• Title/Summary/Keyword: surface fluxes

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Mixed Layer Variability in Northern Arabian Sea as Detected by an Argo Float

  • Bhaskar, T.V.S. Udaya;Swain, D.;Ravichandran, M.
    • Ocean Science Journal
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    • v.42 no.4
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    • pp.241-246
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    • 2007
  • Northern Arabian Sea (NAS) between $17^{\circ}N-20.5^{\circ}N$ and $59^{\circ}E-69^{\circ}E$ was observed by using Argo float daily data fur about 9 months, from April 2002 through December 2002. Results showed that during April - May mixed layer shoaled due to light winds, clear sky and intense solar insolation. Sea surface temperature (SST) rose by $2.3^{\circ}C$ and ocean gained an average of 99.8 $Wm^{-2}$. Mixed layer reached maximum depth of about 71 m during June - September owing to strong winds and cloudy skies. Ocean gained abnormally low $\sim18Wm^{-2}$ and SST dropped by $3.4^{\circ}C$. During the inter monsoon period, October, mixed layer shoaled and maintained a depth of 20 to 30 m. November - December was accompanied by moderate winds, dropping of SST by $1.5^{\circ}C$ and ocean lost an average of 52.5 $Wm^{-2}$. Mixed layer deepened gradually reaching a maximum of 62 m in December. Analysis of surface fluxes and winds suggested that winds and fluxes are the dominating factors causing deepening of mixed layer during summer and winter monsoon periods respectively. Relatively big]h correlation between MLD, net heat flux and wind speed revealed that short term variability of MLD coincided well with short term variability of surface forcing.

Atmospheric Dry Deposition Characteristics of Nitrogen-containing Compounds into Juam Reservoir (주암호에 대한 질소화합물의 대기건식침적 특성)

  • Cheong Jang-Pyo;Jang Young-Hoan
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.6
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    • pp.657-666
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    • 2005
  • The objectives of this study were to investigate atmospheric dry deposition of inorganic nitrogen-containing compounds to waterbody. Target waterbody is Juam reservoir functioning as one of the major water supply sources in Chollanamdo. Nitrate and ammonium dry deposition fluxes were directly measured using dry deposition plate (DDP) covered with greased strips and a water surface sampler (WSS). The daytime average $NO_{3}^{-}\;and\;NH_{4}^{+}$ fluxes measured with DDP and WSS were $1.7\∼2.6$ times higher than those at nighttime. The seasonal average flux of $NH_{4}^{+}$ showed the highest value in summer. The daytime and nighttime average dry deposition fluxes of particulate phase Nitogen-containing Compounds ($1.13,\;0.80\;mg/m^{2}$ day) were much higher than those of gas phase compounds ($0.50,\;0.24\;mg/m^{2}$ day).

Evaporation of Water in an Aqueous Lithium Bromide Solution flowing over a Horizontal Tube

  • Kim, Dong-Kwan;Kim, Moo-Hwan
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.3
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    • pp.57-62
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    • 2001
  • Falling film heat transfer analyses with aqueous lithium bromide solution were performed to investigate the transfer characteristics of the copper tubes. Finned (knurled) tube and a smooth tube were selected as test specimens. Averaged generation fluxes of water and the heat flux were obtained. As the film flow rate of the solution increased, the generation fluxes of water decreased for both tubes due to the fact that the heat transfer resistance increased with the film thickness. The effect of the enlarged surface area at the knurled tube was supposed to be dominant at a small flow rate. The generation fluxes of water increased with the increasing degree of tube wall superheat. Nucleate boiling is supposed to occur at a wall superheat of 20K for a smooth tube, and at 10K for a knurled tube. The increased performance of the knurled tube was supposed to mainly come from the effect of the increased heating surface area.

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On the Thermal Effect of Vegetation Canopy to the Surface Sublayer Environment Part 1 : Numerical Experiment (Vegetation Canopy의 접지층 환경에 대한 열적 영향 제1부 : 수치실험)

  • 진병화;황수진
    • Journal of Environmental Science International
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    • v.8 no.2
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    • pp.145-150
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    • 1999
  • To estimate the thermal effect of the vegetation canopy on the surface sublayer environment numerically, we used the combined model of Pielke's1) single layer model for vegetation and Deardorff's2) Force restore method(FRM) for soil layer. Application of present combined model to three surface conditions, ie., unsaturated bare soil, saturated bare soil and saturated vegetation canopy, showed followings; The diurnal temperature range of saturated vegetation canopy is only 20K, while saturated bare soil and unsaturated bare soil surface are 30K, 35K, respectively. The maximum temperature of vegetation canopy occurs at noon, about 2 hours earlier than that of the non-vegetation cases. The peak latent heat fluxes of vegetation canopy is simulated as a 600Wm-2 at 1300 LST. They have higher values during afternoon than beforenoon. Furthermore, the energy redistribution ratios to latent heat fluxes also increased in the late afternoon. Therefore, oasis effect driving from the vegetation canopy is reinforced during late afternoon compared with the non-vegetated conditions.

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A Study on the Feasibility Evaluation for the Use of Solar Photovoltaic Energy in Korean Peninsula Using a Satellite Image Forecasting Method (인공위성영상 예측기법을 적용한 태양광에너지 이용가능성 평가에 관한 연구)

  • Jo, Dok-Ki;Kang, Young-Heack;Auh, Chung-Moo
    • Journal of the Korean Solar Energy Society
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    • v.25 no.2
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    • pp.9-17
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    • 2005
  • Images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. For the validation, estimated solar radiation fluxes are compared with observed solar radiation fluxes at 16 sites over the Korean peninsular from January 1982 to December 2004. Estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.8 to +7.0% from the measured values and the yearly averaged horizontal global insolation of Korean peninsula was turned out to be $3.56kW/m^{2}/day$.

