Clear-Sky Radiation Models and Aerosol Effects

  • Christian A. GueymardEmail author
Part of the Green Energy and Technology book series (GREEN)


This chapter offers a description of the main factors that affect the transmission of solar radiation through the cloudless atmosphere, and the corresponding modeling approaches. The limitations of broadband modeling are discussed, and methodological improvements are described. A detailed discussion of the various inputs required by different clear-sky radiation models, and how to obtain such data, is provided so that the reader can operate these models with appropriate inputs, depending on the application and geographical coverage. In particular, the benefits of using atmospheric data provided by recent reanalyses are described. The impact of aerosol attenuation on the different irradiance components is discussed, with a focus on the aerosol optical depth. Its methods of measurement, properties, reduction methods, accuracy, and spatiotemporal variability are described. The error propagation between aerosol data and the predicted irradiance is quantified, and examples are provided. Seven models of the literature are selected for further discussion and validation. This validation is performed using high-quality radiometric data from Tamanrasset, Algeria, and is done in two different ways: an ideal validation based on the best possible (locally measured) aerosol information and a practical method (generalizable anywhere) based on reanalysis data. A sensible degradation of performance is obvious when using the second approach. Finally, some likely or desirable future developments in the field are described.



The AERONET and BSRN staff and participants are thanked for their successful effort in establishing and maintaining the various sites whose data were advantageously used in the present developments. The author also wishes to thank Dr. José Antonio Ruiz-Arias for his insightful comments and preparation of Fig. 4.


  1. Amillo AG, Huld T, Müller R (2014) A new database of global and direct solar radiation using the Eastern Meteosat satellite, models and validation. Remote Sens 6:8165–8189CrossRefGoogle Scholar
  2. Ångström A (1929) On the atmospheric transmission of sun radiation and on dust in the air. Geografis Annal 2:156–166Google Scholar
  3. Antonanzas-Torres F, Antonanzas J, Urraca R, Alia-Martinez M, Martinez-de-Pison FJ (2016) Impact of atmospheric components on solar clear-sky models at different elevation: case study Canary Islands. Energy Convers Manag 109:122–129CrossRefGoogle Scholar
  4. Badescu V (2013) Assessing the performance of solar radiation computing models and model selection procedures. J Atmos Sol-Terr Phys 105:119–134CrossRefGoogle Scholar
  5. Badescu V et al (2012a) Accuracy and sensitivity analysis for 54 models of computing hourly diffuse solar irradiation on clear sky. Theor Appl Climatol 111:379–399CrossRefGoogle Scholar
  6. Badescu V et al (2012b) Computing global and diffuse solar hourly irradiation on clear sky. Review and testing of 54 models. Renew Sust Energ Rev 16:1636–1656CrossRefGoogle Scholar
  7. Badescu V et al (2013) Accuracy analysis for fifty-four clear-sky solar radiation models using routine hourly global irradiance measurements in Romania. Renew Energy 55:85–103CrossRefGoogle Scholar
  8. Baig H, Fernández EF, Mallick TK (2016) Influence of spectrum and latitude on the annual optical performance of a dielectric based BICPV system. Sol Energy 124:268–277CrossRefGoogle Scholar
  9. Bird RE, Hulstrom RL (1980) Direct insolation models. Solar Energy Research Institute (now NREL) Rep. SERI/TR-335-344, Golden, CO.
  10. Bird RE, Hulstrom RL (1981a) Review, evaluation, and improvement of direct irradiance models. J Sol Energy Eng 103:182–192CrossRefGoogle Scholar
  11. Bird RE, Hulstrom RL (1981b) A simplified clear sky model for direct and diffuse insolation on horizontal surfaces. Solar Energy Research Institute (now NREL) Rep. SERI/TR-642–761, Golden, CO.
