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A compact array spectroradiometer that enables precise and robust measurements of solar UV spectral direct irradiance is presented. We show that this instrument can retrieve total ozone column (TOC) accurately. The internal stray light, which is often the limiting factor for measurements in the UV spectral range and increases the uncertainty for TOC analysis, is physically reduced so that no other stray-light reduction methods, such as mathematical corrections, are necessary. The instrument has been extensively characterised at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. During an international total ozone measurement intercomparison at the Izaña Atmospheric Observatory in Tenerife, the high-quality applicability of the instrument was verified with measurements of the direct solar irradiance and subsequent TOC evaluations based on the spectral data measured between 12 and 30 September 2016. The results showed deviations of the TOC of less than 1.5 % from most other instruments in most situations and not exceeding 3 % from established TOC measurement systems such as Dobson or Brewer.
Ralf Zuber; Peter Sperfeld; Stefan Riechelmann; Saulius Nevas; Meelis Sildoja; Gunther Seckmeyer. Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range. Atmospheric Measurement Techniques 2018, 11, 2477 -2484.
AMA StyleRalf Zuber, Peter Sperfeld, Stefan Riechelmann, Saulius Nevas, Meelis Sildoja, Gunther Seckmeyer. Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range. Atmospheric Measurement Techniques. 2018; 11 (4):2477-2484.
Chicago/Turabian StyleRalf Zuber; Peter Sperfeld; Stefan Riechelmann; Saulius Nevas; Meelis Sildoja; Gunther Seckmeyer. 2018. "Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range." Atmospheric Measurement Techniques 11, no. 4: 2477-2484.
This work assesses the performance of five transposition models that estimate the global and diffuse solar irradiance on tilted planes based on the global horizontal irradiance. The modelled tilted irradiance values are compared to measured one-minute values from pyranometers and silicon sensors tilted at different angles at Hannover (Germany) and NREL (Golden, CO, USA). It can be recognized that the deviations of the model of Liu and Jordan, Klucher and Perez from the measurements increases as the tilt angle increases and as the sensors are oriented away from the south direction, where they receive lower direct radiation than south-oriented surfaces. Accordingly, the vertical E, W and N planes show the highest deviation. Best results are found by the models from Hay and Davies and Reindl, when horizontal pyranometer measurements and a constant albedo value of 0.2 are used. The relative root mean squared difference (rRMSD) of the anisotropic models does not exceed 11% for south orientation and low inclination angles (β = 10–60°), but reaches up to 28.9% at vertical planes. For sunny locations such as Golden, the Perez model provides the best estimates of global tilted irradiance for south-facing surfaces. The relative mean absolute difference (rMAD) of the Perez model at NREL ranges from 4.2% for 40° tilt to 8.7% for 90° tilt angle, when horizontal pyranometer measurements and a measured albedo value are used; the use of measured albedo values instead of a constant value of 0.2 leads to a reduction of the deviation to 3.9% and 6.0%, respectively. The use of higher albedo values leads to a significant increase of rMAD. We also investigated the uncertainty resulting from using horizontal pyranometer measurements, in combination with constant albedo values, to estimate the incident irradiance on tilted photovoltaic (PV) modules. We found that these uncertainties are small or negligible.
Riyad Mubarak; Martin Hofmann; Stefan Riechelmann; Gunther Seckmeyer. Comparison of Modelled and Measured Tilted Solar Irradiance for Photovoltaic Applications. Energies 2017, 10, 1688 .
AMA StyleRiyad Mubarak, Martin Hofmann, Stefan Riechelmann, Gunther Seckmeyer. Comparison of Modelled and Measured Tilted Solar Irradiance for Photovoltaic Applications. Energies. 2017; 10 (11):1688.
Chicago/Turabian StyleRiyad Mubarak; Martin Hofmann; Stefan Riechelmann; Gunther Seckmeyer. 2017. "Comparison of Modelled and Measured Tilted Solar Irradiance for Photovoltaic Applications." Energies 10, no. 11: 1688.
