Predicting net radiation in naturally ventilated greenhouses based on outside global solar radiation for reference evapotranspiration estimation

2021 ◽  
Vol 257 ◽  
pp. 107102
Author(s):  
Tal Saadon ◽  
Naftali Lazarovitch ◽  
Daniela Jerszurki ◽  
Eran Tas
Keyword(s):  
Solar Radiation ◽  
Reference Evapotranspiration ◽  
Global Solar Radiation ◽  
Net Radiation ◽  
Evapotranspiration Estimation

scholarly journals Effect of solar radiation models on evapotranspiration estimation

2016 ◽  
Vol 14 (2) ◽  
pp. 247-255
Author(s):  
Milan Gocic ◽  
Mladen Milanovic ◽  
Slavisa Trajkovic
Keyword(s):  
Water Resources ◽  
Solar Radiation ◽  
Reference Evapotranspiration ◽  
Global Solar Radiation ◽  
Crop Evapotranspiration ◽  
Climatic Parameters ◽  
Evapotranspiration Estimation

The crop evapotranspiration has the great effect on defining and planning of water resources. The estimation of evapotranspiration depends on various climatic parameters. In this study, the analysis of the effect of solar radiation (Rs) on daily reference evapotranspiration (ET0) was conducted. The FAO-56 Penman-Monteith method (FAO-56 PM) was used for the estimation of ET0 in Serbia at eight meteorological stations for the period 1980-2010. The Rs was estimated using the ten one-parameter global solar radiation models. The ET0 with Almorox and Hontoria model 1 had the smallest deviation related to the ET0 with Angstr?m-Prescott (AP) model, and ET0 with To?rul et al. model 2 and Rietveld model had the greatest deviation from ET0 with AP model.

scholarly journals Performance of different methods for reference evapotranspiration estimation in Jaíba, Brazil

2018 ◽  
Vol 22 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Gustavo H. da Silva ◽  
Santos H. B. Dias ◽  
Lucas B. Ferreira ◽  
Jannaylton É. O. Santos ◽  
Fernando F. da Cunha
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Standard Method ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Air Humidity ◽  
Method Performance ◽  
Relative Air Humidity ◽  
Evapotranspiration Estimation ◽  
Missing Variables

ABSTRACT FAO Penman-Monteith (FO-PM) is considered the standard method for the estimation of reference evapotranspiration (ET0) but requires various meteorological data, which are often not available. The objective of this work was to evaluate the performance of the FAO-PM method with limited meteorological data and other methods as alternatives to estimate ET0 in Jaíba-MG. The study used daily meteorological data from 2007 to 2016 of the National Institute of Meteorology’s station. Daily ET0 values were randomized, and 70% of these were used to determine the calibration parameters of the ET0 for the equations of each method under study. The remaining data were used to test the calibration against the standard method. Performance evaluation was based on Willmott’s index of agreement, confidence coefficient and root-mean-square error. When one meteorological variable was missing, either solar radiation, relative air humidity or wind speed, or in the simultaneous absence of wind speed and relative air humidity, the FAO-PM method showed the best performances and, therefore, was recommended for Jaíba. The FAO-PM method with two missing variables, one of them being solar radiation, showed intermediate performance. Methods that used only air temperature data are not recommended for the region.

Evaluation of Some Net Radiation Models for Improving Daily Reference Evapotranspiration Estimation in Iran

2016 ◽  
Vol 142 (11) ◽  
pp. 04016051 ◽  
Author(s):  
A. A. Sabziparvar ◽  
R. Mirgaloybayat ◽  
S. Marofi ◽  
H. Zare-Abyaneh ◽  
M. Khodamorad Pour
Keyword(s):  
Reference Evapotranspiration ◽  
Net Radiation ◽  
Evapotranspiration Estimation

ESTIMATION OF NET AND SOLAR RADIATION

1971 ◽  
Vol 51 (1) ◽  
pp. 35-39 ◽  
Author(s):  
I. S. SELIRIO ◽  
D. M. BROWN ◽  
K. M. KING
Keyword(s):  
Regression Analysis ◽  
Solar Radiation ◽  
Global Solar Radiation ◽  
Daily Basis ◽  
Net Radiation ◽  
Climatological Station ◽  
The Relationship ◽  
Good Agreement

Relationships between net radiation (QN) and global solar radiation (QS) and between the ratios of QS and solar radiation at the top of the atmosphere (QS/QA) and duration of bright sunshine and daylength (n/N) were determined by regression analysis at Guelph, Ontario, Canada. The data used were recorded at the Guelph O.A.C. climatological station from March, 1964 to February, 1969. Results showed that during the spring, summer, and autumn seasons, QS alone can be used to estimate QN satisfactorily. Daily values of QN are about 50% of QS. The relationship derived for estimating QS from duration of bright sunshine (n) showed good agreement with findings of previous workers. QS varies between 20 and 80% of QA for overcast to cloudless days. The relationships derived in this study can be used to estimate net and solar radiation on a daily basis when these measurements are unavailable.

