Modelling solar UV radiation in the past: comparison of algorithms and input data

Koepke, Peter; Backer, H. De; Bais, A. F.; Curylo, Aleksander; Eerme, K.; Feister, Uwe; Johnsen, Bjørn; Junk, Jürgen; Kazantzidis, Andreas; Krzyścin, Janusz W.; Lindfors, Anders V.; Olseth, Jan Asle; Outer, Peter den; Pribullová, A.; Schmalwieser, Alois W.; Slaper, H.; Staiger, Henning; Verdebout, J.; Vuilleumier, Laurent; Weihs, Philipp

doi:10.1117/12.687682

Cited by 28 publications

(28 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies showed that the sunshine duration was a worse proxy for a parameterization of the cloud attenuation when compared to the global solar radiation. Using global solar irradiance is more appropriate to parameterize cloud effects on UV (Koepke et al, 2006). However, this variable was measured at Hornsund in some disjointed periods since 1983 but the pyranometer data were not calibrated by a higherranking instrument.…”

Section: Discussionmentioning

confidence: 99%

“…Past variations of the surface erythemal radiation in periods without UV measurements could be retrieved from statistical and radiative transfer modelling using various proxies to describe attenuation of UV radiation in the atmosphere (e.g., Lindfors and Vuilleumier, 2005;Koepke et al, 2006;Lindfors et al, 2007;Rieder et al, 2008). Global solar radiation, cloud cover, solar zenith angle, and the sunshine duration were usually used as proxies to construct empirical formulas to determine cloud attenuation of UV radiation.…”

Section: Data Reconstructionmentioning

confidence: 99%

See 1 more Smart Citation

Trends in erythemal doses at the Polish Polar Station, Hornsund, Svalbard based on the homogenized measurements (1996–2016) and reconstructed data (1983–1995)

Krzyścin

Sobolewski

2018

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Erythemal daily doses measured at the Polish Polar Station, Hornsund (77 • 00 N, 15 • 33 E), for the periods 1996-2001 and 2005-2016 are homogenized using yearly calibration constants derived from the comparison of observed doses for cloudless conditions with the corresponding doses calculated by radiative transfer (RT) simulations. Modeled all-sky doses are calculated by the multiplication of cloudless RT doses by the empirical cloud modification factor dependent on the daily sunshine duration. An all-sky model is built using daily erythemal doses measured in the period 2005-2006-2007. The model is verified by comparisons with the 1996-1997-1998 and 2009-2010-2011 measured data. The daily doses since 1983 (beginning of the proxy data) are reconstructed using the all-sky model with the historical data of the column ozone from satellite measurements (SBUV merged ozone data set), the snow depth (for ground albedo estimation), and the observed daily sunshine duration at the site. Trend analyses of the monthly and yearly time series comprised of the reconstructed and observed doses do not reveal a statistically significant trend in the period 1983-2016. The trends based on the observed data only (1996-2001 and 2005-2016) show declining tendency (about −1 % per year) in the monthly mean of daily erythemal doses in May and June, and in the yearly sum of daily erythemal doses. An analysis of sources of the yearly dose variability since 1983 shows that cloud cover changes are a basic driver of the long-term UV changes at the site.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Data Reconstructionmentioning

confidence: 99%

Trends in erythemal doses at the Polish Polar Station, Hornsund, Svalbard based on the homogenized measurements (1996–2016) and reconstructed data (1983–1995)

Krzyścin

Sobolewski

2018

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Distance between points on Taylor diagram is equal to the centered pattern RMS difference, i.e., RMS of differences having the mean values subtracted from the compared samples. Thus, if we compare behavior of various models (such as ozone content in Umkehr layers by different retrievals) the best correspondence will be found for the point being the closest to the perfect agreement point (f = 0, radius = 1) [e.g., Koepke et al, 2006;Krzyścin and Rajewska-Więch, 2007].…”

