scholarly journals Predicting solar radiation using a parametric cloud model

2020 ◽  
Vol 172 ◽  
pp. 11006
Author(s):  
Kristian Skeie ◽  
Arild Gustavsen
Keyword(s):  
Solar Radiation ◽  
Cloud Model ◽  
Weather Prediction ◽  
Global Solar Radiation ◽  
Vertical Surface ◽  
Original Method ◽  
Surface Radiation ◽  
Cloud Coverage ◽  
Forecasting Performance ◽  
Nwp Model

In this paper, we evaluate a method to calculate hourly global solar radiation and improve the calculation of diffuse and vertical surface radiation on building facades by accounting for ground conditions based on publicly available data of cloud coverage, temperature and precipitation from a forecast service covering the Nordic countries. The detailed weather forecasts produced by MET Norway provide hourly forecasts for the next 60 hours, and 6-hour predictions for the next week. To calculate solar radiation on cloudy days the clear and cloudy sky MAC model developed by Davies and Mckay (1982) is used. Instead of basing the prediction on ground observations as in the original method, cloud coverage in three levels and total cloud cover is used as input in a cloud product parameterisation. The resulting global horizontal irradiance is validated against the output of the numerical weather prediction (NWP) model and compared to a year of hourly ground measurements in Trondheim, Norway. To evaluate applicability to the building sciences, vertical irradiance measurements are compared to tilted surface irradiance calculated with the ISO 52010:2017 method. For the location, six-hour forecasting performance is on par with the GHI output of the NWP model (using the cloud layer model and the available weather parameters of the location forecast API). To account for the unpredictability of clouds and improve the short-term forecasting performance beyond 38 % RMSD, 38 % SD and 0.80 R2 a different approach is needed, like combining model and sky observations.

scholarly journals Compatibility of different measurement techniques. Long-term global solar radiation observations at Izaña Observatory

2016 ◽  
Author(s):  
Rosa Delia García ◽  
Emilio Cuevas ◽  
Omaira Elena García ◽  
Ramon Ramón ◽  
Pedro Miguel Romero-Campos ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Sunshine Duration ◽  
Measurement Techniques ◽  
Temporal Stability ◽  
Global Solar Radiation ◽  
Surface Radiation ◽  
Multifilter Rotating Shadowband Radiometer ◽  
High Consistency

Abstract. A 1-year intercomparison of classical and modern radiation and sunshine duration instruments has been performed at Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain) starting on July 17, 2014. We compare global solar radiation (GSR) records measured with a CM-21 pyranometer Kipp & Zonen, taken in the framework of the Baseline Surface Radiation Network, with those measured with a Multifilter Rotating Shadowband Radiometer (MFRSR), and a bimetallic pyranometer (PYR), and GSR estimated from sunshine duration performed by a Campbell-Stokes sunshine recorder (CS) and a Kipp & Zonen sunshine duration sensor (CSD). Given the GSR BSRN records are subject of strict quality controls (based on principles of physical limits and comparison with the LibRadtran model), they have been used as reference in the intercomparison study. We obtain an overall root mean square error (RMSE) of ~0.9 MJm2 (4 %) for GSR PYR and GSR MFRSR, 1.9 MJm2 (7 %) and 1.2 MJm2 (5 %) for GSR CS and GSR CSD, respectively. Factors such as temperature, fraction of the clear sky, relative humidity and the solar zenith angle have shown to moderately affect the GSR observations. As application of the methodology developed in this work, we have re-evaluated the GSR time series between 1977 and 1991 obtained with two PYRs at IZO. By comparing with coincident GSR estimates from SD observations, we probe the high consistency of those measurements and their temporal stability. These results demonstrate that 1) the continuous-basis intercomparison of different GSR techniques offers important diagnostics for identifying inconsistencies between GSR data records, and 2) the GSR measurements performed with classical and more simple instruments are consistent with more modern techniques and, thus, valid to recover GSR time series and complete worldwide distributed GSR data. The intercomparison and quality assessment of these different techniques have allowed to obtain a complete and consistent long-term global solar radiation series (1977–2015) at Izaña.

scholarly journals Implementation of Bessel's method for solar eclipses prediction in the WRF-ARW model

