Modelling frequency distributions of 5 minute-averaged solar radiation indexes using Beta probability functions

2003 ◽  
Vol 75 (3-4) ◽  
pp. 213-224 ◽  
Author(s):  
H. F. Assun��o ◽  
J. F. Escobedo ◽  
A. P. Oliveira
Keyword(s):  
Solar Radiation ◽  
Probability Functions ◽  
Frequency Distributions

Thermal loading of concrete bridges

1984 ◽  
Vol 11 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Malcolm J. S. Hirst
Keyword(s):  
Solar Radiation ◽  
Engineering Design ◽  
Computer Model ◽  
Parametric Study ◽  
Structural Engineering ◽  
Thermal Loading ◽  
Design Method ◽  
Field Measurements ◽  
Concrete Bridges ◽  
Frequency Distributions

This paper presents the results of a parametric study into the thermal loading of concrete bridges by solar radiation. All results were obtained using a computer model calibrated from field measurements. The model computes the loading parameters from the bridge characteristics and the standard daily records of the weather bureau. The design method given uses an effective thickness concept to find the effects of a wearing course on the temperature profile of the underlying bridge. Thermal loading depends on climate and is extremely variable. Histograms are presented, which show the frequency distributions of the loading parameters for sample bridges at three Australian sites covering a range of climatic regimes from tropical to temperate. Key words: bridges, concrete, loads, temperature, solar radiation, structural engineering, design chart.

Frequency Distributions for Hourly and Daily Clearness Indices

2001 ◽  
Author(s):  
Manuel Ibañez ◽  
William A. Beckman ◽  
Sanford A. Klein
Keyword(s):  
Solar Radiation ◽  
Recent Literature ◽  
Weather Data ◽  
Clearness Index ◽  
Frequency Distributions ◽  
The Us ◽  
Daily Frequency ◽  
Better Than ◽  
Exponential Probability

Abstract The clearness index for hourly and daily radiation is an important parameter in describing solar radiation. Liu and Jordan demonstrated that the monthly average daily clearness index could be used to predict the long-term distribution of daily solar radiation in a month. This paper reviews recent literature on the prediction of hourly and daily frequency distributions and cumulative frequency distributions of clearness indices. Ten years of measured weather data for six cities in the US are used to investigate the nature of the hourly and daily frequency distributions. A second set of ten years of data for six cities is used to verify the predictions. A bi-exponential probability density function is proposed that fits the observed bimodal nature of the data better than existing models. A case is made for the function being universal.

scholarly journals Transmission of Solar Radiation by Clouds over Snow and Ice Surfaces. Part II: Cloud Optical Depth and Shortwave Radiative Forcing from Pyranometer Measurements in the Southern Ocean

2005 ◽  
Vol 18 (22) ◽  
pp. 4637-4648 ◽  
Author(s):  
Melanie F. Fitzpatrick ◽  
Stephen G. Warren
Keyword(s):  
Solar Radiation ◽  
Southern Ocean ◽  
Sea Ice ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Surface Albedo ◽  
Cloud Droplet ◽  
Frequency Distributions ◽  
Cloud Optical Depth ◽  
Cloud Radiative Forcing

Abstract Downward solar irradiance at the sea surface, measured on several voyages of an icebreaker in the Southern Ocean, is used to infer transmittance of solar radiation by clouds. Together with surface albedo estimated from coincident hourly sea ice reports, instantaneous cloud radiative forcing and effective cloud optical depth are obtained. Values of “raw cloud transmittance” (trc), the ratio of downward irradiance under cloud to downward irradiance measured under clear sky, vary from 0.1 to 1.0. Over sea ice, few values of trc were observed between 0.8 and 1.0, possibly due to the threshold nature of the aerosol-to-cloud-droplet transition. This sparsely populated region of transmittances is referred to as the Köhler gap. The instantaneous downward shortwave cloud radiative forcing is computed, as well as the time-averaged net forcing. The net forcing at a solar zenith angle of 60° is typically −250 W m−2 over open ocean, but only half this value over sea ice because of the higher surface albedo and less frequent occurrence of clouds. “Effective” optical depths τ (for a radiatively equivalent horizontally homogeneous cloud) are classified by season and surface type. The frequency distributions of τ are well fitted by decaying exponentials, giving a characteristic optical depth of 15 at 47°S, increasing to 24 in the region of maximum cloud cover at 58°S, and decreasing to 11 at 67°S near the coast of Antarctica.

Frequency Distributions for Hourly and Daily Clearness Indices

2001 ◽  
Vol 124 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Manuel Iban˜ez ◽  
William A. Beckman ◽  
Sanford A. Klein
Keyword(s):  
Solar Radiation ◽  
Recent Literature ◽  
Weather Data ◽  
Clearness Index ◽  
Frequency Distributions ◽  
Monthly Average ◽  
Daily Frequency ◽  
Better Than ◽  
Exponential Probability

The clearness index for hourly and daily radiation is an important parameter in describing solar radiation. Liu and Jordan demonstrated that the monthly average daily clearness index could be used to predict the long-term distribution of daily solar radiation in a month. This paper reviews recent literature on the prediction of hourly and daily frequency distributions and cumulative frequency distributions of clearness indices. Ten years of measured weather data for six cities in the U.S. are used to investigate the nature of the hourly and daily frequency distributions. A second set of ten years of data for six cities is used to verify the predictions. A bi-exponential probability density function is proposed that fits the observed bimodal nature of the data better than existing models. A case is made for the function being universal.