  12. Blanc P et al (2014) Direct normal irradiance related definitions and applications: the circumsolar issue. Sol Energy 110:561–577CrossRefGoogle Scholar
  13. Blanc P, Wald L (2016) On the effective solar zenith and azimuth angles to use with measurements of hourly irradiation. Adv Sci Res 13:1–6CrossRefGoogle Scholar
  14. Cachorro VE, Casanova JL, Frutos AMd (1987a) The influence of Angström parameters on calculated direct solar spectral irradiances at high turbidities. Sol Energy 39:399–407CrossRefGoogle Scholar
  15. Cachorro VE, de Frutos AM, Casanova JL (1987b) Determination of the Angström turbidity parameters. Appl Opt 26:3069–3076CrossRefGoogle Scholar
  16. Chauvin R, Nou J, Eynard J, Thil S, Grieu S (2018) A new approach to the real-time assessment and intraday forecasting of clear-sky direct normal irradiance. Sol Energy 167:35–51CrossRefGoogle Scholar
  17. Che H et al (2015) Ground-based aerosol climatology of China: aerosol optical depths from the China Aerosol Remote Sensing Network (CARSNET) 2002–2013. Atmos Chem Phys 15:7619–7652CrossRefGoogle Scholar
  18. d’Oliveira FA, de Melo FCL, Devezas TC (2016) High-altitude platforms—present situation and technology trends. J Aerosp Technol Manag 8:249–262CrossRefGoogle Scholar
  19. Eissa Y et al (2015) Validating surface downwelling solar irradiances estimated by the McClear model under cloud-free skies in the United Arab Emirates. Sol Energy 114:17–31CrossRefGoogle Scholar
  20. Eissa Y et al (2018) Prediction of the day-ahead clear-sky downwelling surface solar irradiances using the REST2 model and WRF-CHIMERE simulations over the Arabian Peninsula. Sol Energy 162:36–44CrossRefGoogle Scholar
  21. Engerer NA, Mills FP (2015) Validating nine clear sky radiation models in Australia. Sol Energy 120:9–24CrossRefGoogle Scholar
  22. Fernández EF, Almonacid F, Rodrigo P, Pérez-Higueras P (2013) Model for the prediction of the maximum power of a high concentrator photovoltaic module. Sol Energy 97:12–18CrossRefGoogle Scholar
  23. Gueymard CA (1989) A two-band model for the calculation of clear sky solar irradiance, illuminance, and photosynthetically active radiation at the Earth’s surface. Sol Energy 43:253–265CrossRefGoogle Scholar
  24. Gueymard CA (1994) Analysis of monthly average atmospheric precipitable water and turbidity in Canada and Northern United States. Sol Energy 53:57–71CrossRefGoogle Scholar
  25. Gueymard CA (1995) SMARTS2, simple model of the atmospheric radiative transfer of sunshine: algorithms and performance assessment. Florida Solar Energy Center, Cocoa, FL, Rep. FSEC-PF-270-95Google Scholar
  26. Gueymard CA (1996) Multilayer-weighted transmittance functions for use in broadband irradiance and turbidity calculations. In: Campbell-Howe R, Wilkins-Crowder B (eds) Proceeding of solar ‘96, American Solar Energy Society, Asheville, NC, pp 281–288Google Scholar
  27. Gueymard CA (1998) Turbidity determination from broadband irradiance measurements: a detailed multicoefficient approach. J Appl Meteorol 37:414–435CrossRefGoogle Scholar
  28. Gueymard CA (2001) Parameterized transmittance model for direct beam and circumsolar spectral irradiance. Sol Energy 71:325–346CrossRefGoogle Scholar
  29. Gueymard CA (2003a) Direct solar transmittance and irradiance predictions with broadband models. Pt 1: detailed theoretical performance assessment. Solar Energy 74:355–379. Corrigendum: Solar Energy 376, 513 (2004)Google Scholar
  30. Gueymard CA (2003b) Direct solar transmittance and irradiance predictions with broadband models. Pt 2: validation with high-quality measurements. Solar Energy 74:381–395. Corrigendum: Solar Energy 376, 515 (2004)Google Scholar
  31. Gueymard CA (2005) Interdisciplinary applications of a versatile spectral solar irradiance model: a review. Energy 30:1551–1576CrossRefGoogle Scholar
  32. Gueymard CA (2008a) Prediction and validation of cloudless shortwave solar spectra incident on horizontal, tilted, or tracking surfaces. Sol Energy 82:260–271CrossRefGoogle Scholar
  33. Gueymard CA (2008b) REST2: high-performance solar radiation model for cloudless-sky irradiance, illuminance, and photosynthetically active radiation—validation with a benchmark dataset. Sol Energy 82:272–285CrossRefGoogle Scholar
