Validation of an empirical model for photosynthetically active radiation

Alados, I.; Alados-Arboledas, Lucas

doi:10.1002/(sici)1097-0088(199908)19:10<1145::aid-joc428>3.0.co;2-3

Cited by 23 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, when forcing the estimation models through the origin, the result could remove some long-term trends in climate change. Moreover, previous models have only considered the main effects of the climatic and geometric variables, while their interactions have never been taken into consideration or incorporated into predictive models (Alados and Alados-Arboledas 1999;Tsubo and Walker 2005). We believe that these interaction terms should be included to improve model predictions.…”

Section: Predicting Par Valuesmentioning

confidence: 99%

“…PAR is important as it is the sole energy source used by plants for photosynthesis reactions that partially convert physical solar energy into bioenergy-carrying biomass (Mariscal et al 2000;Tsubo and Walker 2005;Myers 2005). Precise estimation of incident PAR is therefore essential in assessing and modeling plant growth and biological production management in different vegetative ecosystems (Alados and Alados-Arboledas 1999). Such estimation could be integrated with plant growth models and decision-making systems to optimize vegetation management activities and solar energy conversion efficiency into bioenergy-loading biomass (Spitters et al 1986;Papaionnou et al 1993;Alados et al 1996;Gueymard 2000).…”

Section: Introductionmentioning

confidence: 99%

“…Even though PAR is extremely important, it is often not measured in most meteorological stations around the world; therefore, it has to be estimated from the commonly measured global solar radiation (R S ). As a result, PAR is usually estimated with other measured variables as follows, using one of three approaches: (a) the fractional energy of PAR to global solar radiation (fE; Kvifte et al 1983;Papaionnou et al 1993;Udo and Aro 1999;Mõttus et al 2001;Tsubo and Walker 2005), (b) the fraction of photon flux/energy conversion of PAR (fFEC; Alados et al 1996;Aro 1999, 2000;Alados et al 1996;Alados and Alados-Arboledas 1999;Al-Shooshan 1997;Finch et al 2004;Jacovides, et al 2004Jacovides, et al , 2007, or (c) the PAR photon flux density (PPFD;McCree 1966;Papaionnou et al 1993;Alados et al 1996;Jacovides et al 2004). Such processes were driven by different quantitative methods (McCree 1972;McCartney 1978;Udo and Aro 1999), and each method has its positive and negative attributes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dynamics of photosynthetic photon flux density (PPFD) and estimates in coastal northern California

Smith

Jacovides

et al. 2010

Theor Appl Climatol

View full text Add to dashboard Cite

Section: Predicting Par Valuesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamics of photosynthetic photon flux density (PPFD) and estimates in coastal northern California

Smith

Jacovides

et al. 2010

Theor Appl Climatol

View full text Add to dashboard Cite

“…et al[5] developed the following HB model for University of Almeria site as: -Arboledas[117] calibrated the following HB model for University of Almeria site as: et al[72] fitted the following HB models for contiguous United States as:…”

mentioning

confidence: 99%

A Global Review of Empirical Models for Estimating Photosynthetically Active Radiation

Nwokolo

Amadi

2018

Tr Ren Energy

View full text Add to dashboard Cite

A good working knowledge of photosynthetically active radiation (PAR) is of vital requirement for determining the terrestrial photosynthesis, primary productivity calculation, ecosystem-atmosphere carbon dioxide, plant physiology, biomass production, natural illumination in greenhouses, radiation climate, remote sensing of vegetation, and radiation regimes of plant canopy, photosynthesis, productivity models of vegetation, etc. However, routine measurement of PAR is not available in most location of interest across the globe. During the past 77 years in order to estimate PAR on hourly, daily and monthly mean basis, several empirical models have been developed for numerous locations globally. As a result, numerous input parameters have been utilized and different functional forms applied. This study was aim at classifying and reviewing the empirical models employed for estimating PAR across the globe. The empirical models so far utilized were classified into ten main categories and presented base on the input parameters applied. The models were further reclassified into numerous main sub-classes (groups) and finally presented according to their developing year. In general, 757 empirical models, 62 functional forms and 32 groups were reported in literature for estimating PAR across the globe. The empirical models utilized were equally compared with models developed using different artificial neural network (ANN); and the result revealed that ANN models are more suitable for estimating PAR across the globe. Thus, this review would provide solar energy researchers with input parameters and functional forms that have been widely used to up to date, and recognizing their importance in estimating PAR globally.

