scholarly journals Comparison of Pyranometric and Pyrheliometric Methods for the Determination of Sunshine Duration

2007 ◽  
Vol 24 (5) ◽  
pp. 835-846 ◽  
Author(s):  
Yvonne B. L. Hinssen ◽  
Wouter H. Knap
Keyword(s):  
Solar Irradiance ◽  
Extreme Values ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Surface Radiation ◽  
Global Irradiance ◽  
Correlation Algorithm ◽  
Mean Differences ◽  
Radiation Measurements

Abstract Two pyranometric methods for the determination of sunshine duration (SD) from global irradiance measurements are evaluated by means of summated sunshine seconds derived from pyrheliometric measurements in combination with the WMO threshold of 120 W m−2 for the direct solar irradiance. The evaluation is performed using direct and global radiation measurements made at the Cabauw Baseline Surface Radiation Network (BSRN) site in the Netherlands for the period March 2005–February 2006. The “Slob algorithm” uses 10-min mean and extreme values of the measured global irradiance and parameterized estimates of the direct and diffuse irradiance. The “correlation algorithm” directly relates SD to 10-min mean measurements of global irradiance. The cumulative pyrheliometric SD for the mentioned period is 1429 h. Relative to this value, the Slob algorithm and correlation algorithm give −72 h (−5%) and +8 h (+0.6%). On a daily mean basis, the values are −0.22 ± 0.05 h day−1 and 0.03 ± 0.03 h day−1, respectively. By means of tuning the irradiance parameterizations of the Slob algorithm, the yearly cumulative and daily mean differences can be reduced to +7 h (+0.5%) and 0.02 ± 0.04 h day−1, respectively. It is concluded that, by use of either algorithm, it is possible to estimate daily sums of SD from 10-min mean measurements of global irradiance with a typical uncertainty of 0.5–0.7 h day−1. For yearly sums, the uncertainty typically amounts to 0.5%.

Solar irradiance, air pollution and temperature changes in the Arctic

1995 ◽  
Vol 352 (1699) ◽  
pp. 247-258 ◽  
Keyword(s):  
Air Pollution ◽  
Spatial Distribution ◽  
Solar Irradiance ◽  
Early Spring ◽  
Surface Radiation ◽  
The Arctic ◽  
Radiation Balance ◽  
Temperature Changes ◽  
Global Irradiance ◽  
Arctic Haze

A highly significant decrease in the annual sums of global irradiance reaching the surface of the Arctic, averaging 0.36 W m -2 per year, was derived from an analysis of 389 complete years of measurement, beginning in 1950, at 22 pyranometer stations within the Arctic Circle. The smaller data base of radiation balance measurements available showed a much smaller and statistically non-significant change. Reductions in global irradiance were most frequent in the early spring months and in the western sectors of the Arctic, coinciding with the seasonal and spatial distribution of the incursions of polluted air which give rise to the Arctic Haze. Irradiance measured in Antarctica during the same period showed a similar and more widespread decline despite the lower concentrations of pollutants. A marked increase in the surface radiation balance was recorded. Possible reasons for these interpolar anomalies and their consequences for temperature change are discussed.

scholarly journals SARAH-3 - a new satellite-based Cimate Data Record for surface radiation parameters from the CM SAF

2021 ◽  
Author(s):  
Uwe Pfeifroth ◽  
Jaqueline Drücke ◽  
Jörg Trentmann ◽  
Rainer Hollmann
Keyword(s):  
Water Cycle ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Surface Radiation ◽  
Climate Data ◽  
Surface Solar Radiation ◽  
Data Set ◽  
Time Period ◽  
Data Record ◽  
Climate Data Record