2016 ◽  
Vol 16 (9) ◽  
pp. 5949-5967 ◽  
Author(s):  
Alex Montornès ◽  
Bernat Codina ◽  
John W. Zack ◽  
Yolanda Sola
Keyword(s):  
Solar Radiation ◽  
Solar Eclipse ◽  
Weather Prediction ◽  
Grid Point ◽  
Absolute Error ◽  
Resource Assessment ◽  
Surface Radiation ◽  
Computational Time ◽  
Arw Model ◽  
Solar Eclipses

Abstract. Solar eclipses are predictable astronomical events that abruptly reduce the incoming solar radiation into the Earth's atmosphere, which frequently results in non-negligible changes in meteorological fields. The meteorological impacts of these events have been analyzed in many studies since the late 1960s. The recent growth in the solar energy industry has greatly increased the interest in providing more detail in the modeling of solar radiation variations in numerical weather prediction (NWP) models for the use in solar resource assessment and forecasting applications. The significant impact of the recent partial and total solar eclipses that occurred in the USA (23 October 2014) and Europe (20 March 2015) on solar power generation have provided additional motivation and interest for including these astronomical events in the current solar parameterizations.Although some studies added solar eclipse episodes within NWP codes in the 1990s and 2000s, they used eclipse parameterizations designed for a particular case study. In contrast to these earlier implementations, this paper documents a new package for the Weather Research and Forecasting–Advanced Research WRF (WRF-ARW) model that can simulate any partial, total or hybrid solar eclipse for the period 1950 to 2050 and is also extensible to a longer period. The algorithm analytically computes the trajectory of the Moon's shadow and the degree of obscuration of the solar disk at each grid point of the domain based on Bessel's method and the Five Millennium Catalog of Solar Eclipses provided by NASA, with a negligible computational time. Then, the incoming radiation is modified accordingly at each grid point of the domain.This contribution is divided in three parts. First, the implementation of Bessel's method is validated for solar eclipses in the period 1950–2050, by comparing the shadow trajectory with values provided by NASA. Latitude and longitude are determined with a bias lower than 5  ×  10−3 degrees (i.e.,  ∼  550 m at the Equator) and are slightly overestimated and underestimated, respectively. The second part includes a validation of the simulated global horizontal irradiance (GHI) for four total solar eclipses with measurements from the Baseline Surface Radiation Network (BSRN). The results show an improvement in mean absolute error (MAE) from 77 to 90 % under cloudless skies. Lower agreement between modeled and measured GHI is observed under cloudy conditions because the effect of clouds is not included in the simulations for a better analysis of the eclipse outcomes. Finally, an introductory discussion of eclipse-induced perturbations in the surface meteorological fields (e.g., temperature, wind speed) is provided by comparing the WRF–eclipse outcomes with control simulations.

scholarly journals Producing Global Solar Radiation maps in Iraq Using Geographic Information Systems

2018 ◽  
Vol 226 (1) ◽  
pp. 41-48
Author(s):  
Hussain Zaydan Ali ◽  
Ghusoon Idan Arb ◽  
Ziena Jameel yusif
Keyword(s):  
Solar Radiation ◽  
Spherical Model ◽  
Energy System ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Surface Radiation ◽  
Kriging Interpolation ◽  
Radiation Data ◽  
Circular Model ◽  
Climatic Information

The design and operation of any solar energy system requires a good knowledge of the solar radiation data in a location. This data finds application in agriculture, climatology, meteorology, etc. Since the solar radiation reaching the earth’s surface varies with climatic conditions of a place, a study of solar radiation under local climatic condition is essential. Global solar radiation is of economic importance as renewable energy alternatives. In this research 14 Iraqi climatic stations radiation data were used for the years 2013 to 2015.  Data have been designed and calculated by using Excel.  ArcGIS 10.2 is used for spatial interpolation and mapping activities. Surface radiation map have been generated by using ordinary kriging interpolation technique. Different models are tested, namely Spherical, Gaussian and Circular model. Creation of digital grid maps makes it possible to obtain climatic information at any point, whether there is a weather station or not. Results show that the spherical model outperforms Gaussian and circular models.                                      

scholarly journals The HIRLAM fast radiation scheme for mesoscale numerical weather prediction models

