• Title/Summary/Keyword: Surface Temperature Variation

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The Response of the Subtropical High to the Variation of the Earth Surface Temperature (지구표면 온도의 변화에 대한 아열대 고기압의 반응)

  • 이재규
    • Journal of Environmental Science International
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    • v.7 no.5
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    • pp.725-733
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    • 1998
  • Three numerical experiments are done using IAP(Institute of Atmospheric Physics) global spectral model(T42L9) to investigate the influence of the surface temperatures on the 7-day simulation. Particularly, the response of the subtropical High in summer to the variation of soil temperature and sea surface temperature(SST) was emphasized through a series of experiments. Experiment 1 uses the June climate data as the earth surface conditions. Experiment 2 is similar to Experiment 1 except for the soil surface temperature. Experiment 3 is the same as Experiment 1 except for the modified SST, which is much warmer than the June climate SST on the sea around the Korean peninsula. The main finding in 7-day simulation is that the response of the subtropical high in summer to the variation of the sell surface temperature was much more than that to the variation of the SST. It is implied that the proper treatment of sell surface temperature is more important than that of the SST for the better 7-day simulation of the subtropical high in summer.

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Relationship between Sea Surface Temperature and Air Temperature Variation Depend on Time Scale at Coastal Stations in Korea (시간스케일에 따른 해양표면수온과 기온의 변동 및 상관연구)

  • 장이현;강용균;서영상
    • Journal of Environmental Science International
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    • v.9 no.4
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    • pp.303-309
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    • 2000
  • The relationship between air temperature and sea surface temperature and studied using the daily air temperature and sea surface temperature data for 25 years (1970~1994) at 9 coastal stations in Korea. Seasonal variations of air temperature have larger amplitudes than those of sea surface temperature. The seasonal variations of air temperature leads those of sea surface temperature by 2 to 3 weeks. The anomalies of sea surface temperature and air temperature with time scales more than 1 month are more ghighly correlated than those of short term, with time scales less than 1 month. Accumulated monthly anomalies of sea surface temperature and air temperature for 6 months shwoed higher correlation than the anomailes of each month. The magnitudes of sea surface temperature and air temperature anomalies are related with the duration of anomalies. Their magnitudes are large when the durations of anomalies are long.

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Secular Variations of Surface Water Temperature in Youngil Bay (영일만 해역 표면수온의 누년변화)

  • 양삼승
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.21 no.1
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    • pp.62-66
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    • 1985
  • The periodic variations of the surface water temperature and the relationships between the surface water and air temperature are found in Youngil bay as follows: It is considered that the average surface water temperature is the lowest in February and the highest in August in the Youngil bay (Pohang bay and Janggi cape) from January, 1962 to December, 1981. It is only in October and November that the average surface water temperature was higher in pohang bay than in the Janggi cape from January, 1962 to December, 1981. Since the periodic secular variation in the vincity of Youngil bay and the variation of the Tsushima Current seem to have similar tendencies, we may conclude that the changes of the surface water temperature in Youngil bay are primarily influenced by the Taushima Current. The average temperature of surface water is 14.5$^{\circ}C$ in Pohang bay and 15.$0^{\circ}C$ in Janggi cape in the secular variation.

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Field Test of Tunnel Lining Temperature Variation Using Insulation Material (단열재를 활용한 터널라이닝 온도변화 현장 실험)

  • Jin, Hyunwoo;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.4
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    • pp.11-16
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    • 2019
  • The low temperature and temperature difference (variation) may cause to deteriorate the integrity of tunnel constructed in cold region. An insulation material was developed and applied to the tunnel lining surface to keep the temperature of tunnel lining constant in spite of temperature variation at outdoor. The lining surface where the insulation material applied showed the less sensitive to temperature variation than non-applied lining surface.

Anomalous Variation of the Oceanic Features around Korean Waters Related to the Global Change (지구환경 변화와 관련된 한국 연근해 해양 이상변동)

  • 서영상;장이현;황재동
    • Journal of Environmental Science International
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    • v.12 no.3
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    • pp.257-263
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    • 2003
  • Oceanographic features around Korean waters related to the global change were studied by analysis of the longterm variation of water temperature, dissolved oxygen, sea level of the surface layer with 1$^{\circ}C$ temperature, spatial position of the subpolar front in the East Sea/Japan Sea (the East sea hereafter) and the Wolf Sunspot Number. With the global warming, the temperature of Korean waters has been increased 0.5∼1.0$^{\circ}C$ for 33years (1968∼2000). In case of the dissolved oxygen in the East Sea has been decreased 0.46$m\ell$/$\ell$. Year to year vertical fluctuations of the monthly anomalies of the surface layer with 1$^{\circ}C$water in the East Sea have predominant periods with 15years as the longterm variation of Arctic climate, 12 and 18years as the El Nino-Southern Oscillation. Spatial position of the subpolar front in the East Sea moved to northern part of the sea from the southern part of the sea with the increasing sea surface temperature. The relationship between the number of Wolf Sunspot and the anomalies of sea surface temperature was very closer after the late of 1980s than those before the early of 1980s in Korean waters.

