Surface renewal analysis for sensible and latent heat flux density

1996 ◽  
Vol 77 (3-4) ◽  
pp. 249-266 ◽  
Author(s):  
R. L. Snyder ◽  
D. Spano ◽  
K. T. Pawu
Keyword(s):  
Heat Flux ◽  
Flux Density ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Heat Flux Density ◽  
Surface Renewal ◽  
Latent Heat Flux Density

scholarly journals SURFACE ENERGY BALANCE OVER ORANGE ORCHARD USING SURFACE RENEWAL ANALYSIS

2009 ◽  
Vol 40 (4) ◽  
pp. 39
Author(s):  
Salvatore Barbagallo ◽  
Simona Consoli ◽  
Alfonso Russo
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Sensible Heat Flux ◽  
Crop Coefficient ◽  
Surface Renewal ◽  
Orange Orchard ◽  
Energy Balance Approach

Reliable estimation of surface sensible and latent heat flux is the most important process to appraise energy and mass exchange among atmosphere and biosphere. In this study the surface energy fluxes were measured over an irrigated orange orchard during 2005-2008 monitoring periods using a Surface Renewal- Energy Balance approach. The experimental area is located in a representative orchard growing area of eastern Sicily (Italy). The performance of Surface Renewal (SR) analysis for estimating sensible heat flux (H) was analysed and evaluated in terms of correlation with H fluxes from the eddy covariance (EC) method. Study revealed that the mean available energy (RN- G) and latent heat flux (LE) were of about 300 W m-2 and 237 W m-2, respectively, during dry periods and unstable-case atmospheric conditions. The estimated crop coefficient Kc values for the orchard crop averaged close to 0.80, which is considerably higher than previous FAO studies that found the value to be 0.65 for citrus with 70% of ground cover. The intercepted photosynthetically active radiation (LI PAR) by the crop was measured and relationships between LAI and crop coefficient (Kc) were established.

scholarly journals Estimation of Sensible and Latent Heat Fluxes Using Surface Renewal Method: Case Study of a Tea Plantation

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 179
Author(s):  
Jizhang Wang ◽  
Noman Ali Buttar ◽  
Yongguang Hu ◽  
Imran Ali Lakhiar ◽  
Qaiser Javed ◽  
...  
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Sensible Heat Flux ◽  
Sensible Heat ◽  
Surface Renewal ◽  
Tea Plantation ◽  
Sr Method ◽  
Renewal Method ◽  
Good Agreement

An experiment of sensible and latent heat flux measurement was conducted in a tea plantation near the Yangtze River within Danyang of Jiangsu Province, China. High-frequency (~10 Hz) air temperature measurement with fine-wire thermocouples (⌀ = 50 μm) was used for the estimation of sensible heat flux (H), and latent heat flux (LE) was extracted as a residual of the energy balance equation using additional measurements of net radiation (Rn) and soil heat flux (G). Results were compared against the eddy covariance (EC) system under unstable conditions only, and days with high precipitation were excluded from further analysis. Half-hourly datasets of the sensible heat flux estimated using the surface renewal method (SR) (HSR) and measured by the EC system (HEC) were analyzed. Results showed good agreement with R2 = 0.80, root mean square error (RMSE) = 27.87 W m−2, relative error (RE) = 9.02%, and a regression slope of 0.68—this slope was used for the calibration of the uncalibrated HSR estimated by SR. On the other hand, the half-hourly dataset of LESR was regressed against EC, and it showed good agreement with relatively high R2 = 0.93, RMSE = 32.99 W·m−2, and RE = 5.67%. Hence, the SR method may estimate the surface fluxes at a relatively low cost, ultimately improving calculations of evapotranspiration. Thus, the SR method could provide an economical tool for improving crop water management of tea plantations.

scholarly journals Sensible and Latent Heat Fluxes Over A Processing Cassava Crop with The Surface Renewal and Energy Balance Method