  34. Gueymard CA (2009) Direct and indirect uncertainties in the prediction of tilted irradiance for solar engineering applications. Sol Energy 83:432–444CrossRefGoogle Scholar
  35. Gueymard CA (2011) Uncertainties in modeled direct irradiance around the Sahara as affected by aerosols: are current datasets of bankable quality? J Sol Energy Eng 133:031013–031024CrossRefGoogle Scholar
  36. Gueymard CA (2012a) Clear-sky irradiance predictions for solar resource mapping and large-scale applications: improved validation methodology and detailed performance analysis of 18 broadband radiative models. Sol Energy 86:2145–2169CrossRefGoogle Scholar
  37. Gueymard CA (2012b) Temporal variability in direct and global irradiance at various time scales as affected by aerosols. Sol Energy 86:2553–3544Google Scholar
  38. Gueymard CA (2014a) Impact of on-site atmospheric water vapor estimation methods on the accuracy of local solar irradiance predictions. Sol Energy 101:74–82CrossRefGoogle Scholar
  39. Gueymard CA (2014b) A review of validation methodologies and statistical performance indicators for modeled solar radiation data: towards a better bankability of solar projects. Renew Sust Energ Rev 39:1024–1034CrossRefGoogle Scholar
  40. Gueymard CA (2017) Cloud and albedo enhancement impacts on solar irradiance using high-frequency measurements from thermopile and photodiode radiometers. Part 1: impacts on global horizontal irradiance. Sol Energy 153:755–765CrossRefGoogle Scholar
  41. Gueymard CA (2018) A reevaluation of the solar constant based on a 42-year total solar irradiance time series and a reconciliation of spaceborne observations. Sol Energy 168:2–9CrossRefGoogle Scholar
  42. Gueymard CA, Kambezidis HD (2004) Solar spectral radiation. In: Muneer T (ed) Solar radiation and daylight models. ElsevierGoogle Scholar
  43. Gueymard CA, Myers D, Emery K (2002) Proposed reference irradiance spectra for solar energy systems testing. Sol Energy 73:443–467CrossRefGoogle Scholar
  44. Gueymard CA, Myers DR (2008) Validation and ranking methodologies for solar radiation models. In: Badescu V (ed) Modeling solar radiation at the earth surface. SpringerGoogle Scholar
  45. Gueymard CA, Myers DR (2009) Evaluation of conventional and high-performance routine solar radiation measurements for improved solar resource, climatological trends, and radiative modeling. Sol Energy 83:171–185CrossRefGoogle Scholar
  46. Gueymard CA, Myers DR (2010) Solar resource for space and terrestrial applications. In: Fraas LM, Partain LD (eds) Solar cells and their applications, 2nd ed. WileyGoogle Scholar
  47. Gueymard CA, Ruiz-Arias JA (2015) Validation of direct normal irradiance predictions under arid conditions: a review of radiative models and their turbidity-dependent performance. Renew Sust Energ Rev 45:379–396CrossRefGoogle Scholar
  48. Gueymard CA, Thevenard D (2009) Monthly average clear-sky broadband irradiance database for worldwide solar heat gain and building cooling load calculations. Sol Energy 83:1998–2018CrossRefGoogle Scholar
  49. Gueymard CA, Vignola F (1998) Determination of atmospheric turbidity from the diffuse-beam broadband irradiance ratio. Sol Energy 63:135–146CrossRefGoogle Scholar
  50. Habte A, Sengupta M, Andreas A, Wilcox S, Stoffel T (2016) Intercomparison of 51 radiometers for determining global horizontal irradiance and direct normal irradiance measurements. Sol Energy 133:372–393CrossRefGoogle Scholar
  51. Holben BN et al (1998) AERONET—a federated instrument network and data archive for aerosol characterization. Remote Sens Environ 66:1–16CrossRefGoogle Scholar
  52. Holben BN et al (2001) An emerging ground-based aerosol climatology: aerosol optical depth from AERONET. J Geophys Res D106:12067–12097CrossRefGoogle Scholar
  53. Iacono MJ, Delamere JS, Mlawer EJ, Clough SA, Morcrette JJ, Hou YT (2004) Development and evaluation of RRTMG_SW, a shortwave radiative transfer model for general circulation model applications. In: Proceeding of 14th ARM science meeting, Albuquerque, NM.
