Modelling of UV radiation variations at different time scales

Borkowski, J.

doi:10.5194/angeo-26-441-2008

Cited by 13 publications

(8 citation statements)

References 16 publications

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“…The levels of the UV radiation could vary significantly in the past due to large long-term variations of the atmospheric parameters. The several UV dose reconstruction studies were performed during the last decade (Trepte and Winkler 2004;Lindfors and Vuilleumier 2005;Borkowski 2008;Hu et al 2010;Paulescu et al 2010 etc.). They are based on the radiative transfer model calculations, statistical modeling, and hybrid models, combining radiative transfer model calculations with the empirical estimates of the influence of various factors on the UV radiation (Borkowski 2008).…”

Section: Introductionmentioning

confidence: 99%

Reconstruction of the erythemal UV radiation data in Novi Sad (Serbia) using the NEOPLANTA parametric model

Malinović-Milićević

Mihailoviĉ

Radovanović

2014

Theor Appl Climatol

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This paper focuses on the development and application of a technique for filling the daily erythemal UV dose data gaps and the reconstruction of the past daily erythemal UV doses in Novi Sad, Serbia. The technique implies developing the empirical equation for estimation of daily erythemal UV doses by means of relative daily sunshine duration under all sky conditions. A good agreement was found between modeled and measured values of erythemal UV doses. This technique was used for filling the short gaps in the erythemal UV dose measurement series (2003)(2004)(2005)(2006)(2007)(2008)(2009) as well as for the reconstruction of the past time-series values . Statistically significant positive erythemal UV dose trend of 6.9 J m −2 per year was found during the period 1981-2009. In relation to the reference period 1981-1989, an increase in the erythemal UV dose of 6.92 % is visible in the period 1990-1999 and the increase of 9.67 % can be seen in the period 2000-2009. The strongest increase in erythemal UV doses has been found for winter and spring seasons.

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Section: Introductionmentioning

confidence: 99%

Reconstruction of the erythemal UV radiation data in Novi Sad (Serbia) using the NEOPLANTA parametric model

Malinović-Milićević

Mihailoviĉ

Radovanović

2014

Theor Appl Climatol

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“…The relationship between UV and global solar radiation and its dependence on total ozone column, cloudiness or aerosol was analysed, e.g. by Antón et al (2008) and Borkowski (2008).…”

Section: Introductionmentioning

confidence: 99%

Empirical models of UV total radiation and cloud effect study

Mateos

Miguel

Bilbao

2009

Intl Journal of Climatology

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Several empirical models of hourly ultraviolet total radiation (UVT) have been proposed in this study. Measurements of UVT radiation, 290-385 nm, have been recorded at ground level from February 2001 to June 2008 in Valladolid, Spain (latitude 41°40 N, longitude 4°50 W and 840 m a.s.l.). The empirical models have emerged due to the lack of some radiometric variables in measuring stations. Hence, good forecasts of them can be obtained from usual measures in these stations. Therefore, some advantages of the empirical models are that they allow the estimation of past missing data in the database and the forecast of future ultraviolet solar availability. In this study, reported models in the bibliography have been assessed and recalibrated. New expressions have been proposed that allow obtaining hourly values of ultraviolet radiation from global radiation measures and parameters as clearness index and relative optical air mass. The accuracy of these models has been assessed through the following statistical indices: mean bias, mean-absolute bias and root-mean-square errors whose values are close to zero, below 7% and below 10%, respectively. Two new clear sky models have been used to evaluate two new parameters: ultraviolet and global cloud modification factors, which can help to understand the role of the clouds on solar radiation. The ultraviolet cloud modification factor depends on cloudiness in such a way that its value under overcast skies is half of the cloudless skies one. Exponential and potential fits are the best relationships between both cloud factors. Finally, these parameters have been used to build new UV empirical models which show low values of the statistical indices mentioned above.

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“…Trend studies of surface UV radiation levels are complex due to changes in many factors contributing to the surface UV levels. Additionally are long-term observations of ground-based UV levels limited; no data records longer than Belsk (1976) (Borkowski, 2008) and Norrkoping (1983) (Josefsson, 2006) are published, both showing a positive trend for the investigated period. An overview and further details on observed and reconstructed UV trends are discussed in the section below.…”

Section: Introductionmentioning

confidence: 99%

Extensive reduction of surface UV radiation since 1750 in world's populated regions

Kvalevåg

Myhre

2009

Atmos. Chem. Phys.

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Abstract. Human activity influences a wide range of components that affect the surface UV radiation levels, among them ozone at high latitudes. We calculate the effect of human-induced changes in the surface erythemally weighted ultra-violet radiation (UV-E) since 1750. We compare results from a radiative transfer model to surface UV-E radiation for year 2000 derived by satellite observations (from Total Ozone Mapping Spectroradiometer) and to ground based measurements at 14 sites. The model correlates well with the observations; the correlation coefficients are 0.97 and 0.98 for satellite and ground based measurements, respectively. In addition to the effect of changes in ozone, we also investigate the effect of changes in SO 2 , NO 2 , the direct and indirect effects of aerosols, albedo changes and aviation-induced contrails and cirrus. The results show an increase of surface UV-E in polar regions, most strongly in the Southern Hemisphere. Furthermore, our study also shows an extensive surface UV-E reduction over most land areas; a reduction up to 20% since 1750 is found in some industrialized regions. This reduction in UV-E over the industrial period is particularly large in highly populated regions.

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Modelling of UV radiation variations at different time scales

Cited by 13 publications

References 16 publications

Reconstruction of the erythemal UV radiation data in Novi Sad (Serbia) using the NEOPLANTA parametric model

Reconstruction of the erythemal UV radiation data in Novi Sad (Serbia) using the NEOPLANTA parametric model

Empirical models of UV total radiation and cloud effect study

Extensive reduction of surface UV radiation since 1750 in world's populated regions

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