Variability of Ground-Level Ultraviolet: Model and Measurement

Outer, P. N. den; Slaper, H.; Matthijsen, J.; Reinen, H. A. J. M.; Tax, Rick

doi:10.1093/oxfordjournals.rpd.a033174

Cited by 26 publications

(14 citation statements)

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“…The two‐stream model has been used in a model intercomparison and the biologically weighted UV irradiance was within 3% of the benchmark value for high sun (SZA < 35 degrees) and within 7% for low sun (SZA 65–70 degrees) [ van Weele et al , 2000]. Using ground‐based input data the two‐stream model results have been shown to compare well with ground‐based UV measurements at Bilthoven [ den Outer et al , 2000]. A full description of the RIVM‐methodology for UV mapping is described by Slaper et al [2001].…”

Section: Methodsmentioning

confidence: 99%

Assessment of four methods to estimate surface UV radiation using satellite data, by comparison with ground measurements from four stations in Europe

et al. 2002

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[1] Four different satellite-UV mapping methods are assessed by comparing them against ground-based measurements. The study includes most of the variability found in geographical, meteorological and atmospheric conditions. Three of the methods did not show any significant systematic bias, except during snow cover. The mean difference (bias) in daily doses for the Rijksinstituut voor Volksgezondheid en Milieu (RIVM) and Joint Research Centre (JRC) methods was found to be less than 10% with a RMS difference of the order of 30%. The Deutsches Zentrum für Luft-und Raumfahrt (DLR) method was assessed for a few selected months, and the accuracy was similar to the RIVM and JRC methods. It was additionally used to demonstrate how spatial averaging of high-resolution cloud data improves the estimation of UV daily doses. For the Institut d'Aéronomie Spatiale de Belgique (IASB) method the differences were somewhat higher, because of their original cloud algorithm. The mean difference in daily doses for IASB was about 30% or more, depending on the station, while the RMS difference was about 60%. The cloud algorithm of IASB has been replaced recently, and as a result the accuracy of the IASB method has improved. Evidence is found that further research and development should focus on the improvement of the cloud parameterization. Estimation of daily exposures is likely to be improved if additional time-resolved cloudiness information is available for the satellite-based methods. It is also demonstrated that further development work should be carried out on the treatment of albedo of snow-covered surfaces.

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Section: Methodsmentioning

confidence: 99%

Assessment of four methods to estimate surface UV radiation using satellite data, by comparison with ground measurements from four stations in Europe

et al. 2002

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“…The clear‐sky GR is obtained from an empirical relationship based on clear‐sky measurements taken at three different locations across Europe: Thessaloniki (Greece), Garmisch‐Partenkirchen (Germany) and Bilthoven (Netherlands). The relationship, implementing only the SZA, resembles the extinction of direct sunlight through a 60‐km effective atmosphere curved around the Earth's surface [ den Outer et al , 2000].…”

Section: Modeling Uv Radiationmentioning

confidence: 99%

“…Long‐term variations of the UV‐B doses have been analyzed for three European sites, based on spectrally measured UV and reconstructed UV data using linear relationships between the cloud‐induced reduction of GR and that of UV for daily doses [ Kaurola et al , 2000]. We have established an SZA dependency in the relationship between the reduction of GR and of UV daily doses [ den Outer et al , 2000]. A similar SZA dependency was also adapted by Krzyscin et al [2003] to describe 2 years of data at Belsk, Poland.…”

Section: Introductionmentioning

confidence: 99%

UV radiation in the Netherlands: Assessing long‐term variability and trends in relation to ozone and clouds