scholarly journals Inheritance of High Sugars from Tomato Accession PI 270248 and Environmental Variation between Seasons

2006 ◽  
Vol 131 (1) ◽  
pp. 41-45 ◽  
Author(s):  
N. Georgelis ◽  
J.W. Scott ◽  
E.A. Baldwin
Keyword(s):  
Solar Radiation ◽  
Lycopersicon Esculentum ◽  
Inbred Line ◽  
Broad Sense Heritability ◽  
Cherry Tomato ◽  
Frequency Distributions ◽  
High Sugar ◽  
Polygenic Control ◽  
Significant Line ◽  
Dominance Variation

Small-fruited cherry tomato accession PI 270248 [Lycopersicon esculentum Mill. var. cerasiforme (Dunal) A. Gray] with high fruit sugars was crossed to large-fruited inbred line Fla.7833-1-1-1 (7833) (L. esculentum) that had normal (low) fruit sugars. The F1 was crossed to PI 270248 and 7833 to obtain BCP1 and BCP2, respectively, and self-pollinated to obtain F2 seed. The resulting population was used to study the inheritance of high sugars from PI 270248. Continuous sugar level frequency distributions of BCP1, BCP2, and F2 suggest that the trait is under polygenic control. Additive variation was significant, but dominance variation was not. There was a heterozygote × heterozygote type of epistasis present that likely caused the F1 sugar level to skew nearly to the level of the high sugar parent. The F2 mean sugar level was lower than the midparent level. Broad-sense heritability was 0.86. There was a significant line × season (fall, spring) interaction where lines with higher sugars were affected more by seasons than lines with lower sugars. Sugar level, in general, was higher in spring. Higher solar radiation in spring than in fall may explain the sugar level difference between the seasons.

scholarly journals Solar radiation characteristics at Qena / Egypt

MAUSAM ◽  
2021 ◽  
Vol 49 (1) ◽  
pp. 59-70
Author(s):  
SAYED M. EL-SHAZL ◽  
Y.A.M. ABDELMAGEED ◽  
M. EL-NOUBI ADAM
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Dust Particles ◽  
Atmospheric Conditions ◽  
Climatic Effects ◽  
Study Region ◽  
Frequency Distributions ◽  
Diffuse Fraction ◽  
Low Degree ◽  
Aerosol Dust

Measurements of the hourly global solar radiation (G) and its diffuse component (D) on a horizontal surface have been carried out in Qena / Upper Egypt in the period from June 1992 to May 1993. The corresponding diffuse fraction (DIG) is calculated. Diurnal variations of the results have been studied. Also the daily totals values and its monthly and seasonal averages as well as their frequency distributions were computed and examined. The seasonal and climatic effects on the fluctuation of the results are discussed. These effects were particularly large during spring and Winter months owing to the high fluctuation of the atmospheric conditions with aspect to amount of clouds, water content, and concentration of aerosol dust particles. The influence of clouds is also considered. It shows small effect on the results (4.5%), reflecting the low degree of cloudiness in the study region. The relation between the diffuse fraction and clearness index (G/Go) shows that most of the points lies in the region of the high availability of the incoming solar radiation. In general the study shows clearly the abundance of solar energy in Qena / Egypt, and the suitability of its climate for using it in different applications.

scholarly journals Potential of Wind and Solar Electricity Generation in Bangladesh

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Sanjoy Kumar Nandi ◽  
Mohammad Nasirul Hoque ◽  
Himangshu Ranjan Ghosh ◽  
Swapan Kumar Roy
Keyword(s):  
Solar Radiation ◽  
Alternative Energy ◽  
Sunshine Duration ◽  
Global Solar Radiation ◽  
Environmental Benefits ◽  
Wind Data ◽  
Energy Sources ◽  
Energy Potential ◽  
Frequency Distributions ◽  
Wind Speeds

Wind and solar energies are the alternative energy sources that can be used to supplement the conventional energy sources particularly in Bangladesh. In this work, the aim is to assess the current wind and solar energy potential in Bangladesh. The wind data for the five stations obtained from Local Government Engineering Department have been assessed, but only two of them seem to be eligible for energy production. Annual average, monthly average, and hourly average wind speeds and wind power densities were calculated from the wind data. The Weibull distribution parameters (c and k), the dominant wind directions, and the frequency distributions were also determined. Experimentally measured solar radiation data are not available over Bangladesh. Measured climatological data such as cloud cover and sunshine duration data of Bangladesh Meteorological Department from 1992 to 2001 used for the estimation of global solar radiation as they are correlated. Technoeconomic feasibility analysis is done for 100 kW grid connected wind and solar photovoltaic (PV) systems. Renewable-energy-based system will bring more environmental benefits than conventional power in terms of human health, reduction of air pollution, and decrease of noise, and so forth. However, in the above estimation, these were not considered.

Report Details Solar Radiation Alert and Recommendations

Space Weather ◽  
2006 ◽  
Vol 4 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Tracy Staedter
Keyword(s):  
Solar Radiation
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