Extraterrestrial Solar Radiation Research Articles

The Simulation of Extraterrestrial Solar Radiation Based on SOTER in Zhangpu Sample Plot and Fujian Province

The study establishes DEMs and the computer models of daily extraterrestrial radiation in Zhangpu sample plot and Fujian province and annually extraterrestrial radiation in Fujian province using GIS base on SOTER. The results indicate that the daily extraterrestrial radiation is mainly 17-18MJ/m 2 in Zhangpu, the one is mainly 14-18MJ/m 2 and the annually extraterrestrial radiation is mainly 5000~7000MJ/m 2 in Fujian province. The influence of topographic feature is significant, in general the solar radiation in the chine is bigger than the one in the valley, and the one in the sunny slope is bigger than in the shady slope, the high radiation value appears primarily in the sunny slope with the chine as demarcation line. The method can extract daily and annually extraterrestrial radiation with high precision and speediness at small and moderate scales which don’t take cloud into consideration. The orientation of future research is to improve precision by RS images and combine with SOTER.

Ionising radiation exposure of the population of the United States: NCRP Report No. 160

This report is a long-awaited sequel to NCRP Report No. 93 (published in 1987) and provides a comprehensive re-evaluation of the exposure of the US population to all natural and man-made sources of ionising radiation in 2006—some 25 y after the previous assessment for the early 1980s. Over this period, the average annual effective dose per individual in the US population (EUS) from all sources has increased by a factor of 1.7 to 6.2 mSv, with the increase being almost entirely due to the dramatic growth of relatively high-dose medical imaging procedures using X-rays and radionuclides. The report first considers exposures from ubiquitous background radiation, which contribute 50% of the EUS from all sources (3.1 mSv). They are divided into extra-terrestrial cosmic and solar radiation, terrestrial radiation from surface soil and rocks, internal exposures from inhaled radon and thoron seeping out of the ground and internal...

Analysis of terrestrial solar radiation exergy

Based on Candau’s definition of radiative exergy, the exergy of the extraterrestrial and the terrestrial solar radiation are computed and compared by using the solar spectral radiation databank developed by Gueymard. The results show that within the spectrum region from 0.28 to 4.0 μm, the total energy quality factor (i.e., the exergy-to-energy ratio) of extraterrestrial solar radiation is about 0.9292, and that of the global terrestrial solar radiation is about 0.9171 under US standard atmosphere condition and zero solar zenith angle. The terrestrial solar spectral radiation exergy flux is large in the near ultraviolet and the visible light region. The reference radiation exergy spectra are obtained under atmospheric conditions consistent with ASTM standard G173-03. The effect of tilt angle on the terrestrial solar radiative exergy for inclined surface, and the effect of air mass on total energy quality factor of the terrestrial solar radiation for horizontal surface are analyzed. With the increase of tilt angle, the terrestrial solar spectral radiation exergy flux initially increases and then decreases, the total energy quality factor of the diffuse part decreases monotonically, while that of the direct part is invariant. The total energy quality factor of the direct, the diffuse and the global terrestrial solar radiation all decrease with the increase of air mass.

How much exergy one can obtain from incident solar radiation?

A thermodynamic model is proposed to study the exergetic content of incident solar radiation reaching on the Earth’s surface which can be used to produce work through a dually cascaded thermodynamic cycle. The “topping” cycle is an ad hoc engine created by nature that connects the outer shell of the terrestrial atmosphere (which is in equilibrium with the extraterrestrial solar radiation) to the collector of a solar heat engine operating on the Earth’s surface. The work produced by the topping cycle is dissipated in form of scattering, absorption, heat, movement of air masses (wind), etc. The “bottoming” cycle is a heat engine operating between the collector and surrounding temperatures, and delivers useful work. It is shown that the maximum work extractable from this system as exergy is obtained when both cycles operate reversibly. An expression for this maximum work, which represents the exergy of incident solar radiation on the Earth’s surface, is proposed. The application of the present model is illustrated and validated by calculating the exergy of solar radiation based on some measurements. The results obtained by the present model are compared to the ones obtained through other models available in the open literature.

