• Title/Summary/Keyword: Wind climate

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The Characteristics of Earth System Thinking of Science Gifted Students in relation to Climate Changes (기후변화와 관련된 과학영재들의 지구시스템 사고 특성)

  • Park, Kyeong-Jin;Chung, Duk-Ho
    • Journal of Gifted/Talented Education
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    • v.24 no.2
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    • pp.271-288
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    • 2014
  • This study aimed to investigate the perception of earth system thinking of science gifted students in future problem solving (FPS) in relation to climate changes. In order to this study, the research problem associated with climate changes was developed through a literature review. The thirty seven science gifted students participated in lessons. The ideas in problem solving process of science gifted students were analyzed using the semantic network analysis method. The results are as follows. In the problem solving processes, science gifted students are 'changes of the sunlight by water layer', 'changes of the Earth's temperature', 'changes of the air pressure', ' change of the wind and weather' were represented in order. On other hand, regard to earth system thinking for climate changes, while science gifted students were used sub components related to atmospheres frequently, they were used sub components related to biosphere, geosphere, and hydrosphere a little. But, the analytical results of the structural relationship between the sub components related to earth system, they were recognised that biosphere, geosphere, and hydrosphere used very important in network structures. In conclusion, science gifted students were understood well that components of the earth system are influencing each other.

Topographic and Meteorological Characteristics of Pinus densiflora Dieback Areas in Sogwang-Ri, Uljin (울진 소광리 산림유전자원보호구역 내 금강소나무 고사지역의 지형 환경 특성 분석)

  • Kim, Jaebeom;Kim, Eun-Sook;Lim, Jong-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.1
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    • pp.10-18
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    • 2017
  • Korean Red Pine (Pinus densiflora) has been protected and used as the most ecologically and socio-culturally important tree species in Korea. However, as dieback of Korean red pines has occurred in the protected area of the forest genetic resources. The aims of this study is to identify causes for dieback of pine tree by investigating topographical characteristics of pine tree dieback and its correlation to meteorological factors. We extracted the dead trees from the time series aerial images and analyzed geomorphological characteristics of dead tree concentration area. As a result, 1,956 dead pine trees were extracted in the study region of 2,600 ha. Dieback of pine trees was found mostly in the areas with high altitude, high solar radiation, low topographic wetness index, south and south-west slopes, ridgelines, and high wind exposure compared to other living pine forest area. These areas are classified as high temperature and high drought stress regions due to micro-climatic characteristics affected by topographic factors. As high temperature and drought stress are generally increasing with climate change, we can evaluated that a risk of pine tree dieback is also increasing. Based on these geomorphological characteristics, we developed a pine tree dieback risk map using Maximum Entropy Model (MaxEnt), and it can be useful for establishing Korean red pine protection and management strategies.

Characteristics of Air Stagnation over the Korean Peninsula and Projection Using Regional Climate Model of HadGEM3-RA (한반도 대기정체의 특성 및 지역기후모델 HadGEM3-RA를 이용한 미래 전망)

  • Kim, Do-Hyun;Kim, Jin-Uk;Kim, Tae-Jun;Byon, Jae-Young;Kim, Jin-Won;Kwon, Sang-Hoon;Kim, Yeon-Hee
    • Atmosphere
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    • v.30 no.4
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    • pp.377-390
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    • 2020
  • Not only emissions, but also atmospheric circulation is a key factor that affects local particulate matters (PM) concentrations in Korea through ventilation effects and transboundary transports. As part of the atmospheric circulation, air stagnation especially adversely affects local air quality due to weak ventilation. This study investigates the large-scale circulation related to air stagnation over Korea during winter and projects the climate change impacts on atmospheric patterns, using observed PM data, reanalysis and regional climate projections from HadGEM3-RA with Modified Korea Particulate matter Index. Results show that the stagnation affects the PM concentration, accompanied by pressure ridge at upper troposphere and weaken zonal pressure gradient at lower troposphere. Downscaling using HadGEM3-RA is found to yield Added-Value in the simulated low tropospheric winds. For projection of future stagnation, SSP5-8.5 and SSP1-2.6 (high and low emission) scenarios are used here. It has been found that the stagnation condition occurs more frequently by 11% under SSP5-8.5 and by 5% under SSP1-2.6 than in present-day climate and is most affected by changes in surface wind speed. The increase in the stagnation conditions is related to anticyclonic circulation anomaly at upper troposphere and weaken meridional pressure gradient at lower troposphere. Considering that the present East Asian winter monsoon is mainly affected by change in zonal pressure gradient, it is worth paying attention to this change in the meridional gradient. Our results suggest that future warming condition increase the frequency of air stagnation over Korea during winter with response of atmospheric circulation and its nonlinearity.

