Long‐wave radiation from clear skies

Swinbank, W. C.

doi:10.1002/qj.49708938105

Cited by 1,301 publications

(174 citation statements)

References 5 publications

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“…Water infiltration is calculated using the Green and Ampt approximation to Richard's equation (Chow et al, 1988). Lateral water transfers in the soil are simulated using a 1D kinematic wave model (Singh, 1997). Infiltration and lateral subsurface flows are controlled by soil hydraulic properties (hydraulic conductivity, porosity) and by the topographic gradient.…”

Section: Ecohydrologic Modelmentioning

confidence: 99%

Climate and topographic controls on simulated pasture production in a semiarid Mediterranean watershed with scattered tree cover

Lozano‐Parra

Maneta

Schnabel

2014

Hydrol. Earth Syst. Sci.

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Abstract. Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatiotemporal variations of pasture production at the decadal-century scales over whole watersheds are poorly known. We used a physically based, spatially distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300-year-long synthetic daily climate data set generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under the current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production but more interannual variability. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long-term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.

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Section: Ecohydrologic Modelmentioning

confidence: 99%

Climate and topographic controls on simulated pasture production in a semiarid Mediterranean watershed with scattered tree cover

Lozano‐Parra

Maneta

Schnabel

2014

Hydrol. Earth Syst. Sci.

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“…The RMSEs ranged from 30 -45 W m -2 for clear sky days. They determined that four models (Brunt 1932;Swinbank 1963;Brutsaert 1975;Prata 1996) were superior in performance to sixteen other models tested in their study. Most recently, Choi et al (2008) tested five models for clear sky conditions, thereby demonstrating that the Brunt (1932) and Brutsaert (1975) models performed the best at eleven studied sites in Florida, USA.…”

Section: R Ld From Flux Towersmentioning

confidence: 97%

Satellite Based Downward Long Wave Radiation by Various Models in Northeast Asia

Sur¹,

Kim²,

Choi³

2014

Terr. Atmos. Ocean. Sci.

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Satellite-based downward long wave radiation measurement under clear sky conditions in Northeast Asia was conducted using five well-known physical models (Brunt 1932, Idso and Jackson 1969, Brutsaert 1975, Satterlund 1979, Prata 1996 with a newly proposed global R ld model (Abramowitz et al. 2012). Data from two flux towers in South Korea were used to validate downward long wave radiation. Moderate resolution imaging spectroradiometer (MODIS) atmospheric profile products were used to develop the R ld models. The overall root mean square error (RMSE) of MODIS R ld with respect to two ecosystem-type flux towers was determined to be ≈ 20 W m -2 . Based on the statistical analyses, MODIS R ld estimates with Brutsaert (1975) and Abramowitz et al. (2012) models were the most applicable for evaluating R ld for clear sky conditions in Northeast Asia. The Abramowitz R ld maps with MODIS T a and e a showed reasonable seasonal patterns, which were wellaligned with other biophysical variables reported by previous studies. The MODIS R ld map developed in this study will be very useful for identifying spatial patterns that are not detectable from ground-based R ld measurement sites.

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“…In the model, those aspects are configurable. For the clear sky temperature, the correlation from (Swinbank, 1963) is used.…”

Section: Wall Modelmentioning

confidence: 99%

Cabin Thermal Needs: Modeling and Assumption Analysis

Brèque¹,

Nemer²

2017

Linköping Electronic Conference Proceedings

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Interest for cabin thermal needs has strongly increased for the past 10 years, particularly due to heating. Indeed, the development of electric and hybrid vehicles stressed the need to rethink the cabin thermal design and the HVAC, this high-consuming auxiliary, which can dramatically decrease the vehicle electric range. Thus, this paper presents a detailed transient and mono-zonal model of a car cabin in order to predict the thermal needs. The model is developed using the MODELICA language via the DYMOLA environment. It considers conduction, convection, radiation heat transfers as well as the HVAC and water vapor impacts. The different assumptions of the model are discussed and important considerations usually not discussed are highlighted. The thermal loads are also analyzed. Finally, the heating and cooling thermal needs are computed for steady state mode and for convergence mode as well as for varying recirculation ratios. This work is useful to better understand the whys and wherefores related to the cabin thermal needs.

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Long‐wave radiation from clear skies

Cited by 1,301 publications

References 5 publications

Climate and topographic controls on simulated pasture production in a semiarid Mediterranean watershed with scattered tree cover

Climate and topographic controls on simulated pasture production in a semiarid Mediterranean watershed with scattered tree cover

Satellite Based Downward Long Wave Radiation by Various Models in Northeast Asia

Cabin Thermal Needs: Modeling and Assumption Analysis

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