the risk of hydrologic disasters due to the increase of impervious areas in urban areas. Precipitation characteristics can be transformed due to the rise of global temperatures. Thus urban areas with the increased impervious areas are more exposed to hydrological disasters than ever before. Therefore, low impact development practices have been widely installed to rehabilitate the distorted hydrologic cycle in the urban area. This study used the Stormwater Management Model to analyze the water quantity and quality of the Mokgamcheon which had been severely urbanized, considering future climate scenarios presented by various general circulation models (GCMs). In addition the effectiveness of permeable pavement by 27 sub-watersheds was simulated in terms of water quantity and quality considering various GCMs and then the priorities of sub-watersheds were derived using an alternative valuation index which uses the pressure-state-response framework.

A Change of Large-scale Circulations in the Indian Ocean and Asia Since 1976/77 and Its Impact on the Rising Surface Temperature in Siberia

  • Lim, Han-Cheol;Jhun, Jong-Ghap;Kwon, Won-Tae;Moon, Byung-Kwon
    • Journal of the Korean earth science society
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    • v.30 no.5
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    • pp.660-670
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    • 2009
  • This study examines the changes of an interdecadal circulation over the Asian continent to find cause of the surface warming in Siberia from 1958 to 2004. According to our study, there is a coherency between a long-term change of sea surface temperature in the Indian Ocean and the rapid increase of air temperature in Siberia since 1976/1977. In this study, we suggest that mean wind field changes induced by the positive sea surface temperature anomalies of the Indian Ocean since 1976/1977 are caused of inter-decadal variations in a large-scale circulation over the Asian continent. It also indicates that the inter-decadal circulation over the Asian continent is accompanied with warm southerly winds near surface, which have significantly contributed to the increase of surface temperature in Siberia. These southerly winds have been one of the most dominant interdecadal variations over the Asian continent since 1976/1977. In addition, we investigated the long-term trend mode of 850 hPa geopotential height data over the Asian continent from the Empirical Orthogonal Function (EOF) analysis for 1958-2004. In result, we found that there was an anomalously high pressure pattern over the Asian continent, it is called 'the Asian High mode'. It is thus suggested that the Asian High mode is another response of interdecadal changes of large-scale circulations over the Asian continent.

Mobility and productivity: brain circulation and sustainability of the Korean academic system

  • Ki-Seok Kwon;Jeongmin Park;Somin Kim
    • Asian Journal of Innovation and Policy
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    • v.12 no.1
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    • pp.27-53
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    • 2023
  • The purpose of this study is to examine the unique characteristics of the Korean academic system with regard to brain circulation, with a specific emphasis on the influence of overseas-trained academics on research activities within the Korean academic system. We have analyzed the statistical data on individual characteristics and performances of 48,499 Korean academics in science and engineering. We have examined the results at both the system and individual levels within the broader context of the macro characteristics of the Korean academic system. Our analysis reveals that the total number of domestically-trained academics exceeds the number of overseas-trained academics. However, in terms of research funding, overseas-trained academics tend to receive more funding than domestically-trained academics. Furthermore, after controlling other factors such as funding, personal attributes, and environmental factors, our analysis demonstrates that overseas training has a significant and favorable impact on the publication of internationally renowned journals. As such, the presence of overseas returnees has been essential for the effective functioning of the Korean academic system in the global research network and for conducting high-quality academic research. Therefore, the advantages of dependence on scientific core countries such as the US for overseas training have persisted. Nevertheless, upon scrutinizing the group of recently appointed 5,806 academics exclusively, we have discovered that junior academics who received their education domestically exhibit sufficient academic proficiency compared to their colleagues educated overseas. This observation highlights the potential for the Korean academic system to evolve into a self-sustaining system.