Evaluation of the Radiant Heat Effects according to the Change of Wind Velocity in Forest Fire by using WFDS (WFDS를 이용한 풍속에 따른 산림화재 복사열 강도 평가)

  • Song, Dong-Woo;Lee, Su-Kyung
    • Fire Science and Engineering
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    • v.27 no.3
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    • pp.1-7
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    • 2013
  • The wildland fire intensity and scale are getting bigger owing to climate change in the world. In the case of domestic, the forest is distributed over approximately 63.7 % of country and the main facilities like a industrial facility or gas facility abuts onto it. Therefore there is potential that the wildland fire is developed to a large-scale disaster. In this study, the effect distances of the radiant heat flux from the crown fire are analysed according to the change of wind velocity. The safety criteria concerning the radiant heat flux to influence on the surrounding were researched to analyse the effect distances. The criteria of radiant heat flux were chosen $5kW/m^2$, $12.5kW/m^2$, $37.5kW/m^2$. WFDS, which is an extension of NIST's Fire Dynamics Simulator, was used to consequence analysis of the forest fire. In order to apply the analysis conditions, it is researched the forest conditions that is generally distributed in domestic region. As the result, the maximum effect distances by radiant heat were showed at the horizontal and vertical direction. When the wind velocity varied from 0 to 10 m/s, the maximum effect distance increased as the wind velocity increases. Interesting point is that the maximum effect distance were shown at the wind velocity of 8 m/s. The maximum effect distance was decreased according as the fuel moisture of trees increase. This study can contribute to analyse quantitative risk about the damage effect of the surrounding facilities caused by wildland fire.

Spatial Distribution Patterns of Winter Daytime and Nighttime Apparent Temperature in South Korea (남한의 겨울철 주.야간 체감 온도의 공간적 분포 특성)

  • 최광용;강철성
    • Journal of the Korean Geographical Society
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    • v.37 no.3
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    • pp.237-246
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    • 2002
  • This study classified wintertime bioclimatic zones of South Korea based on daytime and nighttime distribution of wind chill index calculated from climate data during the coldest month for latest 30 years (1971- 2000). The results show that the winter daytime and nighttime wind chill index were influenced by climatic factors such as elevation, land-sea breeze, topology, and sea currents etc. as well as climatic components such as temperature, wind speed, and sunshine, so that South Korea was divided into five bioclimatic zones; Cool day- cold night zone, Keen day- Cold night zone, Keen day-Very Cold night zone, Cold day and night zone, and Cold day-Extremely Cold night zone. Especially, coasts and island areas, except for south coast of Korea, shows Keen bioclimatic response during daytime and Very Cold bioclimatic response during nighttime. This indicates that coasts and island areas, except for south coast of Korea are affected by moonson and land-sea breeze. In addition, highly elevated Daegwallyeong shows Cold bioclimatic response during daytime and Extremely Cold during nighttime due to the influence of adiabatic temperature lapse rate and monsoon. This study offers basic data necessary to make decisions concerning insulation such as clothing and architect etc. by classifying winter bioclimatic zones of South Korea based on various daytime and nighttime distribution of wind chill.

A Study on the Calculation of Total Design Water Depth From Typhoon Waves (태풍파를 기준으로한 전설계수심의 산정에 관한 연구)

  • 이종우
    • Journal of the Korean Institute of Navigation
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    • v.13 no.3
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    • pp.45-65
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    • 1989
  • Various typhoon data near Yongil Bay, Korea from 1961 to 1985 were collected with some critria and analyzed with the help of the computer. Introducing the pressure profile models and predicting the typhoon wind and wave fields, the 100-year design wave parameters were calculated. Additionally, the wave data at the southeast coast of Korea were statistically analyzed. The deep water wave climate of this bay indicated that Typhoon Brenda, 1985 had wave characteristics of 100-year return period, Typhoon model and storm surge model studies were made for this typhoon. These, including other design parameters, were introduced into the calculation of total design water depth.