Distributed Modeling of Diffuse Solar Radiation over Rugged Terrain of the Yellow River Basin

AbstractIn view of the compositive action of astronomy, atmosphere, macro‐geographical and local topography factors on diffuse solar radiation (DSR), influences of sky factors and ground factors are separated. Using the extraterrestrial solar radiation model and the terrain openness model, found on DEM data, influences of ground factors on DSR are considered. Using the horizontal diffuse solar radiation model, simulated by routine meteorological observation data, influences of sky factors on DSR are considered. Based on anisotropy scattering mechanism, with DEM data and routine meteorological observations as input, a distributed model for calculating DSR over rugged terrains is developed, which furnishes a new line of thoughts to DSR simulation over rugged terrain. Using DEM data with resolution of 1km × 1km as the general characterization of terrain, distributed modeling of DSR quantity over the Yellow River Basin is successfully achieved.

Estimation of solar radiation and its application to crop simulation models in Greece

Lack of data on site-specific daily solar radiation (Rg) is a significant impediment for most crop modeling applications. For this reason, 5 methods for estimating Rg were tested: the Angstrom-Prescott equation (AP), the Supit - van Kappel formula (SK) and 3 temperature-based methods: Campbell-Donatelli model, Hargreaves equation, and piecewise multiple linear regres- sions with a breakpoint (PLR). To overcome the lack of long and continuous time series of Rg mea- surements at multiple sites, satellite-derived Rg from the HelioClim-1 database were tested against observations from 2 stations, and then interpolated for 12 additional stations. When sunshine duration data were available, the AP equation was best, because it (1) produced intercepts and slopes closest to zero and unity, respectively and (2) had the lowest relative RMSE (9 to 18.6%). When cloud cover observations and data on maximum and minimum temperatures were available, the SK equation was equally effective as AP in most assessment metrics. When the only data for a site were daily maxi- mum and minimum temperatures, the PLR approach with a breakpoint, which reflects the value at which the response of daily Rg changes as a function of the extraterrestrial solar radiation RA and the diurnal temperature range, performed best. The mean relative RMSE of the PLR approach was <3.7% higher than that of AP. The SK equation provided the most suitable simulation of measured Rg for the CERES-Wheat crop model, while among the temperature-based methods PLR produced the smallest yield errors. Future validation efforts should explore the validity of the PLR model in other regions and under regimes with greater availability of Rg data

Equations for estimating global solar radiation in data sparse regions

The knowledge of the amount of solar radiation in an area/region is very essential in the field of Solar Energy Physics. In this work two equations are put forward for estimating global solar radiation from common climate variables in data sparse regions. The first is the Hargreaves equation, R s=0.16 R a T d 0.5 where R a is the extraterrestrial solar radiation and T d is the temperature difference (maximum minus minimum), while the second is the Angstrom equation, R s= R a(0.28+0.39n/N) where n and N are the measured sunshine hours and the maximum daylight duration respectively. The global solar radiation estimated by the two equations for three sites, Owerri (5°28′N, 7°2′E), Umudike (5°29′N, 7°33′E) and Ilorin (8°32′N, 4°46′E), located in different climate zones of in Nigeria, West Africa, are in agreement with those of earlier workers and that from Photovoltaic Geographic Information System (PVGIS) project. The implication of this in solar photovoltaic applications has been stressed.

Study of erythemal, UV (A + B) and global solar radiation in Valencia (Spain)

AbstractAlthough ultraviolet B radiation (UVB), the solar radiation band between 280 and 315 nm, is only a small fraction of the extraterrestrial solar radiation, it accounts for 80% of the harmful effects of exposure to the sun. In this work values of erythemal solar irradiance (UVER) measured in Valencia on a horizontal plane in the period between June 2003 and June 2005 are analysed and compared with measures of UV (A + B) and global irradiances on a horizontal plane. UV erythemal (UVER) irradiance has been measured using a YES‐UVB‐1 broadband radiometer; UV (A + B) irradiance has been measured using a TUVR Eppley radiometer with spectral response between 290 and 385 nm and global irradiance on a horizontal plane has been measured with a Kipp and Zonen model CM‐6 broadband radiometer. A study of a statistically representative index of UVER irradiance has been made by comparing with the results corresponding to UV (A + B) irradiance and those of global irradiance on a horizontal plane. A fit has been performed using all the irradiance values to estimate the UVER and UV (A + B) components as functions of the other ranges. We have calculated for each month the irradiation acumulated during an average day, for the UVER, UV (A + B) and global, the highest values was 4.1, 791 and 25 146 kJ/m2 respectively. Copyright © 2007 Royal Meteorological Society

