New empirical relationships for determining global PAR from measurements of global solar radiation, infrared radiation or sunshine duration

Udo, Sunday O.; Aro, T O

doi:10.1002/1097-0088(200008)20:10<1265::aid-joc530>3.0.co;2-c

Cited by 19 publications

(15 citation statements)

References 46 publications

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“…Values for intercepted PAR each day are summed for each plot. The slope of the linear Measurements of photosynthetically active radiation (PAR) intercepted by plants should be made between 10 a.m. and 2 p.m. in clear-sky conditions only, because cloud cover can affect the magnitude of PAR [21]. The location or site name, date and sky conditions are all recorded.…”

Section: Derivation Of Rue Valuesmentioning

confidence: 99%

A Review of Modeled Water Use Efficiency of Highly Productive Perennial Grasses Useful for Bioenergy

Kiniry

Kim²

2020

Agronomy

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Whole plant productivity is obviously the ultimate product of leaf photosynthesis and this has led to numerous efforts to relate the two. However, often with perennial grasses, plant productivity is more sink-limited than source-limited, causing the linkage between the photosynthetic rate and productivity to be weak or nonexistent. This has led to a different approach, characterizing plant productivity in terms of the efficiency of intercepted light use in producing biomass, also called radiation use efficiency. Likewise, the efficiency of the use of water to produce plant biomass, or water use efficiency, has been the object of much interest. The use of a simulation model to quantify biomass, using radiation use efficiency in parallel with a daily water balance simulation, allows for the effective calculation of water use efficiency. In this project, the process of determining radiation use efficiency with field data is described, as well as example values for highly productive perennial grasses useful for feedstock for bioenergy. In addition, values of water use efficiency for these grasses are reported and compared with other perennial grasses and common cultivated crops.Water requirements for growing switchgrass and giant miscanthus are often an issue. Without adequate water, their biomass yields can be reduced by 45%-80% of total biomass yields [10,11]. Moreover, competition for water with other users makes maximizing water use efficiency vitally important. Again, process-based simulation models are valuable tools since they simulate the dynamics of crop water use based on evaporation of soil water, leaf transpiration, weather, and dynamics of plant communities. Quantifying Photosynthetic Performance via Two Approaches: Single Leaf Photosynthesis vs. Radiation Use Efficiency (RUE)There are many plant simulation models based on single leaf photosynthesis, which is then scaled up to the whole leaf canopy. Such models, such as ORYZA for rice (Oryza sativa L.) [12,13], are based on the assumption that photosynthesis is a major driver and determinant for whole plant productivity. However, frequently grass systems have been shown to be more sink-limited than source-limited. They often rely more on the processes of tiller production, leaf development, and leaf canopy orientation.Examples:

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Section: Derivation Of Rue Valuesmentioning

confidence: 99%

A Review of Modeled Water Use Efficiency of Highly Productive Perennial Grasses Useful for Bioenergy

Kiniry

Kim²

2020

Agronomy

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“…The clear-sky parameterization explicitly considers the radiative extinction processes due to air molecules, aerosols, ozone, and water vapor. Many investigations are concerned with such parameterization scheme [Gueymard, 1989;Alados-Arboledas et al, 2000;Alados et al, 2002], but few studies focused on the effect of cloud on PAR [Udo and Aro, 2000;Qin et al, 2012]. presented a semiphysical model to estimate PAR under cloudy conditions based on the cloud transmittance functions for three different types of clouds.…”

Section: Introductionmentioning

confidence: 99%

Reconstruction of daily photosynthetically active radiation and its trends over China

et al. 2013

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[1] Photosynthetically active radiation (PAR) is widely required in ecological studies, but it is not routinely measured at China Meteorological Administration (CMA) stations. In this study, a PAR model is utilized to estimate daily PAR from routine meteorological parameters (air temperature, air pressure, relative humidity, and sunshine duration) at CMA stations. The estimate is evaluated against measurements at 10 Chinese Ecosystem Research Network (CERN) stations. The model can produce PAR with mean bias errors of À2.4 W m À2, root mean square errors of 14.0 W m À2, and correlation coefficient (R) of 0.92 at all CERN stations. Comparison with a locally calibrated model indicates that the estimate has a comparable or even higher accuracy than the local model calibrated with CERN data. Another evaluation at an independent site further indicates that our estimate has higher accuracy than the local model at stations independent of CERN. Finally, a 50 year data set of daily PAR at 716 CMA stations over China is reconstructed by the validated model, and its climatology and long-term variations over China are analyzed. The data set would substantially contribute to ecological studies in China.

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“…The concentration of CDOM was described by the mean a CDOM between 300 and 700 nm, which was an arithmetic mean of absorption coefficients between 300 nm and 700 nm. Solar radiation was measured at 1-s intervals with a LI-190SZ quantum sensor (LiCor, Inc) and converted to global radiation assuming that irradiance at 400-700 nm was 50 % of global radiation (Udo and Aro, 2000).…”

Section: Sunlight Effects On Adsorbed Docmentioning

confidence: 99%

Effects of clay mineral turbidity on dissolved organic carbon and bacterial production

2005

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Effects of inorganic turbidity from clay minerals on allochthonous dissolved organic matter (DOM), its consumption by bacteria and photodegradation by solar radiation were investigated. In controlled experiments of adsorption of DOM of six specific leaf leachates onto montmorillonite, kaolinite, and clay extracted from drainage basin soil, up to 31 mg C of leaf leachate was adsorbed g clay -1 . A suspension of clay adsorbed preferentially the chromophoric portion of dissolved organic carbon (DOC) and enhanced photochemical decomposition of CDOM and DOC under experimental conditions representative of the surface of the water column. Significant amounts of DOM were desorbed from the clay-organic aggregates Aquat. Sci. 67 (2005) 51-60 Aquatic Sciences into water of low ionic strength and low concentrations of DOM. Solar radiation decomposed chromophoric organic matter adsorbed onto suspended clay in part to low molecular organic products and to CO 2 . Montmorillonite clay significantly decreased (>90%) bacterial production, unless the clay had appreciable adsorbed DOM. With organic matter adsorbed, the addition of montmorillonite or of natural clay minerals resulted in significant increases (+100%) in bacterial production. This increase indicated that clay-organic matter aggregates can play an important role in the transport of terrestrial organic matter to aquatic environments and that this organic matter adsorbed to clay particles is available to bacteria through desorption.

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New empirical relationships for determining global PAR from measurements of global solar radiation, infrared radiation or sunshine duration

Cited by 19 publications

References 46 publications

A Review of Modeled Water Use Efficiency of Highly Productive Perennial Grasses Useful for Bioenergy

A Review of Modeled Water Use Efficiency of Highly Productive Perennial Grasses Useful for Bioenergy

Reconstruction of daily photosynthetically active radiation and its trends over China

Effects of clay mineral turbidity on dissolved organic carbon and bacterial production

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