show abstract

“…Different approaches have been used to derive PAR: measurements with dedicated sensors (e.g. Alados and Alados-Arboledas, 1999), estimates from satellite observations (e.g. Frouin and Pinker, 1995), as a fraction of the broadband solar irradiance (e.g.…”

Section: Introductionmentioning

confidence: 99%

A long-term time series of global and diffuse photosynthetically active radiation in the Mediterranean: interannual variability and cloud effects

Trisolino¹,

Sarra²,

Anello³

et al. 2018

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Measurements of global and diffuse photosynthetically active radiation (PAR) have been carried out on the island of Lampedusa, in the central Mediterranean Sea, since 2002. PAR is derived from observations made with multi-filter rotating shadowband radiometers (MFRSRs) by comparison with a freshly calibrated PAR sensor and by relying on the on-site Langley plots. In this way, a long-term calibrated record covering the period 2002–2016 is obtained and is presented in this work. The monthly mean global PAR peaks in June, with about 160 W m−2, while the diffuse PAR reaches 60 W m−2 in spring or summer. The global PAR displays a clear annual cycle with a semi amplitude of about 52 W m−2. The diffuse PAR annual cycle has a semi amplitude of about 12 W m−2. A simple method to retrieve the cloud-free PAR global and diffuse irradiances in days characterized by partly cloudy conditions has been implemented and applied to the dataset. This method allows retrieval of the cloud-free evolution of PAR and calculation of the cloud radiative effect, CRE, for downwelling PAR. The cloud-free monthly mean global PAR reaches 175 W m−2 in summer, while the diffuse PAR peaks at about 40 W m−2. The cloud radiative effect, CRE, on global and diffuse PAR is calculated as the difference between all-sky and cloud-free measurements. The annual average CRE is about −14.7 W m−2 for the global PAR and +8.1 W m−2 for the diffuse PAR. The smallest CRE is observed in July, due to the high cloud-free condition frequency. Maxima (negative for the global, and positive for the diffuse component) occur in March–April and in October, due to the combination of elevated PAR irradiances and high occurrence of cloudy conditions. Summer clouds appear to be characterized by a low frequency of occurrence, low altitude, and low optical thickness, possibly linked to the peculiar marine boundary layer structure. These properties also contribute to produce small radiative effects on PAR in summer. The cloud radiative effect has been deseasonalized to remove the influence of annual irradiance variations. The monthly mean normalized CRE for global PAR can be well represented by a multi-linear regression with respect to monthly cloud fraction, cloud top pressure, and cloud optical thickness, as determined from satellite MODIS observations. The behaviour of the normalized CRE for diffuse PAR can not be satisfactorily described by a simple multi-linear model with respect to the cloud properties, due to its non-linear dependency, in particular on the cloud optical depth. The analysis suggests that about 77 % of the global PAR interannual variability may be ascribed to cloud variability in winter.

show abstract

Validation of an empirical model for photosynthetically active radiation

Cited by 23 publications

References 17 publications

Dynamics of photosynthetic photon flux density (PPFD) and estimates in coastal northern California

Dynamics of photosynthetic photon flux density (PPFD) and estimates in coastal northern California

A Global Review of Empirical Models for Estimating Photosynthetically Active Radiation

A long-term time series of global and diffuse photosynthetically active radiation in the Mediterranean: interannual variability and cloud effects

Contact Info

Product

Resources

About