scholarly journals Hourly resolved cloud modification factors in the ultraviolet

2008 ◽  
Vol 8 (1) ◽  
pp. 181-214 ◽  
Author(s):  
H. Staiger ◽  
P. N. den Outer ◽  
A. F. Bais ◽  
U. Feister ◽  
B. Johnsen ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Uv Radiation ◽  
Rayleigh Scattering ◽  
Weather Prediction ◽  
Global Radiation ◽  
Action Spectrum ◽  
Solar Irradiation ◽  
Solar Disc ◽  
Global Irradiance ◽  
The Cost

Abstract. Cloud impacts on the transfer of Ultraviolet (UV) radiation through the atmosphere can be assessed using a cloud modification factor (CMF). The total global solar irradiation has proven to be a solid basis to derive CMF's for the UV radiation (UV_CMF). Total global irradiance is frequently measured and forecasted by numerical weather prediction systems. Its advantage compared to for instance cloud cover is that measured solar global irradiance contains already the effect of multiple reflection between cloud layers, reflection between the sides of the clouds, as well as the distinct difference whether the solar disc is obscured by clouds or not. In the UV range clouds decrease the irradiance to a lesser extent than in the visible and infrared spectral range; Rayleigh scattering in the atmosphere yields a larger fraction of scatter radiation compared to that of light and infrared, hence, obscuring the solar disc will not totally block out the irradiation. Thus the relationship between CMF's for solar radiation and for UV-radiation is not straight forwards, but will depend on e.g. the solar zenith angle (SZA) and wavelength band or action spectrum in the UV considered. Den Outer et al. (2005) provide a UV_CMF algorithm on a daily base accounting for these influences. It requires as input a daily CMF in total global radiation (SOL_CMF) and the SZA at noon. The calculation of SOL-CMF uses the clear sky algorithm of the European Solar Radiation Atlas to account for varying turbidity impacts. The algorithm's capability to derive hourly UV_CMF's based on the SZA at the corresponding hour and its worldwide applicability is validated using hourly resolved observational data retrieved from the databases of the COST-Action 726 on "Long term changes and climatology of UV radiation over Europe" and the USDA UV-B Monitoring and Research Program. The model performance for hourly resolution is shown to be comparable in absolute and relative deviations from a measured mean smoothed dependent on SZA with the well performing daily models of the COST-726 model intercomparison (Koepke et al., 2006).

scholarly journals Hourly resolved cloud modification factors in the ultraviolet

2008 ◽  
Vol 8 (9) ◽  
pp. 2493-2508 ◽  
Author(s):  
H. Staiger ◽  
P. N. den Outer ◽  
A. F. Bais ◽  
U. Feister ◽  
B. Johnsen ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Uv Radiation ◽  
Weather Prediction ◽  
Action Spectrum ◽  
Monitoring Program ◽  
Daily Basis ◽  
Solar Irradiation ◽  
Cloud Optical Depth ◽  
Clear Sky ◽  
The Cost

Abstract. Cloud impacts on the transfer of ultraviolet (UV) radiation through the atmosphere can be assessed by using a cloud modification factor (CMF). CMF, which is based on total global solar irradiation (SOLCMF), has proved to be a solid basis to derive CMFs for the UV radiation (UVCMF). This is an advantage, because total global irradiance, the basis for SOLCMF, is frequently measured and forecasted by numerical weather prediction systems and includes all relevant effects for radiation transmission, such as cloud optical depth, different cloud layers, multiple reflection, as well as the distinct difference as to whether the solar disc is obscured by clouds or not. In the UV range clouds decrease the irradiance to a lesser extent than in the visible and infrared spectral range. Thus the relationship between CMFs for solar radiation and for UV-radiation is not straight forward, but will depend on whether, for example, the solar zenith angle (SZA) and wavelength band or action spectrum in the UV have been taken into consideration. Den Outer et al. provide a UVCMF algorithm on a daily basis, which accounts for these influences. It requires as input a daily SOLCMF and the SZA at noon. The calculation of SOLCMF uses the clear-sky algorithm of the European Solar Radiation Atlas to account for varying turbidity impacts. The algorithm's capability to derive hourly UVCMFs based on the SZA at the corresponding hour and its worldwide applicability is validated for erythemal UV using observational data retrieved from the databases of the COST-Action 726 on "Long-term changes and climatology of UV radiation over Europe" and the USDA UV-B Monitoring Program. The clear-sky part of the models has proved to be of good quality. Accumulated to daily doses it forms a tight cluster of points to the highest measured daily sums. All sky model performances for hourly resolution are shown to be comparable in accuracy with the well performing daily models of the COST-726 model intercomparison.