2021 ◽  
Author(s):  
Neilon Silva ◽  
Aureo Silva de Oliveira ◽  
Maurício Antonio Coelho Filho
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Air Temperature ◽  
High Frequency ◽  
Sensible Heat Flux ◽  
Calibration Coefficient ◽  
Sensible Heat ◽  
Surface Renewal ◽  
Sr Method

Abstract There are several methods for determining the sensible heat flux (H) on natural or agricultural surfaces. One such method is the surface renewal (SR) based on ramps of air temperature measured at high frequency by means of an ultra-thin thermocouple. The micrometeorological tower was installed (13°6'39"S, 39°16'46"W, 154 m anm) to assess the suitability of the method in estimating H on industrial cassava cultivation via calibration in relation to the eddy covariance (EC ), this consisted of a 3D anemometer. In both systems, measurements were made at a frequency of 10 Hz and comprised the period from 17/04 to 25/07/2019 (100 days). In addition to high-frequency measurements of air temperature and sonic temperature, measurements of net radiation and ground heat flux were also made, and all data grouped at 30-min intervals for determination of latent heat flux (LE) via balance solution power. It was found that (a) the SR method was adequate to estimate the sensible heat flux (H) over industrial matched with a calibration coefficient equal to 0.96; (b) under conditions of unstable atmospheric stability (daytime) the SR method showed better performance for estimating H compared to stable atmospheric conditions (nighttime); (c) the SR method proved to be adequate for estimating the latent heat flux (LE), in the industrial cassava cultivation with a high degree of correlation (r2 > 0.90), with the EC method as a reference; and (d) in the area cultivated with industrial cassava, it was found that the heat flux in the soil (G) corresponded on average to 6% of the radiation balance.

Estimating sensible and latent heat flux densities from grapevine canopies using surface renewal

2000 ◽  
Vol 104 (3) ◽  
pp. 171-183 ◽  
Author(s):  
D Spano ◽  
R.L Snyder ◽  
P Duce ◽  
K.T Paw U
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Surface Renewal

THERMAL BEHAVIOR AND IGNITION OF HIGH-ENERGY MATERIALS CONTAINING B, ALB2, AND TIB2

2020 ◽  
Author(s):  
A. G. Korotkikh ◽  
◽  
V. A. Arkhipov ◽  
I. V. Sorokin ◽  
E. A. Selikhova ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Flux Density ◽  
Ignition Delay ◽  
Delay Time ◽  
Heat Flux Density ◽  
Ignition Delay Time ◽  
High Energy ◽  
Energy Materials ◽  
High Energy Materials

The paper presents the results of ignition and thermal behavior for samples of high-energy materials (HEM) based on ammonium perchlorate (AP) and ammonium nitrate (AN), active binder and powders of Al, B, AlB2, and TiB2. A CO2 laser with a heat flux density range of 90-200 W/cm2 was used for studies of ignition. The activation energy and characteristics of ignition for the HEM samples were determined. Also, the ignition delay time and the surface temperature of the reaction layer during the heating and ignition for the HEM samples were determined. It was found that the complete replacement of micron-sized aluminum powder by amorphous boron in a HEM sample leads to a considerable decrease in the ignition delay time by a factor of 2.2-2.8 at the same heat flux density due to high chemical activity and the difference in the oxidation mechanisms of boron particles. The use of aluminum diboride in a HEM sample allows one to reduce the ignition delay time of a HEM sample by a factor of 1.7-2.2. The quasi-stationary ignition temperature is the same for the AlB2-based and AlB12-based HEM samples.

A thermoelectric device for ophthalmic heat flux density measurements: results of piloting in healthy individuals

2019 ◽  
Vol 80 (3) ◽  
pp. 45-51
Author(s):  
L. Anatychuk ◽  
N. Pasyechnikova ◽  
V. Naumenko ◽  
O. Zadorozhnyy ◽  
R. Kobylianskyi ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Density ◽  
Heat Flux Density ◽  
Thermoelectric Device ◽  
Healthy Individuals ◽  
Density Measurements
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