  54. Ineichen P (2006) Comparison of eight clear sky broadband models against 16 independent data banks. Sol Energy 80:468–478CrossRefGoogle Scholar
  55. Ineichen P (2008) A broadband simplified version of the solis clear sky model. Sol Energy 82:758–762CrossRefGoogle Scholar
  56. Ineichen P (2016) Validation of models that estimate the clear sky global and beam solar irradiance. Sol Energy 132:332–344CrossRefGoogle Scholar
  57. Ineichen P (2018) High turbidity solis clear sky model: development and validation. Remote Sens 10:435CrossRefGoogle Scholar
  58. Inman RH, Edson JG, Coimbra CFM (2015) Impact of local broadband turbidity estimation on forecasting of clear sky direct normal irradiance. Sol Energy 117:125–138CrossRefGoogle Scholar
  59. Jessen W et al (2018) Proposal and evaluation of subordinate standard solar irradiance spectra for applications in solar energy systems. Sol Energy 168:30–43CrossRefGoogle Scholar
  60. Kosmopoulos PG, Kazadzis S, Taylor M, Raptis PI, Keramitsoglou I, Kiranoudis C, Bais AF (2018) Assessment of surface solar irradiance derived from real-time modelling techniques and verification with ground-based measurements. Atmos Meas Tech 11:907–924CrossRefGoogle Scholar
  61. Larrañeta M, Reno MJ, Lillo-Bravo I, Silva-Pérez MA (2017) Identifying periods of clear sky direct normal irradiance. Renew Energy 113:756–763CrossRefGoogle Scholar
  62. Lefèvre M et al (2013) McClear: a new model estimating downwelling solar radiation at ground level in clear-sky conditions. Atmos Meas Tech 6:2403–2418CrossRefGoogle Scholar
  63. Lefèvre M, Wald L (2016) Validation of the McClear clear-sky model in desert conditions with three stations in Israel. Adv Sci Res 13:21–26. Scholar
  64. Li J, Lv M, Sun K (2016) Optimum area of solar array for stratospheric solar-powered airship. Proc IMechE Part G J Aerospace Eng 231:2654–2665CrossRefGoogle Scholar
  65. Li ZQ et al (2018) Comprehensive study of optical, physical, chemical, and radiative properties of total columnar atmospheric aerosols over China: an overview of Sun–sky radiometer Observation Network (SONET) measurements. Bull Amer Meteorol Soc 99:739–755CrossRefGoogle Scholar
  66. Liu H, Aberle AG, Buonassisi T, Peters IM (2016) On the methodology of energy yield assessment for one-sun tandem solar cells. Sol Energy 135:598–604CrossRefGoogle Scholar
  67. Long CN, Ackerman TP (2000) Identification of clear skies from broadband pyranometer measurements and calculation of downwelling shortwave cloud effects. J Geophys Res 105D:15609–15626CrossRefGoogle Scholar
  68. Long CN, Shi Y (2008) An automated quality assessment and control algorithm for surface radiation measurements. Open Atmos Sci J 2:23–37CrossRefGoogle Scholar
  69. Martinez-Lozano JA, Utrillas MP, Tena F, Cachorro VE (1998) The parameterisation of the atmospheric aerosol optical depth using the Ångström power law. Sol Energy 63:303–311CrossRefGoogle Scholar
  70. Molineaux B, Ineichen P (1996) On the broad band transmittance of direct irradiance in a cloudless sky and its application to the parameterization of atmospheric turbidity. Sol Energy 56:553–563CrossRefGoogle Scholar
  71. Mueller RW et al (2004) Rethinking satellite-based solar irradiance modeling: the SOLIS clear-sky module. Remote Sens Environ 91:160–174CrossRefGoogle Scholar
  72. Oumbe A, Qu Z, Blanc P, Lefèvre M, Wald L, Cros S (2014) Decoupling the effects of clear atmosphere and clouds to simplify calculations of the broadband solar irradiance at ground level. Geosci Model Dev 7:1661–1669CrossRefGoogle Scholar
  73. Polo J, Alonso-Abella M, Ruiz-Arias JA, Balenzategui JL (2017) Worldwide analysis of spectral factors for seven photovoltaic technologies. Sol Energy 142:194–203CrossRefGoogle Scholar
  74. Polo J, Antonanzas-Torres F, Vindel JM, Ramirez L (2014) Sensitivity of satellite-based methods for deriving solar radiation to different choice of aerosol input and models. Renew Energy 68:785–792CrossRefGoogle Scholar
  75. Polo J, Estalayo G (2015) Impact of atmospheric aerosol loads on concentrating solar power production in arid-desert sites. Sol Energy 115:621–631CrossRefGoogle Scholar
  76. Reno MJ, Hansen CW (2016) Identification of periods of clear sky irradiance in time series of GHI measurements. Renew Energy 90:520–531CrossRefGoogle Scholar