A Study on the Behavior of Buffer Layer in Turbulent Boundary Layer with Variation of Surface Temperature and Roughness (표면온도 및 조도분포가 있는 경우 난류경계층의 완충층 거동에 관한 연구)

  • 정동빈
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.1
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    • pp.83-92
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    • 1999
  • In this paper, the wind tunnel test was carried to investigate the behavior of buffer layer in turbulent boundary layer with variation of surface temperature and roughness. The results were as follows; 1. The velocity in turbulent boundary layer was increased when the roughness height within viscous sublayer thickness was increased. 2. When the surface temperature was increased, the density of air was decreased and the velocity in turbulent boundary layer was increased. Thus, the thickness of turbulent boundary layer was decreased. 3. When the roughness height and surface temperature was increased simultaneously, the thickness of turbulent boundary layer was decreased. 4. The decrement of the thickness of turbulent boundary layer was more effected by the increment of the roughness height rather than the increment of surface temperature. 5. In this study, it was found that the condition of the highest velocity n turbulent boundary layer was the temperature 333K and roughness #100.

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Compensation of Skin Surface Temperature Variation on the PPG for the U-Healthcare System (U-Healthcare시스템을 위한 PPG의 피부표면의 온도변화보상)

  • Yeom, Ho-Jun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.6
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    • pp.319-324
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    • 2011
  • This study aims to investigate statistical variations and relationships of blood pressure (BP), phtotplethysmography (PPG) and cardiovascular parameters on changes in local skin surface temperature (SST) during gradual cooling and heating. Results showed that local SST changes affected the Finometer BP, the PPG waveforms and total peripheral resistance, but not oscillometric BP, heart rate, stroke volume and cardiac output. Therefore, in order to reduce for the errors, temperatures should be controlled or compensated when components of the PPG waveform are used to evaluate cardiovascular status in temperature variation environments.

Analysis of unsteady temperature distribution in a cylinder for rifle barrel disign (원통형 용기의 비정상온도해석)

  • ;;;Lee, Hung Joo
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.3 no.4
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    • pp.173-180
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    • 1979
  • Temperature distriburion in a hollow chlinder has been analyzed mathematically. Unsteady condition considered assumed a constant heat flux input from the inside. The results are compared with experimental results of surface temperature rise of a gun barrel during continuous firing. Their agreements are acceptable. Effects of various dimensionless parameters on the surface temperature rise are discussed. For small Biot numbers, the external survface temperature approaches more rapidly to the steady temperature. Temperature difference between internal and external surfaces becomes greater for small Biot number. Steady solution assumed that the gas temperature inside the cylinder varies periodically. Relative amplitude and phase angles between the gas temperature and the internal or external surface temperature are obtained. Phase angles become smaller for large radiancy of gas temperature variation, small external Biot number, or large internal biot number. Relative amplitudes become samller as radiancy of gas temperature variation and internal Biot number become smaller. or external Biot number becomes larger. The solution obtained in this paper can be applied to gun barrels, heat pipes used in heat excangers, and reciprocation engines.

Long-term Variability of Sea Surface Temperature in the East China Sea: A Review (동중국해 표층수온의 장기 변동성: 종설)

  • Lee, Jae Hak;Kim, Cheol-Ho
    • Ocean and Polar Research
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    • v.35 no.2
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    • pp.171-179
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    • 2013
  • The long-term variability of sea surface temperature in the East China Sea was reviewed based mainly on published literatures. Though the quantitative results are not the same, it is generally shown that sea surface temperature is increasing especially in recent years with the rate of increase about $0.03^{\circ}C$/year. Other meaningful results presented in the literatures is that the difference of water properties between layers upper and lower than the thermocline in summer shows an increasing trend both in temperature and salinity, suggesting that the stratification has been intensified. As a mechanism by which to evaluate the wintertime warming trend in the region, the weakening of wind strength, which is related to the variation of sea level pressure and atmospheric circulation in the western North Pacific and northern Asian continent, is suggested in the most of related studies.

A Study on the Analysis of Surface Heat Flux Using the Transient Heat Flux Method (비정상열유속 기법을 이용한 표면 열유속 해석에 관한 연구)

  • Yi, Jong-Ju
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.3
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    • pp.503-510
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    • 2010
  • The quick variation of the canister wall temperature causes the modification of the shape of canister wall. This paper is the possibility of adoption and the error analysis about the transient heat flux method. The commercial code(Fluent Ver6.2.16) was employed for the calculation of surface temperature in the case of steady and unsteady heat flux condition. Based the surface temperature variation and surface material property, transient heat flux method can calculate the surface heat flux. In the case of steady heat flux condition, the error is about 2%, and in the case of unsteady heat flux condition, the error is about 3.6%. With the unsteady heat flux condition, the time which reach the maximum surface heat flux is almost same between the numerical analysis and transient heat flux method.