Photosynthesis Under Field Conditions. VI. Solar Radiation Balance and Photosynthetic Efficiency 1

1964 ◽  
Vol 56 (3) ◽  
pp. 249-253 ◽  
Author(s):  
C. S. Yocum ◽  
L. H. Allen ◽  
E. R. Lemon
Keyword(s):  
Solar Radiation ◽  
Photosynthetic Efficiency ◽  
Field Conditions ◽  
Radiation Balance

scholarly journals Radiation balance of coffee hedgerows

2008 ◽  
Vol 12 (3) ◽  
pp. 274-281 ◽  
Author(s):  
Luiz R. Angelocci ◽  
Fábio R. Marin ◽  
Felipe G. Pilau ◽  
Evandro Z. Righi ◽  
José L. Favarin
Keyword(s):  
Solar Radiation ◽  
Cover Crops ◽  
Ground Cover ◽  
Global Solar Radiation ◽  
Important Variable ◽  
Field Conditions ◽  
Radiation Balance ◽  
Net Radiation ◽  
Energy Exchanges ◽  
Good Agreement

The radiation balance of hedgerows is an important variable in studies of mass and energy exchanges between parcial ground cover crops and the atmosphere. This paper describes a device with eight net radiometers encompassing the plants of a hedgerow. The radiometers were moved along a length of hedgerow, in a continuous and reversible movement. The canopy net radiation in this length (Rnc) was found by integration of the measurements over the notional cylinder formed. The device showed good performance and provided reliable measurements of Rnc of coffee hedgerows, showing itselfto be an useful technique of measurement in field conditions. Good correlations between Rnc and global solar radiation, turfgrass and coffee crop net radiation were found in 15-min, daytime and 24-hr periods, allowing the possibility of estimating Rnc from these simple measurements. Beer’s law was also used to have an independent estimation of Rnc. A good agreement was found between values of Rnc estimated by this law of attenuation and those integrated by the device in periods of 15 min, with overestimation of 10%, whereas for values integrated over daytime periods the agreement was not satisfactory.

scholarly journals The influence of observed and modelled net longwave radiation on the rate of estimated potential evapotranspiration

2019 ◽  
Vol 67 (3) ◽  
pp. 280-288 ◽  
Author(s):  
Jitka Kofroňová ◽  
Miroslav Tesař ◽  
Václav Šípek
Keyword(s):  
Czech Republic ◽  
Solar Radiation ◽  
Potential Evapotranspiration ◽  
Sunshine Duration ◽  
Longwave Radiation ◽  
Radiation Balance ◽  
Parameter Calibration ◽  
Atmospheric Emissivity ◽  
The Bohemian Forest ◽  
The Difference

Abstract Longwave radiation, as part of the radiation balance, is one of the factors needed to estimate potential evapotranspiration (PET). Since the longwave radiation balance is rarely measured, many computational methods have been designed. In this study, we report on the difference between the observed longwave radiation balance and modelling results obtained using the two main procedures outlined in FAO24 (relying on the measured sunshine duration) and FAO56 (based on the measured solar radiation) manuals. The performance of these equations was evaluated in the April–October period over eight years at the Liz experimental catchment and grass surface in the Bohemian Forest (Czech Republic). The coefficients of both methods, which describe the influence of cloudiness factor and atmospheric emissivity of the air, were calibrated. The Penman-Monteith method was used to calculate the PET. The use of default coefficient values gave errors of 40–100 mm (FAO56) and 0–20 mm (FAO24) for the seasonal PET estimates (the PET was usually overestimated). Parameter calibration decreased the FAO56 error to less than 20 mm per season (FAO24 remained unaffected by the calibration). The FAO56 approach with calibrated coefficients proved to be more suitable for estimation of the longwave radiation balance.

scholarly journals STRUCTURE AND INTERANNUAL DYNAMICS OF THE REGIONAL ECOSYSTEMS RADIATION BALANCE OF THE PLAIN CRIMEA

Ekosistemy ◽  
2021 ◽  
pp. 5-15
Author(s):  
R. V. Gorbunov ◽  
T. Yu. Gorbunova ◽  
V. A. Tabunshchik ◽  
A. V., Drygval
Keyword(s):  
Solar Radiation ◽  
Short Wave ◽  
Radiation Balance ◽  
Total Solar Radiation ◽  
Western Coast ◽  
Climate Data ◽  
Crimean Peninsula ◽  
Wave Part ◽  
Interannual Dynamics ◽  
Landscape Level

The research team calculated the values of the radiation balance elements of the plain Crimea ecosystems on the bases of open databases of climate data and GIS-modeling and, moreover, analyzed their spatial and temporal differentiation. It is revealed that the spatial distribution of the radiation balance is characterized by an increase in values from the center to the coast of the peninsular. It correlates with the spatial differentiation of both total solar radiation and all other elements of the short-wave part of the radiation balance. There is a significant excess of radiation balance values of the plateau landscape level ecosystems over values of the hydromorphic landscape level ecosystems. This difference is determined by the location of selected key areas on the western coast of the Crimean Peninsula, which is characterized by the maximum values of total solar radiation supply. The elements of the long-wave part of the radiation balance change in the opposite direction, compared with the short-wave part of the radiation balance, which is associated with an increase of air temperature and climate continentality in the direction from the coast to the center of the peninsula. Two periods were identified in the interannual dynamics corresponding to the change of the circulatory periods of the Northern Hemisphere. In general, the considered ecosystems are characterized by trends of increasing radiation balance values in conditions of growth of all its elements. Such growth is provided by significant increase of values during the second period compared with the negative trends of radiation balance values for a number of ecosystems in the first one.