Lichens Survive in Space: Results from the 2005 LICHENS Experiment

This experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. In particular, the damaging effect of various wavelengths of extraterrestrial solar UV radiation was studied. The lichens used were the bipolar species Rhizocarpon geographicum and Xanthoria elegans, which were collected above 2000 m in the mountains of central Spain and as endolithic communities inhabiting granites in the Antarctic Dry Valleys. Lichens were exposed to space in the BIOPAN-5 facility of the European Space Agency; BIOPAN-5 is located on the outer shell of the Earth-orbiting FOTON-M2 Russian satellite. The lichen samples were launched from Baikonur by a Soyuz rocket on May 31, 2005, and were returned to Earth after 16 days in space, at which time they were tested for survival. Chlorophyll fluorescence was used for the measurement of photosynthetic parameters. Scanning electron microscopy in back-scattered mode, low temperature scanning electron microscopy, and transmission electron microscopy were used to study the organization and composition of both symbionts. Confocal laser scanning microscopy, in combination with the use of specific fluorescent probes, allowed for the assessment of the physiological state of the cells. All exposed lichens, regardless of the optical filters used, showed nearly the same photosynthetic activity after the flight as measured before the flight. Likewise, the multimicroscopy approach revealed no detectable ultrastructural changes in most of the algal and fungal cells of the lichen thalli, though a greater proportion of cells in the flight samples had compromised membranes, as revealed by the LIVE/DEAD BacLight Bacterial Viability Kit. These findings indicate that most lichenized fungal and algal cells can survive in space after full exposure to massive UV and cosmic radiation, conditions proven to be lethal to bacteria and other microorganisms. The lichen upper cortex seems to provide adequate protection against solar radiation. Moreover, after extreme dehydration induced by high vacuum, the lichens proved to be able to recover, in full, their metabolic activity within 24 hours.

A Simple Solar Radiation Index for Wildlife Habitat Studies

Abstract: Solar radiation is a potentially important covariate in many wildlife habitat studies, but it is typically addressed only indirectly, using problematic surrogates like aspect or hillshade. We devised a simple solar radiation index (SRI) that combines readily available information about aspect, slope, and latitude. Our SRI is proportional to the amount of extraterrestrial solar radiation theoretically striking an arbitrarily oriented surface during the hour surrounding solar noon on the equinox. Because it derives from first geometric principles and is linearly distributed, SRI offers clear advantages over aspect‐based surrogates. The SRI also is superior to hillshade, which we found to be sometimes imprecise and ill‐behaved. To illustrate application of our SRI, we assessed niche separation among 3 ungulate species along a single environmental axis, solar radiation, on the northern Yellowstone winter range. We detected no difference between the niches occupied by bighorn sheep (Ovis canadensis) and elk (Cervus elaphus; P = 0.104), but found that mule deer (Odocoileus hemionus) tended to use areas receiving more solar radiation than either of the other species (P &lt; 0.001). Overall, our SRI provides a useful metric that can reduce noise, improve interpretability, and increase parsimony in wildlife habitat models containing a solar radiation component.