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Contamination and Climate Properly Analysis of Outdoor Insulator by DB Model (DB 분석을 통한 옥외 절연물의 오손 및 기후특성 분석)

  • Kim, Do-Young;Kim, Jae-Hoon;Lee, Won-Young;Park, Doo-Ki;Han, Sang-Ok;Park, Kang-Sik
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1832-1834
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    • 2004
  • The degree of contamination on outdoor insulator is one of the most importance factors to determine the pollution level of outdoor insulations, and the sea salt is known as the most dangerous pollutant. As shown through the preceding study, the generation of salt pollutant and the pollution degree of outdoor insulator have a close relation with meteorological conditions, such as wind velocity, rainfall, and so on. So, in this paper, we have made database using the past meteorological data and ESDD(equivalent salt deposit density) and then we predicted the pollution degree in the future after analyzing currently meteorological data of database.

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The Relationship between Climatic and Oceanographic Factors and Laver Aquaculture Production (기후 및 해양 요인과 김 생산량과의 관계에 관한 연구)

  • Kim, Do-Hoon
    • The Journal of Fisheries Business Administration
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    • v.44 no.3
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    • pp.77-84
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    • 2013
  • While some steps in laver aquaculture production can be controlled artificially to a certain extent, the culturing process is largely affected by natural factors, such as the characteristics of seawater, climatic and oceanographic conditions, etc. This study aims to find a direct relationship between climatic and oceanographic factors (water temperature, air temperature, salinity, rainfall, sunshine duration and wind speed) and laver aquaculture production in Wando region, the biggest aquaculture production area of laver, located in the southwest coast of Korea using a multiple regression analysis. Despite the small sample size of a dependent variable, the goodness of model fit appeared acceptable. In addition, the R-squared value was 0.951, which means that the variables were very explanatory. Model results indicated that duration of sunshine, temperature, and rainfall during the farming period from the end of September to the end of April would be important factors affecting significantly to the laver aquaculture production.

Economical design for power transmission steel towers (경제적인 송배전철탑설계)

  • 이재숙
    • 전기의세계
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    • v.16 no.5
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    • pp.37-50
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    • 1967
  • The economical design of steel towers fortrausmission line. This study has been made on the design criteria of steel towers for power trasmission line adopted in the United States of America, France, Japan and Korea in order to find out any access to design the economical steel twers in Korea following to our own climate conditions. As the result of this study, involved in this description. Writer belive that the weight of steel towers can be saved by 10% to 20% approximately on the steel towers which will be constructed in the near future in Korea, by the possibility of reducing the design wind pressures on towers and cables in those areas of inland of Korea, the increase of number of standard towers from four types to five, the adoption of comparative narrower base towers than those in past practice and improvement on the assumption of manimum delection angle of suopension type insulator strings.

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STOCHASTIC SIMULATION OF DAILY WEATHER VARIABLES

  • Lee, Ju-Young;Kelly brumbelow, Kelly-Brumbelow
    • Water Engineering Research
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    • v.4 no.3
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    • pp.111-126
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    • 2003
  • Meteorological data are often needed to evaluate the long-term effects of proposed hydrologic changes. The evaluation is frequently undertaken using deterministic mathematical models that require daily weather data as input including precipitation amount, maximum and minimum temperature, relative humidity, solar radiation and wind speed. Stochastic generation of the required weather data offers alternative to the use of observed weather records. The precipitation is modeled by a Markov Chain-exponential model. The other variables are generated by multivariate model with means and standard deviations of the variables conditioned on the wet or dry status of the day as determined by the precipitation model. Ultimately, the objective of this paper is to compare Richardson's model and the improved weather generation model in their ability to provide daily weather data for the crop model to study potential impacts of climate change on the irrigation needs and crop yield. However this paper does not refer to the improved weather generation model and the crop model. The new weather generation model improved will be introduced in the Journal of KWRA.

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