2005

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[1] The variability and long-term changes in the ultraviolet (UV) climate in the Netherlands have been studied in relation to ozone and clouds, by analyzing modeled and measured values for daily, monthly, and yearly integrated erythemally weighted UV doses. At Bilthoven, Netherlands (longitude 5.19°E, latitude 52.12°N), UV irradiance measurements for the 1994-2003 period yielded a mean annual dose of 447 ± 29 kJ/m 2 and a mean daily dose of 2.5 ± 0.5 kJ/m 2 for June and July. On average, the maximum UV index exceeded 6.5 (i.e., 0.1625 W/m 2 erythemally weighted) on 10 days per year (21 days in 2003). The mean value of measured-to-modeled ratios of erythemal UV irradiances was 1.00 with a standard deviation of 0.06 for days when the measured global solar radiation agrees within 5% with the cloudless sky value. Three previously introduced approaches to model cloud effects on UV doses were shown to have limitations when applied for low Sun and/or optically thick clouds, while a new approach provided the most consistent results with an average ratio of the measured-to-modeled daily doses of 1.02 and a standard deviation of 0.09, for all seasons and weather conditions for the period 1994-2002. Further analysis also revealed a wavelength dependency of the correlation between global solar radiation and UV radiation. Clouds, on average, reduced the daily dose of erythemal UV to 68% of the clear-sky value, whereas for global solar radiation this was 57%. The modeled annual erythemal UV dose was 622 kJ/m

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“…These studies found that the UV reduction factor, i.e., the ratio of UV irradiance to its clear-sky value, could be represented by a non-linear function of the global radiation reduction factor and the solar zenith angle. Several studies (e.g., Foyo-Moreno et al, 1999;den Outer et al, 2000;Matthijsen et al, 2000;McArthur et al, 1999;Fioletov et al, 2001) have suggested empirical parametrizations to derive spectrally integrated characteristics of UV irradiance from pyranometer measurements.…”

Section: Modelsmentioning

confidence: 99%

Climatology and trends of surface UV radiation: Survey article

Tarasick¹,

Fioletov

Wardle

et al. 2003

Atmosphere-Ocean

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An improved understanding of the global ultraviolet (UV) climate has recently become of great interest. A number of stations are now making regular measurements of spectrally-resolved UV-B irradiance. Despite the lack of long-term records RÉSUMÉ [traduit par la rédaction] On cherche récemment à améliorer nos connaissances de la climatologie mondiale de l'ultraviolet (UV). Plusieurs stations mesurent périodiquement l'irradiance UV-B résolue spectralement. Malgré la pénurie de données à long terme, il est possible de décrire la climatologie à court terme de l'irradiance UV-B au sol ainsi que plusieurs de ses caractéristiques et des facteurs dont elle dépend. Le présent article décrit l'état actuel des mesures des UV-B et présente une climatologie de l'irradiance UV-B au sol, notamment pour le Canada. L'irradiance UV est fonction de l'ozone et d'autres variables climatiques; cette relation est examinée en détail en faisant appel aux observations. Une comparaison des résultats fournis par les modèles de transfert radiatif et des mesures récentes révèle qu'il est possible d'inférer l'irradiance UV-B à la surface à partir d'enregistrements plus anciens de l'ozone total et de mesures accessoires (irradiance avec IntroductionThe ultraviolet (UV) solar spectrum is, by common convention, divided into three regions. Solar radiation of less than 280 nm wavelength (the UV-C region) is so strongly absorbed by ozone and (at shorter wavelengths) molecular oxygen that it is undetectable at the Earth's surface. Surface UV irradiance † therefore consists of UV-A (315-400 nm) and UV-B (280-315 nm). While the former comprises a much larger portion of the total solar energy (7% of the extraterrestrial solar constant versus 1.5% for the UV-B portion) it has much less capacity to affect biological systems because the individual photons themselves are less energetic.

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Variability of Ground-Level Ultraviolet: Model and Measurement

Cited by 26 publications

References 0 publications

Assessment of four methods to estimate surface UV radiation using satellite data, by comparison with ground measurements from four stations in Europe

Assessment of four methods to estimate surface UV radiation using satellite data, by comparison with ground measurements from four stations in Europe

UV radiation in the Netherlands: Assessing long‐term variability and trends in relation to ozone and clouds

Climatology and trends of surface UV radiation: Survey article

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