scholarly journals Simulation and design of collector array units within large systems

2019 ◽  
Author(s):  
Jianhua Fan ◽  
Zhiyong Tian ◽  
Simon Furbo ◽  
Weiqiang Kong ◽  
Daniel Tschopp
Keyword(s):  
Solar Radiation ◽  
Thermal Performance ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Solar Heating ◽  
Heating Systems ◽  
Global Irradiance ◽  
Radiation Data ◽  
Large Systems ◽  
Beam Component

Solar radiation data is necessary for the design of solar heating systems and used to estimate the thermal performance of solar heating plants. Compared to global irradiance, the direct beam component shows much more variability in space and time. The global radiation split into beam and diffuse radiation on collector plane is important for the evaluation of the performance of different collector types and collector field designs.

scholarly journals Skill of Direct Solar Radiation Predicted by the ECMWF Global Atmospheric Model over Australia

2014 ◽  
Vol 53 (11) ◽  
pp. 2571-2588 ◽  
Author(s):  
Alberto Troccoli ◽  
Jean-Jacques Morcrette
Keyword(s):  
Solar Radiation ◽  
Power Plants ◽  
Solar Power ◽  
Weather Prediction ◽  
Global Radiation ◽  
Atmospheric Model ◽  
Direct Solar Radiation ◽  
Efficient Production ◽  
Clear Sky ◽  
Sky Conditions

AbstractPrediction of direct solar radiation is key in sectors such as solar power and agriculture; for instance, it can enable more efficient production of energy from concentrating solar power plants. An assessment of the quality of the direct solar radiation forecast by two versions of the European Centre for Medium-Range Weather Forecasts (ECMWF) global numerical weather prediction model up to 5 days ahead is carried out here. The performance of the model is measured against observations from four solar monitoring stations over Australia, characterized by diverse geographic and climatic features, for the year 2006. As a reference, the performance of global radiation forecast is carried out as well. In terms of direct solar radiation, while the skill of the two model versions is very similar, and with relative mean absolute errors (rMAEs) ranging from 18% to 45% and correlations between 0.85 and 0.25 at around midday, their performance is substantially enhanced via a simple postprocessing bias-correction procedure. There is a marked dependency on cloudy conditions, with rMAEs 2–4 times as large for very cloudy-to-overcast conditions relative to clear-sky conditions. There is also a distinct dependency on the background climatic clear-sky conditions of the location considered. Tests made on a simulated operational setup targeting three quantiles show that direct radiation forecasts achieve potentially high scores. Overall, these analyses provide an indication of the potential practical use of direct irradiance forecast for applications such as solar power operations.

scholarly journals Solar UV-B/A radiation is highly effective in inactivating SARS-CoV-2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabrizio Nicastro ◽  
Giorgia Sironi ◽  
Elio Antonello ◽  
Andrea Bianco ◽  
Mara Biasin ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Open Space ◽  
Uv Light ◽  
Rna Virus ◽  
Action Spectrum ◽  
Solar Irradiation ◽  
Mortality Data ◽  
Solar Uv ◽  
Solar Pump ◽  
Set Up