Section: D15s09mentioning

confidence: 99%

Comparison of ozone profiles by the Umkehr measurements taken at Belsk (52°N, 21°E) with the Aura Microwave Limb Sounder overpasses: 2004–2006

et al. 2008

View full text Add to dashboard Cite

[1] A comparison of ozone profile measurements by the Umkehr observations taken at Belsk (52°N, 21°E) by the Dobson spectrophotometer and collocated Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura platform during 2004-2006 site overpasses is presented. The MLS ozone vertical profiles from 1.5 and 2.2 retrieval algorithms and various Umkehr retrievals are considered. There is a good agreement between the ozone content in Umkehr layers. The mean difference $ ±5%, standard deviation of the relative differences < 10%, and the correlation coefficient > 0.5 are found in the midstratosphere (Umkehr layers 5-7) and in the upper stratosphere (combined layers 8, 9, and 10). In the lower stratosphere (combined layers 2 and 3 and layer 4) the mean difference and/or standard deviation are larger but the correlation coefficient is still high ($0.8). Ozone content in Umkehr layers by integration of MLS version 1.5 and 2.2 ozone mixing ratio profiles behaves very similarly in the comparisons with the ground-based data.

show abstract

“…The COST-726 modelling exercise (Koepke et al, 2006) has revealed that the SSA retrieved from GADS is too high for Thessaloniki, decisively influenced by urban aerosols. Thus, the SSA is fixed at 0.83 based on Bais et al (2005).…”

Section: Observational Datamentioning

confidence: 99%

Hourly resolved cloud modification factors in the ultraviolet

et al. 2008

Self Cite

View full text Add to dashboard Cite

Abstract. Cloud impacts on the transfer of ultraviolet (UV) radiation through the atmosphere can be assessed by using a cloud modification factor (CMF). CMF, which is based on total global solar irradiation (SOL CMF), has proved to be a solid basis to derive CMFs for the UV radiation (UV CMF). This is an advantage, because total global irradiance, the basis for SOL CMF, is frequently measured and forecasted by numerical weather prediction systems and includes all relevant effects for radiation transmission, such as cloud optical depth, different cloud layers, multiple reflection, as well as the distinct difference as to whether the solar disc is obscured by clouds or not. In the UV range clouds decrease the irradiance to a lesser extent than in the visible and infrared spectral range. Thus the relationship between CMFs for solar radiation and for UV-radiation is not straight forward, but will depend on whether, for example, the solar zenith angle (SZA) and wavelength band or action spectrum in the UV have been taken into consideration. Den Outer et al. provide a UV CMF algorithm on a daily basis, which accounts for these influences. It requires as input a daily SOL CMF and the SZA at noon. The calculation of SOL CMF uses the clear-sky algorithm of the European Solar Radiation Atlas to account for varying turbidity impacts. The algorithm's capability to derive hourly UV CMFs based on the SZA at the corresponding hour and its worldwide applicability is validated for erythemal UV using observational data retrieved from the databases of the COST-Action 726 on "Long-termCorrespondence to: H. Staiger (henning.staiger@gmx.de) changes and climatology of UV radiation over Europe" and the USDA UVB Monitoring Program. The clear-sky part of the models has proved to be of good quality. Accumulated to daily doses it forms a tight cluster of points to the highest measured daily sums. All sky model performances for hourly resolution are shown to be comparable in accuracy with the well performing daily models of the COST-726 model intercomparison.

show abstract

Modelling solar UV radiation in the past: comparison of algorithms and input data

Cited by 28 publications

References 3 publications

Trends in erythemal doses at the Polish Polar Station, Hornsund, Svalbard based on the homogenized measurements (1996–2016) and reconstructed data (1983–1995)

Trends in erythemal doses at the Polish Polar Station, Hornsund, Svalbard based on the homogenized measurements (1996–2016) and reconstructed data (1983–1995)

Comparison of ozone profiles by the Umkehr measurements taken at Belsk (52°N, 21°E) with the Aura Microwave Limb Sounder overpasses: 2004–2006

Hourly resolved cloud modification factors in the ultraviolet

Contact Info

Product

Resources

About