Mutagenesis by outer space parameters other than cosmic rays

We have studied the ability of microorganisms to cope with the complex interplay of the parameters of space in experiments in low Earth orbit and using space simulation facilities on ground. Emphasis was laid on space parameters other than cosmic rays. The studies are directed towards understanding prebiotic chemical evolution and biological evolution processes, and interplanetary transfer of life. Effects of space vacuum: Space experiments have shown that up to 70% of bacterial and fungal spores survived short-term exposure to space vacuum. The chances of survival in space were increased when spores were embedded in chemical protectants such as sugars, or salt crystals, or when they were exposed in multilayer. During the six years lasting LDEF mission up to 80% of bacterial spores survived exposure to space vacuum. A 10-fold increased mutation rate over the spontaneous rate has been observed in spores of Bacillus subtilis after exposure to space vacuum, which is probably based on a unique molecular signature of tandem-double base change at restricted sites in the DNA. In addition, DNA strand breaks have been observed to be induced by vacuum treatment. Effects of extraterrestrial solar UV radiation: Solar UV radiation has been found to be the most deleterious factor of space. The reason for this is the highly energetic UV-C and vacuum UV radiation that is directly absorbed by the DNA and which induces specific photoproducts in the DNA that are highly mutagenic and lethal. The damaging effect of extraterrestrial solar UV radiation was even aggravated, when the spores were simultaneously exposed to both, solar UV radiation and space vacuum. In order to investigate the mutagenic potential of solar UV radiation, DNA of the Escherichia coli plasmid pUC19 was exposed to selected wavebands of UV radiation (from vacuum UV to UV-A) by use of a solar simulator and space simulation facilities. Action spectra revealed that for vacuum UV different kinds of photochemical damage contribute to inactivation and mutation induction. Sequencing of the UV-induced l acZ′ mutants provided mutation spectra and mutational hot spots for the various UV regions. In all UV regions, the predominant base substitution was the G:C to A:T transition. A:T to T:A transversions were increasingly produced by short-waveband UV, whereas G:C to C:G transversions predominated after exposure to UV-A. Deletions of more than one base pair were only detected after exposure to vacuum UV radiation.

Potential impacts of climate change on water availability for crops in the Okanagan Basin, British Columbia

Crop water demand in the Okanagan Basin was determined for 1961 to 1990, 2010 to 2039, 2040 to 2069, and 2070 to 2099. Daily station temperature data were spatially interpolated to a 1 × 1 km grid and adjusted for elevation. Daily precipitation data were estimated across four climatic regions. Output from three global climate models (GCM), CGCM2, CSIROMk2 and HadCM3 was used to create future daily climate. Daily potential evapo-transpiration (grass reference) was estimated from an empirical relationship between Bellani- plate atmometer readings, temperature and extra-terrestrial solar radiation, and then modified by crop coefficients for all crops except pasture. Depending on GCM, projected water demand increased by 12–20% (2010 to 2039), 24–38% (2040 to 2069) and 40–61% (2070 to 2099). Possible elevated CO2 effects on stomatal conductance, which may reduce water demand, were not accounted for. Comparisons with modeled Okanagan Lake inflows indicated that, on average, high water demand and low supply scenarios coincided. In one sub-basin, supply and demand thresholds were exceeded 1 yr in 6 (HadCM3) in the 2050s and at least 1 yr in 4 for all GCMs by the 2080s, and existing water supply infrastructure may be inadequate. Crop growing seasons were defined empirically from growing degree days or threshold temperatures. The growing season lengthened up to 30–35% leading to higher demand in fall and shortages due to low stream flows. Key words: Evapotranspiration, growing degree days, growing season, GIS, PRISM

Response of bacteriophage T7 biological dosimeter to dehydration and extraterrestrial solar UV radiation

The experiment “Phage and uracil response” (PUR) will be accommodated in the EXPOSE facility of the ISS. Bacteriophage T7/isolated T7 DNA will be exposed to different subsets of extreme environmental parameters in space, in order to study the Responses of Organisms to the Space Environment (ROSE). Launch into orbit is preceded by EXPOSE Experiment Verification Tests (EVT) to optimize the methods and the evaluation. Bacteriophage T7/isolated T7 DNA thin layers were exposed to vacuum ( 10 - 6 Pa ), to monochromatic (254 nm) and polychromatic (200–400 nm) UV radiation in air as well as in simulated space vacuum. Using neutral density (ND) filters dose-effect curves were performed in order to define the maximum doses tolerated. The effect of temperature fluctuation in vacuum was also studied. The structural/chemical effects on bacteriophage T7/isolated T7 DNA were analyzed by spectroscopic and microscopical methods. Characteristic changes in the absorption spectrum and in the electrophoretic pattern of phage/DNA have been detected indicating the damage of isolated and intraphage DNA. DNA damage was also determined by quantitative PCR (QPCR) using 555 and 3826 bp fragments of T7 DNA. We obtained substantial evidence that DNA lesions (e.g. strand breaks, DNA-protein cross-links, cyclobutane pirimidine dimers (CPDs) etc.) accumulate throughout exposure. Preliminary results suggest a synergistic action of space vacuum and UV radiation with DNA being the critical target.