AbstractSolar UV-C photons do not reach Earth’s surface, but are known to be endowed with germicidal properties that are also effective on viruses. The effect of softer UV-B and UV-A photons, which copiously reach the Earth’s surface, on viruses are instead little studied, particularly on single-stranded RNA viruses. Here we combine our measurements of the action spectrum of Covid-19 in response to UV light, Solar irradiation measurements on Earth during the SARS-CoV-2 pandemics, worldwide recorded Covid-19 mortality data and our “Solar-Pump” diffusive model of epidemics to show that (a) UV-B/A photons have a powerful virucidal effect on the single-stranded RNA virus Covid-19 and that (b) the Solar radiation that reaches temperate regions of the Earth at noon during summers, is sufficient to inactivate 63% of virions in open-space concentrations (1.5 × 103 TCID50/mL, higher than typical aerosol) in less than 2 min. We conclude that the characteristic seasonality imprint displayed world-wide by the SARS-Cov-2 mortality time-series throughout the diffusion of the outbreak (with temperate regions showing clear seasonal trends and equatorial regions suffering, on average, a systematically lower mortality), might have been efficiently set by the different intensity of UV-B/A Solar radiation hitting different Earth’s locations at different times of the year. Our results suggest that Solar UV-B/A play an important role in planning strategies of confinement of the epidemics, which should be worked out and set up during spring/summer months and fully implemented during low-solar-irradiation periods.

scholarly journals Estimation of Global Solar Radiation in Mubi, Nigeria

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Ogbaka D.T ◽  
Bassi H ◽  
Lami D.S ◽  
Tahir M.A
Keyword(s):  
Solar Radiation ◽  
Global Radiation ◽  
Energy System ◽  
Global Solar Radiation ◽  
Solar Irradiation ◽  
Ann Model ◽  
Acceptable Error ◽  
Solar Radiation Intensity ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

Application of solar energy system requires having knowledge about solar irradiation potential in different locations. This study therefore used artificial neural networks for predicting solar global radiation by using metrological data. There is no report about prediction of solar radiation potential for Mubi by using Artificial Neural Network (ANN) method. It is very encouraging to observe a very fine agreement between the measured and estimated values shown in study. The ANN Model is considered the best relation for estimating the global solar radiation intensity for Mubi region with an acceptable error. The MSE, RMSE, MBE, MABE and MAPE values are 0.930, 0.964, 0.3358 MJm−2day−1, 0.8175 MJm−2day−1 and 19.30%, respectively. The ANN models appear auspicious for estimating the Global Solar Radiation in the locations where there are no solar radiation measurement stations.

scholarly journals Relation between Global Solar Radiation and Solar Ultraviolet Radiation in Different Parts of Nepal

1970 ◽  
Vol 8 (3) ◽  
pp. 169-175
Author(s):  
Rudra P Pokhrel ◽  
Binod K Bhattarai
Keyword(s):  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Public Awareness ◽  
Global Radiation ◽  
Global Solar Radiation ◽  
Regression Equations ◽  
Solar Ultraviolet Radiation ◽  
Radiation Level ◽  
Solar Ultraviolet

Part of the solar spectrum whose wavelength lies between 40 to 400 nm is called Solar Ultraviolet radiation. Solar UV Index (UVI) is the measure of the UV radiation level at a place, which plays the important role to raise public awareness and alert people to use protective measures when exposed to UV radiation. This study tries to find out the UV radiation level at a place by knowing the global radiation and will help to find out the UV radiation level at different places where UV radiation measuring instruments are not easily accessible. By the study of the relationship between global solar radiation and Solar Ultraviolet radiation at different sites (Biratnagar, Lukla, Kathmandu and Pokhara) of Nepal, simple regression equations were obtained. UV radiation level at a place was retrieved by using this equation. Ground based global solar radiation were measured by using radiation measuring instrument, Pyranometer (CMP6), manufactured by Kipp and Zonen, Netherland. A comparison between equation based calculation and ground based measurement of UV level (using NLU-UV meter) shows the average deviation of 3% at Lukla, 7% at Kathmandu and Pokhara and 6% Biratnagar in the year 2009 and 2010. It is also noted that Lukla is clearer among the four stations. This deviation might be due to effect of aerosols, humidity and non-ideal cosine response of the instrument. DOI: http://dx.doi.org/10.3126/jie.v8i3.5942 JIE 2011; 8(3): 169-175