<p>The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) generates and distributes high quality long-term climate data records (CDR) of energy and water cycle parameters, which are freely available.</p><p>In fall 2021, a new version of the “Surface Solar Radiation data set – Heliosat” will be released: SARAH-3. As the previous editions, the SARAH-3 climate data record is based on satellite observations from the first and second METEOSAT generations and provides various surface radiation parameters, including global radiation, direct radiation, sunshine duration, photosynthetic active radiation and others. SARAH-3 covers the time period 1983 to 2020 and offers 30-minute instantaneous data as well as daily and monthly means on a regular 0.05° x 0.05° lon/lat grid.</p><p>In this presentation, an overview of the SARAH climate data record and their applications will be provided. A focus will be on the SARAH-3 developments and improvements (i.e. improved consideration of snow-covered surfaces). First validation results of the new Climate Data Record using surface reference observations will be presented. Further, SARAH-3 will be used for the analysis of the climate variability in Europe during the last decades.</p><p>. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .</p>

scholarly journals Spatial distribution of coefficients for determination of global radiation in Serbia

2012 ◽  
Vol 27 (3) ◽  
pp. 254-259
Author(s):  
Jugoslav Nikolic ◽  
Djordje Nikolic
Keyword(s):  
Spatial Distribution ◽  
Sunshine Duration ◽  
Renewable Energy Sources ◽  
Global Radiation ◽  
Distribution Coefficients ◽  
Shortwave Radiation ◽  
Radiation Balance ◽  
Direct Measurements ◽  
Wide Range

The aim of this paper is a creation of the spatial distribution of the corresponding coefficients for the indirect determination of global radiation using all direct measurements data of this shortwave radiation balance component in Serbia in the standard climate period (1961-1990). Based on the global radiation direct measurements data recorded in the past and routine measurements/observations of cloudiness and sunshine duration, the spatial distribution coefficients maps required for calculation of global radiation were produced on the basis of sunshine/cloudiness in an arbitrary point on the territory of Serbia. Besides, a specific verification of the proposed empirical formula was performed. This paper contributes to a wide range of practical applications as direct measurements of global radiation are relatively rare, and are not carried out in Serbia today. Significant application is possible in the domain of renewable energy sources. The development of method for determination of the global radiation has an importance from the aspect of the environmental protection; however it also has an economic importance through applications in numerous commercial projects, as it does not require special measurements or additional financial investments.

SARAH-3 – a new satellite-based Climate Data Record of Surface Solar Radiation parameters

2021 ◽  
Author(s):  
Uwe Pfeifroth ◽  
Jaqueline Drücke ◽  
Jörg Trentmann ◽  
Rainer Hollmann
Keyword(s):  
Solar Radiation ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Surface Radiation ◽  
Climate Data ◽  
Regional Variability ◽  
Surface Solar Radiation ◽  
Data Set ◽  
Data Record ◽  
Climate Data Record

<p class="western"><span lang="en-US">The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) generates and distributes high quality long-term climate data records (CDR) of energy and water cycle parameters, which are freely available.</span></p> <p class="western"><span lang="en-US">In 2022, a new version of the “Surface Solar Radiation data set – Heliosat” will be released: SARAH-3. As the previous editions, the SARAH-3 climate data record is based on satellite observations from the first and second METEOSAT generations and provides various surface radiation parameters, including global radiation, direct radiation, sunshine duration, photosynthetic active radiation and others. SARAH-3 covers the time period 1983 to 2020 and offers 30-minute instantaneous data as well as daily and monthly means on a regular 0.05° x 0.05° lon/lat grid.</span></p> <p class="western" align="left"><span lang="en-US">In this presentation, an overview of the SARAH climate data record and their applications will be given. A focus will be on the SARAH-3 developments and validation with surface reference observations. Further, SARAH-3 will be used for a first analysis of the climate variability and potential trends of global radiation in Europe during the last decades. </span><span lang="en-US">The data record reveals that there is an increasing trend of surface solar radiation in Europe during the last decades, which is superimposed by decadal and regional variability.</span></p>

