• 제목/요약/키워드: Heat budget

검색결과 103건 처리시간 0.028초

An Observational Study on the Differences in Thermal Characteristics of the Upo Wetland and Converted Areas from Wetland to Paddy Field

  • Koo, Hyun-Suk;Jeon, Dae-Youn;Kim, Hae-Dong
    • 한국지구과학회지
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    • 제30권5호
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    • pp.622-629
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    • 2009
  • This study intended to collect data for evaluating the meteorological value of Upo Wetland which is the largest wetland in the downstream of Nakdong River. The observations were conducted in summer at the Upo Wetland and its surrounding paddy field that is the converted areas from a wetland to a paddy field. The following results are obtained: 1) The temperature of Upo Wetland area was $1^{\circ}C$ lower than the surrounding area during the day while it was a little higher during the night.; 2) The maximum wind speed in the Upo Wetland area was 3.5 m/s which is stronger than 1.6 m/s of its surrounding area. The south wind was observed in the farmland for most of the day while north winds and south winds alternated between day and night in Upo Wetland.; 3) In heat budget analysis, Upo Wetland was wasted in the form of latent heat rather than sensible heat in daytime.

육상지형을 고려한 연안해역에서의 중규모 기상장과 취송류에 관한 수치해석 (Numerical Analysis of Wind Driven Current and Mesoscale Air Flow in Coastal Region with Land Topography)

  • 이성대
    • 한국해양공학회지
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    • 제20권5호
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    • pp.23-29
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    • 2006
  • A quasi depth-varying mathematical model for wind-generated circulation in coastal areas, expressed in terms of the depth-averaged horizontal velocity components and free surface elevation was validated and used to understand the diurnal circulation process. The wind velocity is considered as a dominant factor for driving the current. In this paper, three-dimensional numerical experiments that included the land topography were used to investigate the mesoscale air flaw over the coastal regions. The surface temperature of the inland area was determined through a surface heat budget consideration with the inclusion of a layer of vegetation.A series of numerical experiments were then carried out to investigate the diurnal response of the air flaw and wind-generated circulation to various types of surface inhomogeneities.

Improvement of Boron Penetration and Reverse Short Channel Effect in 130nm W/WNx/Poly-Si Dual Gate PMOSEET for High Performance Embedded DRAM

  • Cho, In-Wook;Lee, Jae-Sun;Kwack, Kae-Dal
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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    • pp.193-196
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    • 2002
  • This paper presents the improvement of the boron penetration and the reverse short channel effect (RSCE) in the 130nm W/WNx/Poly-Si dual gate PMOSFET for a high performance embedded DRAM. In order to suppress the boron penetration, we studied a range in the process heat budget. It has shown that the process heat budget reduction results in suppression of the boron penetration. To suppress the RSCE, we experimented with the halo (large tilt implantation of the same type of impurities as those in the device well) implant condition near the source/drain. It has shown that the low angle of the halo implant results in the suppression of the RSCE. The experiment was supported from two-dimensional(2-D) simulation, TSUPREM4 and MEDICI.

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해안 대기 표층의 난류와 해안 대기 경계층의 구조 (Turbulence of the Coastal Atmospheric Surface Layer and Structure of the Coastal Atmospheric Boundary Layer)

  • 권병혁
    • 수산해양교육연구
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    • 제17권3호
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    • pp.404-412
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    • 2005
  • The surface energy budget depends on many factors, such as the type of surface, the soil moisture and the vegetation canopy, the geographical location, daily, monthly and seasonal variations, and weather conditions. In the coastal region, the surface is not homogeneous at various scales for instance water, sand, mud, tall grass, and crops. The energy balance over the vegetation canopy was analyzed with the optical energy balance measuring system. The latent heat flux was more intensive than the sensible heat flux. The sensible heat flux was very small in summer due to the canopy effect and higher in spring and autumn. In summer the development of the atmospheric boundary depended on rather the vertical shear of wind than the sensible heat flux.