scholarly journals Effects of solar radiation on collagen-based biomaterials

2006 ◽  
Vol 2006 ◽  
pp. 1-6 ◽  
Author(s):  
Alina Sionkowska ◽  
Marcin Wisniewski ◽  
Joanna Skopinska ◽  
Diego Mantovani
Keyword(s):  
Thin Films ◽  
Solar Radiation ◽  
Uv Radiation ◽  
Synthetic Polymer ◽  
Vinyl Pyrrolidone ◽  
Solar Irradiation ◽  
Poly Vinyl Alcohol ◽  
Solar Uv ◽  
Poly Vinyl Pyrrolidone ◽  
Artificial Uv

The effect of solar radiation on collagen and collagen/synthetic polymer blends in the form of thin films and solutions has been studied by UV-VIS and FTIR spectroscopies. Films and solutions of collagen blended with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) were irradiated by solar light. It was found that UV-VIS spectra, which characterize collagen, collagen/PVA, and collagen/PVP blended films, were significantly altered by solar radiation. FTIR spectra of collagen, collagen/PVA, and collagen/PVP films showed that after solar irradiation, the positions of Amide A bands were shifted to lower wavenumbers. There was not any significant alteration in the position of Amide I and Amide II bands of collagen and its blends after solar radiation. The effect of solar UV radiation in comparison with artificial UV radiation has been discussed.

scholarly journals Analysis and Optimization of a Novel Hexagonal Waveguide Concentrator for Solar Thermal Applications

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2146
Author(s):  
Karunesh Kant ◽  
Karthik Nithyanandam ◽  
Ranga Pitchumani
Keyword(s):  
Industrial Process ◽  
Cost Effective ◽  
Solar Irradiation ◽  
Maintenance Cost ◽  
Solar Concentrator ◽  
Thermal Desalination ◽  
Process Heat ◽  
Solar Thermal Applications ◽  
The Cost ◽  
Operation And Maintenance Cost

This paper analyzes a novel, cost-effective planar waveguide solar concentrator design that is inspired by cellular hexagonal structures in nature with the benefits of facile installation and low operation and maintenance cost. A coupled thermal and optical analysis of solar irradiation through an ideal hexagonal waveguide concentrator integrated with a linear receiver is presented, along with a cost analysis methodology, to establish the upper limit of performance. The techno-economic model, coupled with numerical optimization, is used to determine designs that maximized power density and minimized the cost of heat in the temperature range of 100–250 °C, which constitutes more than half of the industrial process heat demand. Depending on the incident solar irradiation and the application temperature, the cost of heat for the optimal design configuration ranged between 0.1–0.27 $/W and 0.075–0.18 $/W for waveguide made of ZK7 glass and polycarbonate, respectively. A techno-economic analysis showed the potential of the technology to achieve cost as low as 80 $/m2 and 61 $/m2 for waveguide made of ZK7 glass and polycarbonate material, respectively, which is less than half the cost of state-of-the-art parabolic trough concentrators. Overall, the hexagonal waveguide solar concentrator technology shows immense potential for decarbonizing the industrial process heat and thermal desalination sectors.

scholarly journals Calibration and Validation of ArcGIS Solar Radiation Tool for Photovoltaic Potential Determination in the Netherlands