  77. Rigollier C, Bauer O, Wald L (2000) On the clear sky model of the ESRA—European Solar Radiation Atlas—with respect to the Heliosat method. Sol Energy 68:33–48CrossRefGoogle Scholar
  78. Ruiz-Arias JA, Gueymard CA (2015) Solar resource for high-concentrator photovoltaic applications. In: Perez-Higueras PJ, Fernandez FE (eds) High concentrator photovoltaics: fundamentals, engineering and power plants. SpringerGoogle Scholar
  79. Ruiz-Arias JA, Gueymard CA (2018a) A multi-model benchmarking of direct and global clear-sky solar irradiance predictions at arid sites using a reference physical radiative transfer model. Sol Energy 171:447–465CrossRefGoogle Scholar
  80. Ruiz-Arias JA, Gueymard CA (2018b) Worldwide inter-comparison of clear-sky solar radiation models: consensus-based review of direct and global irradiance components simulated at the earth surface. Sol Energy 168:10–29CrossRefGoogle Scholar
  81. Ruiz-Arias JA, Gueymard CA, Quesada-Ruiz S, Santos-Alamillos FJ, Pozo-Vázquez D (2016) Bias induced by the AOD representation time scale in long-term solar radiation calculations. Part 1: sensitivity of the AOD distribution to the representation time scale. Sol Energy 137:608–620CrossRefGoogle Scholar
  82. Sengupta M, Habte A, Gueymard C, Wilbert S, Renné D (2017) Best practices handbook for the collection and use of solar resource data for solar energy applications, 2nd edn. National Renewable Energy Lab., Golden, CO. Rep. NREL/TP-5D00-68886,
  83. Sengupta M, Xie Y, Lopez A, Habte A, Maclaurin G, Shelby J (2018) The National Solar Radiation Data Base (NSRDB). Renew Sust Energ Rev 89:51–60CrossRefGoogle Scholar
  84. Sun Q, Wang Z, Li Z, Erb A, Schaaf CB (2017) Evaluation of the global MODIS 30 arc-second spatially and temporally complete snow-free land surface albedo and reflectance anisotropy dataset. Int J Appl Earth Obs Geoinf 58:36–49CrossRefGoogle Scholar
  85. Theristis M, O’Donovan TS (2015) Electrical-thermal analysis of III–V triple-junction solar cells under variable spectra and ambient temperatures. Sol Energy 118:533–546CrossRefGoogle Scholar
  86. Vignola F, Grover C, Lemon N, McMahan A (2012) Building a bankable solar radiation dataset. Sol Energy 86:2218–2229CrossRefGoogle Scholar
  87. Xie Y, Sengupta M, Dudhia J (2016) A Fast All-sky Radiation Model for Solar applications (FARMS): algorithm and performance evaluation. Sol Energy 135:435–445CrossRefGoogle Scholar
  88. Xie Y, Sengupta M, Deline C (2017) Recent advancements in the numerical simulation of surface irradiance for solar energy applications. In: Proceeding of IEEE 44th photovoltaic specialists conference, Washington, DC.
  89. Yang D (2016) Solar radiation on inclined surfaces: corrections and benchmarks. Sol Energy 136:288–302CrossRefGoogle Scholar
  90. Zhang H, Huang C, Yu S, Li L, Xin X, Liu Q (2018) A lookup-table-based approach to estimating surface solar irradiance from geostationary and polar-orbiting satellite data. Remote Sens 10:411CrossRefGoogle Scholar
  91. Zhang H, Zhang M, Cui Z, Wang Y, Xin J (2012) Simulation and validation of the aerosol optical thickness over China in 2006. Acta Meteorologica Sinica 26:330–344CrossRefGoogle Scholar
  92. Zhang T, Stackhouse PW, Chandler WS, Westberg DJ (2014) Application of a global-to-beam irradiance model to the NASA GEWEX SRB dataset: an extension of the NASA surface meteorology and solar energy datasets. Sol Energy 110:117–131CrossRefGoogle Scholar
  93. Zhang Y (2016) Simplified analytical model for investigating the output power of solar array on stratospheric airship. Int’l J Aeronautical Space Sci 17:432–441CrossRefGoogle Scholar
  94. Zhong X, Kleissl J (2015) Clear sky irradiances using REST2 and MODIS. Sol Energy 116:144–164CrossRefGoogle Scholar
  95. Zhu W, Xu Y, Li J, Du H, Zhang L (2018) Research on optimal solar array layout for near-space airship with thermal effect. Sol Energy 170:1–13CrossRefGoogle Scholar
  96. Ziemke JR, Chandra S, Labow GJ, Bhartia PK, Froidevaux L, Witte JC (2011) A global climatology of tropospheric and stratospheric ozone derived from Aura OMI and MLS measurements. Atmos Chem Phys 11:9237–9251CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Solar Consulting ServicesColebrookUSA

Personalised recommendations