경량모듈형 옥상녹화시스템의 온도저감 및 열수지 평가 (Assessment of Temperature Reduction and Heat Budget of Extensive Modular Green Roof System)

  • 김세창;박봉주
    • 원예과학기술지
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    • 제31권4호
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    • pp.503-511
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    • 2013
  • 본 연구는 돌나물과 한국잔디를 식재한 경량 모듈형 옥상녹화시스템의 온도저감과 열수지를 평가하였다. 식물생육은 초고와 피복율을 측정하였으며, 2012년 8월 2일부터 3일까지 48시간 동안 콘크리트와 옥상녹화 표면, 토양 속, 모듈 하부의 온도와 순복사, 증발산량을 측정하였다. 기온이 $34.6^{\circ}C$로 가장 높았던 8월 3일 15:00시의 표면온도는 콘크리트가 $57.5^{\circ}C$로 가장 높았으며, 그 다음으로 돌나물 $40.1^{\circ}C$, 한국잔디 $38.3^{\circ}C$의 순으로 옥상녹화 조성 시 큰 폭으로 온도가 저감되는 것으로 나타났다. 토양 속과 모듈 하부도 옥상녹화에 의한 온도저감 효과가 나타났으며, 한국잔디가 돌나물보다 온도저감 효과가 큰 것으로 나타났다. 콘크리트 표면과 비교하여 옥상녹화 최고 온도는 약 2시간 정도 지연되는 것으로 나타났다. 표면의 온도저감에는 식물종, 기온, 토양수분이 영향을 미치고, 모듈 하부의 온도저감에는 식물종, 기온, 토양수분, 표면온도가 유의하게 영향을 미친 것으로 나타났다. 열수지 분석결과, 현열은 콘크리트 표면이 가장 높았으며, 옥상녹화 시 감소하는 경향을 보였으며 잠열은 한국잔디가 돌나물보다 높았다. 따라서 온열환경 개선을 위해서는 한국잔디가 돌나물보다 옥상녹화 적용에 더 효과적임을 알 수 있었다.

Estimated Advection Heat in the East/Japan Sea

  • Han, In-Seong;Kang, Yong-Q;Kim, Bok-Kee;Seong, Ki-Tack
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 2003년도 International Symposium on Clean Environment
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    • pp.165-170
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    • 2003
  • A significant surface net heat loss appears around the Kuroshio and the Tsushima Warm Current regions. The area where the surface heat loss occurs should require heat to be supplied by the current to maintain the long-term annual heat balance. Oceanic heat advection in these regions plays an important role in the heat budget. The spatial distribution of the heat supply by the Tsushima Warm Current near the surface was examined by calculating the horizontal heat supply in the surface layer of the East/Japan Sea, directly from historical sea surface temperature and current data. We have also found a simple estimation of the effective vertical scale of heat supply by the current to compensate net heat loss using the heat supplied by the current in the surface 10m layer. The heat supplied by the current for the annual heat balance was large in the Korea/Tsushima Strait and along the Japanese Coast, and was small in the northwestern part of the East/Japan Sea. The amount of heat supplied by the current was large in the northwestern part and small in the southeastern part of the East/Japan Sea. These features suggest that the heat supplied by the Tsushima Warm Current is restricted to near the surface around the northeastern part and extends to a deeper layer around the southeastern part of the East/Japan Sea.

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낙동강 강정고령보의 여름철 열수지 일변화 - 열 저장량 변동을 중심으로 - (Daily Variation of Heat Budget Balance in the Gangjeong-Goryung Reservoir for Summertime - Concerning around the Rate of Heat Storage -)

  • 김성락;조창범;김해동
    • 한국환경과학회지
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    • 제24권6호
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    • pp.721-729
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    • 2015
  • Surface heat balance of the Gangjeong-Goryung Reservoir is analyzed for 12-17 August 2013. Each flux elements at the water surface is derived from the special field observations with application of an aerodynamical bulk method for the turbulent heat fluxes and empirical formulae for the radiation heat fluxes. The rate of heat storage in the reservoir is estimated by using estimated by surface heating rate and the vertical water temperature data. The flux divergence of heat transport is estimated as a residual. The features of the surface heat balance are almost decided by the latent heat flux and the solar radiation flux. On average for 12-17 August 2014 in the Gangjeong- Goryung Reservoir, if one defines the insolation at the water surface as 100 %, 94 % is absorbed in the reservoir; thereafter the reservoir loses about 30~50% by sensible heat, latent heat and net long-wave radiation. The residue of 50~80 % raises the water temperature in the reservoir or transported away by the river flow during the daytime.