The effect of grass transpiration on the air temperature

Biologia ◽  
2014 ◽  
Vol 69 (11) ◽  
Author(s):  
Miloslav Šír ◽  
Miroslav Tesař ◽  
Ľubomír Lichner ◽  
Henryk Czachor
Keyword(s):  
Air Temperature ◽  
Root Zone ◽  
Sunshine Duration ◽  
Global Radiation ◽  
Maximum Intensity ◽  
Vegetative Cover ◽  
Brown Forest Soil ◽  
Large Area ◽  
Avenella Flexuosa ◽  
Daily Total

AbstractOscillations of the air temperature and tensiometric pressure of the soil water were measured in the experimental slope Tomšovka (Czech Republic, Jizera Mts, 822 m a.s.l.). The brown forest soil (Dystric Cambisols) is covered with Calamagrostis villosa, Avenella flexuosa and Vaccinium myrtilus. Thermometers were placed at a height of 5 and 200 cm above the grassland. The tensiometer was installed in the root zone of grass at a depth of 15 cm. Oscillations in a cloudless day, August 24, 2001, (sunshine duration 12.1 hour/day, daily total of global radiation 22.4 MJ/m2/day, maximum intensity of global radiation 1008 W/m2, transpiration 13.7 MJ/m2/day) were analysed in detail. The oscillations with a period of about 30 to 60 minutes were recorded in the air temperature course taken from 11 am to 5 pm. At the height of 200 cm oscillations ranged from 24 to 28°C. Concurrently, in the depth of 15 cm, the oscillations of tensiometric pressure in the range of −6 to −11 kPa were recorded from 8 am to 4 pm. It was concluded that the oscillations in the air temperature resulted from autonomous and self-regulated oscillations in the intensity of transpiration. It is evident that the 2-m air temperature was significantly influenced by transpiration of plants around the large area. The fact that the air temperature oscillated sharply confirms that the rate of transpiration was synchronized in this area. Vegetative cover thus created a self-regulated superorganism that substantially affected the temperature of the near-ground atmosphere layer.

Determination of activity of 51Cr on gamma radiation measurements

2017 ◽  
Vol 48 (1) ◽  
pp. 1-4
Author(s):  
V. V. Gorbachev ◽  
V. N. Gavrin ◽  
T. V. Ibragimova ◽  
A. V. Kalikhov ◽  
Yu. M. Malyshkin ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Determination Of Activity ◽  
Radiation Measurements

scholarly journals Albedo and estimates of net radiation for green beans under polyethylene cover and field conditions

1999 ◽  
Vol 34 (10) ◽  
pp. 1763-1774 ◽  
Author(s):  
José Leonaldo de Souza ◽  
João Francisco Escobedo ◽  
Maria Terezinha Trovareli Tornero
Keyword(s):  
Solar Irradiance ◽  
Field Conditions ◽  
Net Radiation ◽  
Phaseolus Vulgaris L ◽  
Green Beans ◽  
Phenological Stages ◽  
Independent Variables ◽  
Clear Sky ◽  
Solar Elevation ◽  
Global Irradiance

This paper describes the albedo (r) and estimates of net radiation and global solar irradiance for green beans crop (Phaseolus vulgaris L.), cultivated in greenhouse with cover of polyethylene and field conditions, in Botucatu, SP, Brazil (22º 54' S; 48º 27' W; 850 m). The solar global irradiance (Rg) and solar reflected radiation (Rr) were used to estimate the albedo through the ratio between Rr and Rg. The diurnal curves of albedo were obtained for days with clear sky and partially cloudy conditions, for different phenological stages of the crop. The albedo ranged with the solar elevation, the environment and the phenological stages. The cloudiness range have almost no influence on the albedo diurnal amount. The estimation of radiation were made by linear regression, using the global solar irradiance (Rg) and net short-waves radiation (Rc) as independent variables. All estimates of radiation showed better adjustment for specific phenological periods compared to the entire crop growing cycle. The net radiation in the greenhouse has been estimated by the global solar irradiance measured at field conditions.

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