Analytical integrated functions for daily solar radiation on slopes

This paper presents a procedure for estimating daily global solar radiation for inclined surfaces having specified slope and aspect for application with surface energy balance models for determining evapotranspiration. Procedures are provided for developing clear sky solar curves and for translating measured solar radiation from a horizontal surface to slopes. The procedure assumes an extensive surface having uniform slope at each point of calculation, so effects of protruding surrounding terrain are not considered. This simplification of terrain aids the application of the procedure within image processing models used for surface energy balance and evapotranspiration calculations, allows the use of a purely analytical solution, which is useful for some types of software, and provides sufficiently accurate results for terrain having gradual to moderate changes in slope. Extraterrestrial solar radiation is computed using an analytical solution for 24-h periods. New developments reported here include a detailed procedure for determining integration limits for the analytical solution that applies to all combinations of slope, aspect and latitude, including steep polar facing slopes where the sun may appear twice per day. Use of clear sky transmissivity procedures from ASCE-EWRI that calculate direct beam and diffuse radiation components separately as a function of elevation, sun angle and precipitable water reduces or eliminates the need for local calibration. Other developments include an improved function describing the reduction in hemispherical diffuse radiation with slope and adjustment of mean daily beam transmissivity using a weighted mean daily solar elevation. Simulated clear sky solar radiation envelope curves and translated measured solar radiation compare well with measurements from two locations in the U.S. over a range of slope and aspect.

A critical review on the estimation of daily global solar radiation from sunshine duration

Abstract Models such as the Angstrom–Prescott equation are used to estimate global solar radiation from sunshine duration. In the literature, researchers investigate either the goodness of the model itself or the goodness of the estimation of global solar radiation based on a set of statistical parameters such as R2, RMSE, MBE, MABE, MPE and MAPE. If the former is the objective, then the statistical analysis should naturally be based on H/Ho − S/So (the ratio of daily solar radiation to extraterrestrial daily solar radiation vs. the ratio of sunshine duration to day length). If the latter is investigated, then the statistical analysis should be based on Hc − Hm (calculated daily solar radiation vs. measured daily solar radiation). A literature survey undertaken in the present article showed that these two data sets are apt to be confused, drawing the statistical parameters to be used in assessment of the estimation model from the latter data set or the vice versa set. The statistical parameters are clearly derived from the basics for both of the data sets, and the inconsistencies caused by this confusion and other factors are exposed. A case study of the estimation models and global solar radiation estimation from sunshine duration is presented using five different models (linear, quadratic, cubic, logarithmic and exponential), which are the most common models used in the literature, based on 6 years long measured hourly global solar radiation data.

Distributed Modeling of Extraterrestrial Solar Radiation over Rugged Terrain

Based on DEM (digital elevation model) data, a distributed model for calculating extraterrestrial solar radiation (ESR) over rugged terrain is developed. This model gives an all-sided consideration on factors influencing ESR. Besides, by merely taking the DEM data as input, it is able to process mass of data and is applicable to satellite image processing platforms or GIS (Geographic Information System). Using DEM data as the general characterization of terrain, ESR quantity with resolution of 1km × 1km for the rugged terrain of China is calculated. Results suggest that annual ESR quantity has clearly (1) a latitude-dependent variation characteristics and a progressive increase trend from north to south; (2) azonal distribution characteristics of annual ESR quantity in mountainous areas arise owing to the effects of topographical factors such as aspect, slope and terrain inter-shielding. The calculated ESR of China in this study can be employed as basic geographic data for relevant studies as well.

A software component for estimating solar radiation

GSRad (global solar radiation) is a software component containing models to estimate extra-terrestrial and ground-level solar radiation (global and photosynthetically active; direct, diffuse, and reflected components) from alternative methods. Radiation data are estimated as either 1-h or 24-h values. Moreover, GSRad provides methods to compute clear sky transmissivity, slope and aspect angles of tilted terrains from a grid of elevation points, and geometric factors to convert radiation estimates from horizontal to non-horizontal surfaces. The component is released as .NET assemblies, allowing the development of clients under Windows operating systems using one of the .NET languages. The component design allows extending the computing capabilities of GSRad without requiring its re-compilation. Examples of clients developed in C# are provided as source code. The component is available for free download, along with an extensive hypertext help.