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1865
Author(s):  
Bala Bhavya Kausika ◽  
Wilfried G. J. H. M. van Sark
Keyword(s):  
Solar Radiation ◽  
The Netherlands ◽  
Urban Areas ◽  
Input Data ◽  
Solar Irradiation ◽  
Energy Yield ◽  
Atmospheric Parameters ◽  
Factors Affecting ◽  
Calibration And Validation ◽  
Solar Radiation Model

Geographic information system (GIS) based tools have become popular for solar photovoltaic (PV) potential estimations, especially in urban areas. There are readily available tools for the mapping and estimation of solar irradiation that give results with the click of a button. Although these tools capture the complexities of the urban environment, they often miss the more important atmospheric parameters that determine the irradiation and potential estimations. Therefore, validation of these models is necessary for accurate potential energy yield and capacity estimations. This paper demonstrates the calibration and validation of the solar radiation model developed by Fu and Rich, employed within ArcGIS, with a focus on the input atmospheric parameters, diffusivity and transmissivity for the Netherlands. In addition, factors affecting the model’s performance with respect to the resolution of the input data were studied. Data were calibrated using ground measurements from Royal Netherlands Meteorological Institute (KNMI) stations in the Netherlands and validated with the station data from Cabauw. The results show that the default model values of diffusivity and transmissivity lead to substantial underestimation or overestimation of solar insolation. In addition, this paper also shows that calibration can be performed at different time scales depending on the purpose and spatial resolution of the input data.

scholarly journals Atmospheric influences on infrared-laser signals used for occultation measurements between Low Earth Orbit satellites

2011 ◽  
Vol 4 (10) ◽  
pp. 2273-2292 ◽  
Author(s):  
S. Schweitzer ◽  
G. Kirchengast ◽  
V. Proschek
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Thermal Radiation ◽  
Rayleigh Scattering ◽  
Infrared Laser ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Wind Speed Profile ◽  
Upper Troposphere ◽  
Trace Species

Abstract. LEO-LEO infrared-laser occultation (LIO) is a new occultation technique between Low Earth Orbit (LEO) satellites, which applies signals in the short wave infrared spectral range (SWIR) within 2 μm to 2.5 μm. It is part of the LEO-LEO microwave and infrared-laser occultation (LMIO) method that enables to retrieve thermodynamic profiles (pressure, temperature, humidity) and altitude levels from microwave signals and profiles of greenhouse gases and further variables such as line-of-sight wind speed from simultaneously measured LIO signals. Due to the novelty of the LMIO method, detailed knowledge of atmospheric influences on LIO signals and of their suitability for accurate trace species retrieval did not yet exist. Here we discuss these influences, assessing effects from refraction, trace species absorption, aerosol extinction and Rayleigh scattering in detail, and addressing clouds, turbulence, wind, scattered solar radiation and terrestrial thermal radiation as well. We show that the influence of refractive defocusing, foreign species absorption, aerosols and turbulence is observable, but can be rendered small to negligible by use of the differential transmission principle with a close frequency spacing of LIO absorption and reference signals within 0.5%. The influences of Rayleigh scattering and terrestrial thermal radiation are found negligible. Cloud-scattered solar radiation can be observable under bright-day conditions, but this influence can be made negligible by a close time spacing (within 5 ms) of interleaved laser-pulse and background signals. Cloud extinction loss generally blocks SWIR signals, except very thin or sub-visible cirrus clouds, which can be addressed by retrieving a cloud layering profile and exploiting it in the trace species retrieval. Wind can have a small influence on the trace species absorption, which can be made negligible by using a simultaneously retrieved or a moderately accurate background wind speed profile. We conclude that the set of SWIR channels proposed for implementing the LMIO method (Kirchengast and Schweitzer, 2011) provides adequate sensitivity to accurately retrieve eight trace species of key importance to climate and atmospheric chemistry (H2O, CO2, 13CO2, C18OO, CH4, N2O, O3, CO) in the upper troposphere/lower stratosphere region outside clouds under all atmospheric conditions. Two further species (HDO, H218O) can be retrieved in the upper troposphere.

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