2017 ◽  
Vol 14 ◽  
pp. 195-215 ◽  
Author(s):  
Laura Rontu ◽  
Emily Gleeson ◽  
Petri Räisänen ◽  
Kristian Pagh Nielsen ◽  
Hannu Savijärvi ◽  
...  
Keyword(s):  
Numerical Weather Prediction ◽  
Prediction Models ◽  
Weather Prediction ◽  
Surface Fluxes ◽  
Surface Radiation ◽  
Numerical Weather ◽  
Clear Sky ◽  
Radiation Output ◽  
Dry Conditions ◽  
Nwp Model

Abstract. This paper provides an overview of the HLRADIA shortwave (SW) and longwave (LW) broadband radiation schemes used in the HIRLAM numerical weather prediction (NWP) model and available in the HARMONIE-AROME mesoscale NWP model. The advantage of broadband, over spectral, schemes is that they can be called more frequently within the model, without compromising on computational efficiency. In mesoscale models fast interactions between clouds and radiation and the surface and radiation can be of greater importance than accounting for the spectral details of clear-sky radiation; thus calling the routines more frequently can be of greater benefit than the deterioration due to loss of spectral details. Fast but physically based radiation parametrizations are expected to be valuable for high-resolution ensemble forecasting, because as well as the speed of their execution, they may provide realistic physical perturbations. Results from single-column diagnostic experiments based on CIRC benchmark cases and an evaluation of 10 years of radiation output from the FMI operational archive of HIRLAM forecasts indicate that HLRADIA performs sufficiently well with respect to the clear-sky downwelling SW and longwave LW fluxes at the surface. In general, HLRADIA tends to overestimate surface fluxes, with the exception of LW fluxes under cold and dry conditions. The most obvious overestimation of the surface SW flux was seen in the cloudy cases in the 10-year comparison; this bias may be related to using a cloud inhomogeneity correction, which was too large. According to the CIRC comparisons, the outgoing LW and SW fluxes at the top of atmosphere are mostly overestimated by HLRADIA and the net LW flux is underestimated above clouds. The absorption of SW radiation by the atmosphere seems to be underestimated and LW absorption seems to be overestimated. Despite these issues, the overall results are satisfying and work on the improvement of HLRADIA for the use in HARMONIE-AROME NWP system is ongoing. In a HARMONIE-AROME 3-D forecast experiment we have shown that the frequency of the call for the radiation parametrization and choice of the parametrization scheme makes a difference to the surface radiation fluxes and changes the spatial distribution of the vertically integrated cloud cover and precipitation.

scholarly journals Implementation of the Bessel's method for solar eclipses prediction in the WRF-ARW model

2016 ◽  
Author(s):  
A. Montornès ◽  
B. Codina ◽  
J. W. Zack ◽  
Y. Sola
Keyword(s):  
Solar Radiation ◽  
Solar Eclipse ◽  
Weather Prediction ◽  
Grid Point ◽  
Measurement Data ◽  
Surface Radiation ◽  
Computational Time ◽  
Arw Model ◽  
Solar Eclipses ◽  
The Impact

Abstract. Solar eclipses are predictable astronomical events that abruptly reduce the incoming solar radiation into the Earth's atmosphere, which frequently result in non-negligible changes in meteorological fields. The meteorological impacts of these events have been analyzed in many studies since the late 1960s. The recent growth in the solar energy industry has greatly increased the interest in adding additional detail to the modeling of solar radiation variations in Numerical Weather Prediction (NWP) models for use in solar resource assessment and forecasting applications. The recent partial and total solar eclipses that occurred in USA (October 23, 2014) and Europe (March 20, 2015), respectively, are showing the necessity for including these astronomical events on the current solar parameterizations, beyond the purely meteorological interest. Although some studies added solar eclipse episodes within NWP codes in the 1990s and 2000s, they used eclipse parameterizations designed for a particular case of study. In contrast to these earlier implementations, this paper documents a new package for the Weather Research and Forecasting – Advanced Research (WRF-ARW) model that can simulate any partial, total or hybrid solar eclipse for the period 1950 to 2050 and is also extensible to a longer period. The algorithm computes analytically the trajectory of the Moon's shadow and the degree of obscuration of the solar disk at each grid-point of the domain based on the Bessel's method and the Five Millennium Catalog of Solar Eclipses provided by NASA, with a negligible computational time. Then, the incoming radiation is modified accordingly at each grid-point of the domain. This contribution is divided in two parts. First, we present a description of the implementation of the Bessel's method within the WRF-ARW model together with a validation for the period 1950-2050 of all solar eclipse trajectories with respect to NASA values. Second, we analyze the model response in four total solar eclipse episodes: 1994-11-03 (South America), 1999-08-11 (Europe), 2006-03-29 (North Africa) and 2009-07-22 (Eastern Asia). The second part includes a validation of the simulated global horizontal irradiance (GHI) with measurement data from selected Baseline Surface Radiation Network sites within the area affected by each event as well as an analysis of the impact of the GHI changes in surface temperature and wind speed.

