scholarly journals LAS-Derived Determination of Surface-Layer Sensible Heat Flux over a Heterogeneous Urban Area

Atmosphere ◽  
2015 ◽  
Vol 25 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Sang-Hyun Lee
Keyword(s):  
Heat Flux ◽  
Surface Layer ◽  
Urban Area ◽  
Sensible Heat Flux ◽  
Sensible Heat

Determination of sensible heat flux over Sahelian fallow savannah using infra-red thermometry

1994 ◽  
Vol 68 (1-2) ◽  
pp. 93-105 ◽  
Author(s):  
J.-P. Lhomme ◽  
B. Monteny ◽  
A. Chehbouni ◽  
D. Troufleau
Keyword(s):  
Heat Flux ◽  
Sensible Heat Flux ◽  
Sensible Heat ◽  
Infra Red

scholarly journals RELAÇÃO ENTRE VELOCIDADE DO VENTO E ENERGIA CINÉTICA TURBULENTA EM MODELOS SIMPLIFICADOS DA CAMADA LIMITE NOTURNA

2016 ◽  
Vol 38 ◽  
pp. 75
Author(s):  
Rafael Maroneze ◽  
Otávio Costa Acevedo ◽  
Felipe Denardin Costa
Keyword(s):  
Heat Flux ◽  
Sensible Heat Flux ◽  
Turbulent Fluxes ◽  
Turbulent Intensity ◽  
Simplified Model ◽  
Sensible Heat ◽  
Temperature Variance ◽  
Stable Conditions ◽  
Atmospheric Coupling

The determination of the turbulent fluxes in very stable conditions is done, generally, through parameterizations. In this work the turbulent fluxes are estimated, by using a simplified model, through prognostic equations for the turbulent intensity, the sensible heat flux and the temperature variance. The results indicate that the model is able to reproduce both atmospheric coupling and the intermittent character of the turbulence in very stable conditions.

scholarly journals Four-year (2006–2009) eddy covariance measurements of CO<sub>2</sub> flux over an urban area in Beijing

2012 ◽  
Vol 12 (17) ◽  
pp. 7881-7892 ◽  
Author(s):  
H. Z. Liu ◽  
J. W. Feng ◽  
L. Järvi ◽  
T. Vesala
Keyword(s):  
Heat Flux ◽  
Urban Area ◽  
Eddy Covariance ◽  
Sensible Heat Flux ◽  
Source Area ◽  
Carbon Dioxide Flux ◽  
Heat Fluxes ◽  
Urban Surface ◽  
Sensible Heat ◽  
Main Component

Abstract. Long-term measurements of carbon dioxide flux (Fc) and the latent and sensible heat fluxes were performed using the eddy covariance (EC) method in Beijing, China over a 4-yr period in 2006–2009. The EC setup was installed at a height of 47 m on the Beijing 325-m meteorological tower in the northwest part of the city. Latent heat flux dominated the energy exchange between the urban surface and the atmosphere in summer, while sensible heat flux was the main component in the spring. Winter and autumn were two transition periods of the turbulent fluxes. The source area of Fc was highly heterogeneous, which consisted of buildings, parks, and highways. It was of interest to study of the temporal and spatial variability of Fc in this urban environment of a developing country. Both on diurnal and monthly scale, the urban surface acted as a net source for CO2 and downward fluxes were only occasionally observed. The diurnal pattern of Fc showed dependence on traffic and the typical two peak traffic patterns appeared in the diurnal cycle. Also Fc was higher on weekdays than on weekends due to the higher traffic volumes on weekdays. On seasonal scale, Fc was generally higher in winter than during other seasons likely due to domestic heating during colder months. Total annual average CO2 emissions from the neighborhood of the tower were estimated to be 4.90 kg C m−2 yr−1 over the 4-yr period. Total vehicle population was the most important factor controlling the inter-annual variability of Fc in this urban area.

scholarly journals Spatial variations of sensible heat flux over an urban area measured using Doppler lidar

2008 ◽  
Vol 15 (3) ◽  
pp. 367-380 ◽  
Author(s):  
J. C. Davis ◽  
C. G. Collier ◽  
F. Davies ◽  
K. E. Bozier
Keyword(s):  
Heat Flux ◽  
Urban Area ◽  
Sensible Heat Flux ◽  
Spatial Variations ◽  
Doppler Lidar ◽  
Sensible Heat

Determination of sensible heat flux over sparse canopy using thermal infrared data

1989 ◽  
Vol 44 (3-4) ◽  
pp. 197-216 ◽  
Author(s):  
W.P Kustas ◽  
B.J Choudhury ◽  
M.S Moran ◽  
R.J Reginato ◽  
R.D Jackson ◽  
...  
Keyword(s):  
Heat Flux ◽  
Sensible Heat Flux ◽  
Thermal Infrared ◽  
Sensible Heat ◽  
Sparse Canopy ◽  
Infrared Data

scholarly journals The evaluating study of the momentum and heat exchange process of two surface layer schemes during the severe haze pollution in east China

2018 ◽  
Author(s):  
Yue Peng ◽  
Hong Wang ◽  
Yubin Li ◽  
Changwei Liu ◽  
Tianliang Zhao ◽  
...  
Keyword(s):  
Heat Flux ◽  
Surface Layer ◽  
Momentum Flux ◽  
Roughness Length ◽  
Sensible Heat Flux ◽  
Heat Fluxes ◽  
Chemical Model ◽  
East China ◽  
Sensible Heat ◽  
Haze Pollution

Abstract. The turbulent flux parameterization schemes in surface layer are crucial for air pollution modeling. The pollutants prediction by atmosphere chemical model exist obvious deficiencies, which may be closely related to the uncertainties of the momentum and sensible heat fluxes calculation in the surface layer. In this study, a new surface layer scheme (Li) and a classic scheme (MM5) were compared and evaluated based on the observed momentum and sensible heat fluxes in east China during a severe haze episode in winter. The results showed that it is necessary to distinguish the thermal roughness length z0h from the aerodynamic roughness length z0m, and ignoring the difference between the two led to large errors of the momentum and sensible heat fluxes in MM5. The error of calculated sensible heat flux was reduced by 54 % after discriminating z0h from z0m in MM5. Besides, the algorithm itself of Li scheme performed generally better than MM5 in winter in east China and the momentum flux bias of the Li scheme was lower about 12%, sensible heat flux bias about 5 % than those of MM5 scheme. Most of all, the Li scheme showed a significant advantage over MM5 for the transition stage from unstable to stable atmosphere corresponding to the PM2.5 accumulation. The momentum flux bias of Li was lower about 38 %, sensible heat flux bias about 43 % than those of MM5 during the PM2.5 increasing stage. This study result indicates the ability of Li scheme for more accurate describing the regional atmosphere stratification, and suggests the potential improving possibilities of severe haze prediction in east China by online coupling it into the atmosphere chemical model.

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