Interrelationship Study about Pilotis space utilization in high-rise apartment complex and indicator values related with Space Syntax circulation -Focusing on Hwaseong Dongtan Newtown Area Apartment- (고층아파트단지 필로티 공간의 이용도와 공간구문론 동선관련 지표값과의 상관성 연구 -화성동탄신도시아파트를 중심으로-)

  • Song, Byung-Ha;Lee, Ki-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5673-5682
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    • 2015
  • Purpose of this study is to examine and investigate the utilization of low-rise floor Pilotis space which is frequently selected as a major planning element in recent high-rise apartment complex and to identify the interrelationship between the placement of Pilotis space in the complex and space utilization frequency by comparing circulation related indicators of Connectivity, Control Value, Global Integration and Local Integration through Space Syntax axial analysis. Conclusions of this study are, first, Pilotis space is not used as a space to improve regional community consciousness because it is mostly used as a 'simple movement space'. Second, regarding space utilization frequency differences in Pilotis space in each apartment building, projecting entry access+pilotis addition type complex shows more significant utilization frequency than pilotis access type complex, and the vandalism phenomenon is observed more often. Third, Pilotis space utilization is related with Connectivity, Control Value, Global Integration and Local Integration which are circulation related indicators in Space Syntax, and Pilotis spaces with high indicator values over 2 tend to show higher utilization frequency and those with low indicator values over 2 tend to show low utilization frequency.

Analysis of Precipitation Characteristics of Regional Climate Model for Climate Change Impacts on Water Resources (기후변화에 따른 수자원 영향 평가를 위한 Regional Climate Model 강수 계열의 특성 분석)

  • Kwon, Hyun-Han;Kim, Byung-Sik;Kim, Bo-Kyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5B
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    • pp.525-533
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    • 2008
  • Global circulation models (GCMs) have been used to study impact of climate change on water resources for hydrologic models as inputs. Recently, regional circulation models (RCMs) have been used widely for climate change study, but the RCMs have been rarely used in the climate change impacts on water resources in Korea. Therefore, this study is intended to use a set of climate scenarios derived by RegCM3 RCM ($27km{\times}27km$), which is operated by Korea Meteorological Administration. To begin with, the RCM precipitation data surrounding major rainfall stations are extracted to assess validation of the scenarios in terms of reproducing low frequency behavior. A comprehensive comparison between observation and precipitation scenario is performed through statistical analysis, wavelet transform analysis and EOF analysis. Overall analysis confirmed that the precipitation data driven by RegCM3 shows capabilities in simulating hydrological low frequency behavior and reproducing spatio-temporal patterns. However, it is found that spatio-temporal patterns are slightly biased and amplitudes (variances) from the RCMs precipitation tend to be lower than the observations. Therefore, a bias correction scheme to correct the systematic bias needs to be considered in case the RCMs are applied to water resources assessment under climate change.

Precision Evaluation of Recent Global Geopotential Models based on GNSS/Leveling Data on Unified Control Points

  • Lee, Jisun;Kwon, Jay Hyoun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.2
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    • pp.153-163
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    • 2020
  • After launching the GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) which obtains high-frequency gravity signal using a gravity gradiometer, many research institutes are concentrating on the development of GGM (Global Geopotential Model) based on GOCE data and evaluating its precision. The precision of some GGMs was also evaluated in Korea. However, some studies dealt with GGMs constructed based on initial GOCE data or others applied a part of GNSS (Global Navigation Satellite System) / Leveling data on UCPs (Unified Control Points) for the precision evaluation. Now, GGMs which have a higher degree than EGM2008 (Earth Gravitational Model 2008) are available and UCPs were fully established at the end of 2019. Thus, EIGEN-6C4 (European Improved Gravity Field of the Earth by New techniques - 6C4), GECO (GOCE and EGM2008 Combined model), XGM2016 (Experimental Gravity Field Model 2016), SGG-UGM-1, XGM2019e_2159 were collected with EGM2008, and their precisions were assessed based on the GNSS/Leveling data on UCPs. Among GGMs, it was found that XGM2019e_2159 showed the minimum difference compared to a total of 5,313 points of GNSS/Leveling data. It is about a 1.5cm and 0.6cm level of improvement compare to EGM2008 and EIGEN-6C4. Especially, the local biases in the northern part of Gyeonggi-do, Jeju island shown in the EGM2008 was removed, so that both mean and standard deviation of the difference of XGM2019e_2159 to the GNSS/Leveling are homogeneous regardless of region (mountainous or plain area). NGA (National Geospatial-Intelligence Agency) is currently in progress in developing EGM2020 and XGM2019e_2159 is the experimentally published model of EGM2020. Therefore, it is expected that the improved GGM will be available shortly so that it is necessary to verify the precision of new GGMs consistently.