scholarly journals Solar radiation use efficiency by soybean under field conditions in the Amazon region

2009 ◽  
Vol 44 (10) ◽  
pp. 1211-1218 ◽  
Author(s):  
Paulo Jorge de Oliveira Ponte de Souza ◽  
Aristides Ribeiro ◽  
Edson José Paulino da Rocha ◽  
José Renato Bouça Farias ◽  
Renata Silva Loureiro ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Leaf Area ◽  
Biomass Production ◽  
Amazon Region ◽  
Field Conditions ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Natural Field ◽  
Use Efficiency ◽  
Radiation Use

The objective of this work was to evaluate the efficiency of soybean (Glycine max) in intercepting and using solar radiation under natural field conditions, in the Amazon region, Brazil. The meteorological data and the values of soybean growth and leaf area were obtained from an agrometeorological experiment carried out in Paragominas, Pará state, during 2007 and 2008. The radiation use efficiency (RUE) was obtained from the ratio between the above-ground biomass production and the intercepted photosynthetically active radiation (PAR) accumulated to 99 and 95 days after sowing, in 2007 and 2008, respectively. Climatic conditions during the experiment were very distinct, with reduction in rainfall in 2007, which began during the soybean mid-cycle, due to the El Niño phenomenon. An important reduction in the leaf area index and biomass production was observed during 2007. Under natural field conditions in the Amazon region, the values of RUE were 1.46 and 1.99 g MJ-1 PAR in the 2007 and 2008 experiments, respectively. The probable reason for the differences found between these years might be associated to the water restriction in 2007 coupled with the higher air temperature and vapor pressure deficit, and also to the increase in the fraction of diffuse radiation that reached the land surface in 2008.

Shipboard Measurements of Aerosol Properties in the Coupled Ocean-Atmosphere System of the Northwest Tropical Atlantic

2020 ◽  
Author(s):  
Tim Bates ◽  
Patricia Quinn
Keyword(s):  
Solar Radiation ◽  
Marine Boundary Layer ◽  
Cloud Condensation Nuclei ◽  
Cloud Droplet ◽  
Lower Atmosphere ◽  
Radiation Balance ◽  
Tropical Atlantic ◽  
Shallow Convection ◽  
Condensation Nuclei ◽  
Aerosol Properties

<p>The fair-weather cumulus clouds, that cover much of the low-latitude oceans, affect the radiation balance of the planet by reflecting incoming solar radiation and absorbing outgoing longwave radiation.  These clouds also drive atmospheric circulation by mixing the lower atmosphere in a process called shallow convection.  This mixing, in turn, affects sea surface temperature and salinity by moderating the air-sea exchange of energy and moisture.  Marine boundary layer (MBL) atmospheric aerosols play a role in the processes described above by scattering and absorbing solar radiation and by serving as cloud condensation nuclei (CCN) thereby influencing cloud droplet concentrations and size; the extent, lifetime, and albedo of clouds; and the frequency and intensity of precipitation. Quantifying the role of aerosols over the Northwest Tropical Atlantic is critical to advance understanding of shallow convection and air-sea interactions.</p><p>MBL aerosol properties were measured aboard the RV Ronald H. Brown during the EUREC4A and ATOMIC field studies in January/February 2020.  Aerosols encountered during the study include background sulfate/sea spray particles and African dust/biomass burning particles.  Aerosol physical, chemical, optical and cloud condensation nuclei properties will be presented and their interaction with local and regional circulation.</p>

scholarly journals Analysis of the Solar Collectors Installation on a Roof of the Small Public Building in Poland, Lithuania and Spain—A Case Study

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1272 ◽  
Author(s):  
Dorota Anna Krawczyk ◽  
Mirosław Żukowski ◽  
Antonio Rodero ◽  
Ruta Bilinskiene
Keyword(s):  
Solar Radiation ◽  
Tilt Angle ◽  
Solar Collector ◽  
Simulation Software ◽  
Hot Water ◽  
Government Support ◽  
Office Building ◽  
Radiation Balance ◽  
Solar Collectors

A solar collector market is most European countries is at the stage of continuous development, however its expansion rate differs. It shows that much more factors than only the local solar radiation is important, including a technology progress, costs, local manufactures’ engagement, an economic government support or an environmentally consciousness raising relevant to a mitigating climate change. We conducted the analysis for a public office building, with a few toilets and a social room, used by 54 people. As a primary heat source for HVAC and DHW systems an oil boiler was used, whereas solar collectors were considered as an energy source for hot water preparation. The analysis was conducted for three locations of the building: Bialystok (Poland), Cordoba (Spain) and Kaunas (Lithuania), using a simulation software delivered within the framework of VIPSKILLS project. Theoretical hot water consumption was considered as 3–7 dm3/(day person) in compliance with national recommendations. It was found that beam solar radiation share in a total radiation balance was nearly twice higher in Cordoba than in Bialystok or Kaunas. The highest efficiency (44%) was estimated in Cordoba for solar collectors installed with the tilt angle between 45–50°. In case of Bialystok and Kaunas the efficiency was lower than in Cordoba and nearly equal 40–41% and the recommended tilt angle was in a range 30– 45°.

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