한반도 2007년 여름철 인지온도 특성 연구 (A Study on the Characteristics of Perceived Temperature over the Korean Peninsula During 2007 Summer)

  • 변재영;김정식;김지영;최병철;최영진
    • 대기
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    • 제18권2호
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    • pp.137-146
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    • 2008
  • This study examines one thermal index, perceived temperature (PT), over the Korean Peninsula during 2007 summer. Heat/cold stress has been described using air temperature and humidity for warm seasons and air temperature and wind velocity in the cold conditions, while PT is based on a heat budget model of the human body that considers air temperature, humidity, wind velocity and radiation effect regardless of climates, regions and seasons. PT is higher about $4-5^{\circ}C$ than air temperature in the summer. Humidity increases PT, while wind tends to reduces PT possibly by evaporation of water vapor. The geographical distribution of summer PT indicates that the lowest PT happened in the east central region, with the appearance of the highest PT in the inland of southern region in Korea. Although the latitudinal trend shows that PT decreases northward, inland PT is higher than that of coastal region. Compared to the heat index or the discomfort index that considers air temperature and humidity, PT represents distinctive regional characteristics of thermal comfort. The distribution of PT shows that it may be a useful thermal index for the assessment of thermal comfort or stress region in the Korean Peninsula.

EVALUATION OF SURFACE HEAT FLUXES FOR DIFFERENT LAND COVER IN HEAT ISLAND EFFECT

  • Chang, Tzu-Yin;Liao, Lu-Wei;Liou, Yuei-An
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.68-71
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    • 2008
  • Our goal is to obtain a better scientific understanding how to define the nature and role of remotely sensed land surface parameters and energy fluxes in the heat island phenomena, and local and regional weather and climate. By using the MODIS visible and thermal imagery data and analyzing the surface energy flux images associated with the change of the landcover and landuse in study area, we will estimate and present how significant is the magnitude of the heat island heat effect and its relation with the surface parameters and the energy fluxes in Taiwan. To achieve our objective, we used the energy budget components such as net radiation, soil heat flux, sensible heat flux, and latent heat flux in the study area of interest derived form remotely sensed data to understand the island heat effect. The result shows that the water is the most important component to decrease the temperature, and the more the consumed net radiation to latent heat, the lower urban surface temperature.

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Surface Heat Flux and Oceanic Heat Advection in Sendai Bay

  • Yang Chan-Su;Hanawa Kimio
    • 대한원격탐사학회지
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    • 제22권1호
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    • pp.11-24
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    • 2006
  • Coastal sea surface temperature (CSST) and meteorological data from January through December 1995 are used to estimate the net surface heat flux and heat content for Sendai Bay. The average annual surface heat flux in the area north of the bay is estimated to be $+35Wm^{-2}$, whereas the southwestern area is estimated to be $+56Wm^{-2}$. Therefore, the net surface heat flux shows a net gain of heat over the whole bay. The largest heat gain occurs near Matsukawaura, where the strong Kuroshio/Oyashio interaction produces anomalously cold SST and wind is more moderate than in other regions of Sendai Bay over most of the year. The lowest heat gain occurs around Tashiro Island, where the temperature difference between air and sea surface is lower and wind is stronger. The heat budget shows that both surface forcing and horizontal advection are potentially important contributors to the seasonal evolution of CSST in the bay. From the A VHRR and SeaWiFS data, it is found that offshore conditions between the bay and Eno Island are different due to the presence of the Ojika Peninsula. It is also shown that the temporal behaviors of SSTs in the bay are closely connected with the air-sea heat flux and offshore conditions.