scholarly journals Producing Global Solar Radiation maps in Iraq Using Geographic Information Systems

2018 ◽  
pp. 41-48
Author(s):  
Hussain Zaydan Ali ◽  
Ghusoon Idan Arb ◽  
Ziena Jameel yusif
Keyword(s):  
Solar Radiation ◽  
Spherical Model ◽  
Energy System ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Surface Radiation ◽  
Kriging Interpolation ◽  
Radiation Data ◽  
Circular Model ◽  
Climatic Information

The design and operation of any solar energy system requires a good knowledge of the solar radiation data in a location. This data finds application in agriculture, climatology, meteorology, etc. Since the solar radiation reaching the earth’s surface varies with climatic conditions of a place, a study of solar radiation under local climatic condition is essential. Global solar radiation is of economic importance as renewable energy alternatives. In this research 14 Iraqi climatic stations radiation data were used for the years 2013 to 2015.  Data have been designed and calculated by using Excel.  ArcGIS 10.2 is used for spatial interpolation and mapping activities. Surface radiation map have been generated by using ordinary kriging interpolation technique. Different models are tested, namely Spherical, Gaussian and Circular model. Creation of digital grid maps makes it possible to obtain climatic information at any point, whether there is a weather station or not. Results show that the spherical model outperforms Gaussian and circular models.                                      

scholarly journals Diffuse solar radiation and associated meteorological parameters in India

1996 ◽  
Vol 14 (10) ◽  
pp. 1051-1059 ◽  
Author(s):  
A. B. Bhattacharya ◽  
S. K. Kar ◽  
R. Bhattacharya
Keyword(s):  
Solar Radiation ◽  
Meteorological Parameters ◽  
Global Radiation ◽  
Low Frequency ◽  
Diffuse Radiation ◽  
Global Solar Radiation ◽  
Surface Radiation ◽  
Diffuse Solar Radiation ◽  
Sunshine Hours ◽  
The Tropics

Abstract. Solar diffuse radiation data including global radiation, shortwave and longwave balances, net radiation and sunshine hours have been extensively analyzed to study the variation of diffuse radiation with turbidity and cloud discharges appearing in the form of atmospherics over the tropics. Results of surface radiation measurements at Calcutta, Poona, Delhi and Madras are presented together with some meteorological parameters. The monthly values of diffuse radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis in relation to the noise level of atmospherics at Calcutta in the very low frequency band. The results exhibit some definite seasonal changes which appear to be in close agreement with one another.

scholarly journals Comparison of radiation parametrizations within the HARMONIE–AROME NWP model

2018 ◽  
Vol 15 ◽  
pp. 81-90 ◽  
Author(s):  
Laura Rontu ◽  
Anders V. Lindfors
Keyword(s):  
Weather Prediction ◽  
Global Radiation ◽  
Global Solar Radiation ◽  
Shortwave Radiation ◽  
Ensemble Prediction ◽  
Cloud Properties ◽  
Solar Radiation Flux ◽  
Prediction Systems ◽  
Nwp Model ◽  
Fine Resolution

Abstract. Downwelling shortwave radiation at the surface (SWDS, global solar radiation flux), given by three different parametrization schemes, was compared to observations in the HARMONIE–AROME numerical weather prediction (NWP) model experiments over Finland in spring 2017. Simulated fluxes agreed well with each other and with the observations in the clear-sky cases. In the cloudy-sky conditions, all schemes tended to underestimate SWDS at the daily level, as compared to the measurements. Large local and temporal differences between the model results and observations were seen, related to the variations and uncertainty of the predicted cloud properties. The results suggest a possibility to benefit from the use of different radiative transfer parametrizations in a NWP model to obtain perturbations for the fine-resolution ensemble prediction systems. In addition, we recommend usage of the global radiation observations for the standard validation of the NWP models.

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