scholarly journals Estimation methods of reference evapotranspiration (ETo) for Uberlândia -MG

2015 ◽  
Vol 35 (1) ◽  
pp. 27-38 ◽  
Author(s):  
ZILDA C. DE LACERDA ◽  
JOSÉ E. P. TURCO
Keyword(s):  
Solar Radiation ◽  
Reference Evapotranspiration ◽  
Global Solar Radiation ◽  
Daily Basis ◽  
Meteorological Station ◽  
Estimation Methods ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Daily Data ◽  
Analysis Of Results

One approach to verify the adequacy of estimation methods of reference evapotranspiration is the comparison with the Penman-Monteith method, recommended by the United Nations of Food and Agriculture Organization - FAO, as the standard method for estimating ET0. This study aimed to compare methods for estimating ET0, Makkink (MK), Hargreaves (HG) and Solar Radiation (RS), with Penman-Monteith (PM). For this purpose, we used daily data of global solar radiation, air temperature, relative humidity and wind speed for the year 2010, obtained through the automatic meteorological station, with latitude 18° 91' 66" S, longitude 48° 25' 05" W and altitude of 869m, at the National Institute of Meteorology situated in the Campus of Federal University of Uberlandia - MG, Brazil. Analysis of results for the period were carried out in daily basis, using regression analysis and considering the linear model y = ax, where the dependent variable was the method of Penman-Monteith and the independent, the estimation of ET0 by evaluated methods. Methodology was used to check the influence of standard deviation of daily ET0 in comparison of methods. The evaluation indicated that methods of Solar Radiation and Penman-Monteith cannot be compared, yet the method of Hargreaves indicates the most efficient adjustment to estimate ETo.

scholarly journals Radiation balance of coffee hedgerows

2008 ◽  
Vol 12 (3) ◽  
pp. 274-281 ◽  
Author(s):  
Luiz R. Angelocci ◽  
Fábio R. Marin ◽  
Felipe G. Pilau ◽  
Evandro Z. Righi ◽  
José L. Favarin
Keyword(s):  
Solar Radiation ◽  
Cover Crops ◽  
Ground Cover ◽  
Global Solar Radiation ◽  
Important Variable ◽  
Field Conditions ◽  
Radiation Balance ◽  
Net Radiation ◽  
Energy Exchanges ◽  
Good Agreement

The radiation balance of hedgerows is an important variable in studies of mass and energy exchanges between parcial ground cover crops and the atmosphere. This paper describes a device with eight net radiometers encompassing the plants of a hedgerow. The radiometers were moved along a length of hedgerow, in a continuous and reversible movement. The canopy net radiation in this length (Rnc) was found by integration of the measurements over the notional cylinder formed. The device showed good performance and provided reliable measurements of Rnc of coffee hedgerows, showing itselfto be an useful technique of measurement in field conditions. Good correlations between Rnc and global solar radiation, turfgrass and coffee crop net radiation were found in 15-min, daytime and 24-hr periods, allowing the possibility of estimating Rnc from these simple measurements. Beer’s law was also used to have an independent estimation of Rnc. A good agreement was found between values of Rnc estimated by this law of attenuation and those integrated by the device in periods of 15 min, with overestimation of 10%, whereas for values integrated over daytime periods the agreement was not satisfactory.

Estimation of net radiation for a coniferous forest, and the effects of logging on net radiation and the reflection coefficient

1978 ◽  
Vol 8 (4) ◽  
pp. 450-455 ◽  
Author(s):  
J. H. McCaughey
Keyword(s):  
Reflection Coefficient ◽  
Solar Radiation ◽  
Coniferous Forest ◽  
Field Studies ◽  
Global Solar Radiation ◽  
Balsam Fir ◽  
Net Radiation ◽  
Linear Regression Equation ◽  
Simple Linear Regression ◽  
Clear Cut

The results of field studies on the radiation climate at Montmorency, Quebec, are presented. These studies were conducted in the summers of 1975 and 1976, and two sites were used. The first site, used in both years, was forested with 50- to 60-year-old balsam fir (Abiesbalsamea L. Mill.). The second site, originally forested with balsam fir, was clear-cut in the fall of 1975. The daily mean reflection coefficient for solar radiation of the forest is 7% (sample of 264 hourly values). In contrast, the clear-cut site has a daily mean reflection coefficient of 18% (sample of 171 hourly values). There is no evidence of a systematic variation of hourly reflection coefficients with solar zenith angle for either site. The effect of logging on net radiation is characterized by a sample of 21 days in 1976 when hourly values of net radiation were available for both sites. Typically, during the night, the magnitude of net radiation on the forested site is less than that on the clear-cut site, and during the day, the net radiation on the clear-cut site is less than that on the forested site. In terms of daily totals, the effect of logging is to reduce net radiation by 10%.A simple linear regression equation for the calculation of net radiation for the forested site is presented. Global solar radiation (hourly values) is used as the predictor. The parameters of the model are similar to other equations for similar surfaces.

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