Correlation of global solar radiation with common geographical and meteorological parameters for Damascus province, Syria

In this study, the effect of geographical and meteorological parameters on the monthly mean daily global solar radiation in Damascus was investigated. With measured data of global solar radiation and the relevant data of astronomical, geographical, geometrical and meteorological parameters for Damascus province, an attempt has been made to correlate the monthly mean daily global solar radiation on a horizontal surface with seven different variables; mean daily extraterrestrial solar radiation intensity I¯0, average daily ratio of sunshine duration n¯/N¯, mean daily relative humidity ϕ¯, mean daily maximum air temperature ϑ¯max, mean daily maximum dew point temperature ϑ¯d,max, mean daily atmospheric pressure P¯ and sine of the solar declination angle sin δ. A new multiple regression relation giving accurate estimates of monthly mean daily global solar radiation on a horizontal surface was suggested. It has a high coefficient of correlation R = 0.9915. The results showed that the suggested model can estimate the global solar radiation within relative errors e of −6.37% and 8.27%. The values of MBD (0.1 W/m2) and also RMSD (229 W/m2) are within acceptable ranges. The global solar radiation intensity values produced by this approach can be used in the design and estimation of the performance of solar applications. It is believed that the model developed in this work is applicable for estimating the monthly mean daily global solar radiation on a horizontal surface at any site in Damascus province, Syria.

Estimating Hourly Direct and Diffuse Solar Radiation for the Compilation of Solar Radiation Distribution Maps

This paper presents a new method for estimating hourly direct and diffuse solar radiation. The essence of the method is the estimation of two important factors related to solar radiation, atmospheric transmittance and a dimensionless parameter, using empirical and physical equations and data from general meteorological observation stations. An equation for atmospheric transmittance of direct solar radiation and a dimensionless parameter representing diffuse solar radiation are developed. The equation is based on multiple regression analysis and uses three parameters as explanatory variates: calculated hourly extraterrestrial solar radiation on a horizontal plane, observed hourly sunshine duration and hourly precipitation as observed at a local meteorological observatory. The dimensionless parameter for estimating a diffuse solar radiation is then determined by linear least squares using observed hourly solar radiation at a local meteorological observatory. The estimated root mean square error (RMSE) of hourly direct and diffuse solar radiation is about 0.0∼0.2 MJ·m-2·h-1 in each mean period. The RMSE of the ten-day and monthly means of these quantities is about 0.0∼0.2 MJ·m-2·h-1, based on comparisons with AMeDAS station data, located at a distance of 6 km.

Analysis of 40 year records of solar radiation data in Shanghai, Nanjing and Hangzhou in Eastern China

In this paper, we analyze global, direct and diffuse solar radiation data on a horizontal surface observed at stations in Shanghai, Nanjing and Hangzhou for the period of 1961 to 2000. The data include monthly averages of the daily clearness index (G/G0: the ratio of global to extraterrestrial solar radiation) and the diffuse fraction (D/G: the ratio of diffuse to global solar radiation. The present study has processed and analyzed the data, including variables or statistics of mean, and annual monthly and daily total, the diurnal variation and the frequency of daily totals of global solar radiation. A correlation between daily values of clearness index and diffuse fraction is obtained and recommended correlation equations were calculated. The annual variations and trend of yearly series are analyzed for daily global, direct and diffuse radiation on a horizontal surface, as well as for daily clearness index and diffuse fraction in Shanghai, Nanjing and Hangzhou. The results show: 1) the east China is characterized by a decrease in global and direct radiation and a little increase in diffuse radiation and a negative linear relationship was obtained between clearness index and diffuse fraction. 2) The annual variations of global, direct and diffuse radiation for Shanghai, Nanjing and Hangzhou are similar with relative low values of global and direct radiation in June due to the Meiyu period. 3) The acceleration of air pollution and decrease of relative sunshine are the possible causes for the decrease of global and direct radiation.