A Study on the Feasibility Analysis for the Use of Solar Energy in Korea Using a Satellite (인공위성을 이용한 한반도에서의 태양에너지 이용가능성 분석에 관한 연구)

  • Jo, D.K.;Kang, Y.H.;Auh, C.M.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.3
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    • pp.21-30
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    • 2002
  • Images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. For the validation. estimated solar radiation fluxes are compared with observed solar radiation fluxes at 16 sites over the Korean peninsular from January 1982 to December 2000. Estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -5.6 to +2.8% from the measured values and the yearly averaged horizontal global insolation of Korean peninsula was turned out to be $3.038kcal/m^2.day$.

Revaluation of Solar Radiation Resources in Korean Peninsular (한반도 태양에너지 자원의 재평가)

  • Jo, Dok-Ki;Yun, Chang-Yeol;Kim, Kwang-Deuk;Kang, Young-Heack
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.50-55
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    • 2009
  • Images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. For the validation, estimated solar radiation fluxes are compared with observed solar radiation fluxes at 16 sites over the Korean peninsular from January 1982 to December 2007. Estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.58 to +3.8% from the measured values and the yearly averaged horizontal global insolation of Korean peninsula was turned out to be $3.59kW/m^2/day$.

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Estimation of Land Surface Energy Fluxes using CLM and VIC model (CLM과 VIC 모형을 활용한 지표 에너지 플럭스 산정)

  • Kim, Daeun;Ray, Ram L.;King, Seokkoo;Choi, Minha
    • Journal of Wetlands Research
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    • v.18 no.2
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    • pp.166-172
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    • 2016
  • Accurate understanding of land surface is essential to analyze energy exchanges between earth surface and atmosphere. For the quantization of energy fluxes, the various researches about Land Surface Model(LSM) have been progressed. Among the various LSMs, the researches using Common Land Model(CLM) and Variable Infiltration Capacity(VIC) model are performed briskly. The CLM which is advanced LSM can calculate realistic results with few user defined parameters. The VIC model which is also typical LSM is widely used for estimation of energy fluxes and runoff in various fields. In this study, the energy fluxes which are net radiation, sensible heat flux, and latent heat flux were estimated using CLM and VIC model at Southern Sierra-Critical Zone Observatory(SS-CZO) site in California, United States. In case of net radiation and sensible heat flux, both models showed good agreement with observations, however, the CLM showed underestimated patterns of net radiation and sensible heat flux during precipitation period. In case of latent heat flux, the CLM represented better estimation of latent heat flux than VIC model which underestimated the latent heat flux. Through the estimation of energy fluxes and analysis of models' pros and cons, the applicability of CLM and VIC models and need of multi-model application were identified.

Heat Fluxes in the Marine Atmospheric Surface Layer around the Korean Peninsula based on Satellite Data (위성자료를 이용한 한반도 주변 해상 대기표층의 열속)

  • HONG, Gi-Man;KWON, Byung-Hyuk;KIM, Young-Seup
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.2
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    • pp.209-217
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    • 2005
  • The energy balance of the surface layer of the water (the Yellow Sea, the East China Sea and the East Sea) was examined using satellite data. Variations of the net heat flux were similar to those of the latent heat flux which was more intensive than the sensible heat flux. The sensible heat flux was affected the difference between the sea surface temperature and the air temperature and was less important over the Yellow Sea. The maximum of the latent heat flux occurred in autumn when the air is drier and the wind is stronger. The shortwave radiation flux decreased with the latitude and depended on the cloudiness as the longwave radiation flux does. Annual variations of heat fluxes show that the latent heat flux was more intensive over the East China Sea than the East Sea and the Yellow Sea, while the spatial differences of the other heat fluxes were weak.

Seasonal Variations of Particle Fluxes in the Bransfield Strait, Antarctica (남극 브랜스필드 해협에서 입자 플럭스 계절변화)

  • Kim, Dong-Seon;Kim, Dong-Yup;Kim, Young-June;Kang, Young-Chul
    • Ocean and Polar Research
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    • v.24 no.2
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    • pp.153-166
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    • 2002
  • Particle fluxes were measured by using time-series sediment traps in the Bransfield Strait from December 27th, 1999 to December 26th, 2000. Total mass fluxes showed distinct seasonal variations with high fluxes in the austral summer and low fluxes in the austral winter at a 678m water depth in the eastern Bransfield Strait, while they were high only in January and fairly low in other months at a 960m water depth in the central Bransfield Strait. The reason that total mass fluxes occurred only in January at a 960m water depth in the central Bransfield Strait seems to be the strong current in the surface waters, which leads to a substantial amount of terrestrial materials and locally produced organic matter being advected away from the mooring site. Total mass fluxes were very high from January to October at a 1678m water depth in the eastern Bransfield Strait, while they were high only in January and February at a 1860m water depth in the central Bransfield Strait. The fact that total mass fluxes were higher at the deep water in the both sites than at the intermediate water depth may reflect that a substantial amount of terrestrial and organic materials are laterally transported by strong tidal current from the shallow environments to the deep basins.