A compact array spectroradiometer technology that enables precise and robust measurements of UV spectral irradiance is presented. The spectroradiometer design allows various applications such as measurement of high-power UV lamps, risk assessment of sources and measurement of solar irradiance. We show that this technology can perform precise total ozone column (TOC) retrieval. The internal stray light, which is often the limiting factor for measurements in the UV spectral range and increases the uncertainty for TOC analysis significantly, is physically reduced so that no other stray light 15 reduction methods, such as mathematical corrections, are necessary. The instrument and its elaborate components have been extensively characterised at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. During an international total ozone measurement intercomparison at the Izaña observatory in Tenerife, the high-quality applicability of the instrument was verified with measurements of the direct solar irradiance and subsequent TOC evaluations based on the spectral data between 12 and 30 September 2016. The results showed deviations of less than 1.5 % to most other instruments in most 20 situations not exceeding 3 % compared to established TOC measurement systems such as Dobson or Brewer.
Ralf Zuber; Peter Sperfeld; Stefan Riechelmann; Saulius Nevas; Meelis Sildoja; Gunther Seckmeyer. Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range. 2017, 2017, 1 -12.
AMA StyleRalf Zuber, Peter Sperfeld, Stefan Riechelmann, Saulius Nevas, Meelis Sildoja, Gunther Seckmeyer. Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range. . 2017; 2017 ():1-12.
Chicago/Turabian StyleRalf Zuber; Peter Sperfeld; Stefan Riechelmann; Saulius Nevas; Meelis Sildoja; Gunther Seckmeyer. 2017. "Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range." 2017, no. : 1-12.
In a recent study, melanoma incidence rates for Austrian inhabitants living at higher altitudes were found to increase by as much as 30% per 100 m altitude. This strong increase cannot simply be explained by the known increase of erythemally-weighted irradiance with altitude, which ranges between 0.5% and 4% per 100 m. We assume that the discrepancy is partially explainable by upwelling UV radiation; e.g., reflected by snow-covered surfaces. Therefore, we present an approach where the human UV exposure is derived by integrating incident radiation over the 3D geometry of a human body, which enables us to take upwelling radiation into account. Calculating upwelling and downwelling radiance with a radiative transfer model for a snow-free valley and for snow-covered mountain terrain (with albedo of 0.6) yields an increase in UV exposure by 10% per 100 m altitude. The results imply that upwelling radiation plays a significant role in the increase of melanoma incidence with altitude.
Michael Schrempf; Daniela Haluza; Stana Simic; Stefan Riechelmann; Kathrin Graw; Gunther Seckmeyer. Is Multidirectional UV Exposure Responsible for Increasing Melanoma Prevalence with Altitude? A Hypothesis Based on Calculations with a 3D-Human Exposure Model. International Journal of Environmental Research and Public Health 2016, 13, 961 .
AMA StyleMichael Schrempf, Daniela Haluza, Stana Simic, Stefan Riechelmann, Kathrin Graw, Gunther Seckmeyer. Is Multidirectional UV Exposure Responsible for Increasing Melanoma Prevalence with Altitude? A Hypothesis Based on Calculations with a 3D-Human Exposure Model. International Journal of Environmental Research and Public Health. 2016; 13 (10):961.
Chicago/Turabian StyleMichael Schrempf; Daniela Haluza; Stana Simic; Stefan Riechelmann; Kathrin Graw; Gunther Seckmeyer. 2016. "Is Multidirectional UV Exposure Responsible for Increasing Melanoma Prevalence with Altitude? A Hypothesis Based on Calculations with a 3D-Human Exposure Model." International Journal of Environmental Research and Public Health 13, no. 10: 961.
High resolution global irradiance time series are needed for accurate simulations of photovoltaic (PV) systems, since the typical volatile PV power output induced by fast irradiance changes cannot be simulated properly with commonly available hourly averages of global irradiance. We present a two-step algorithm that is capable of synthesizing one-minute global irradiance time series based on hourly averaged datasets. The algorithm is initialized by deriving characteristic transition probability matrices (TPM) for different weather conditions (cloudless, broken clouds and overcast) from a large number of high resolution measurements. Once initialized, the algorithm is location-independent and capable of synthesizing one-minute values based on hourly averaged global irradiance of any desired location. The one-minute time series are derived by discrete-time Markov chains based on a TPM that matches the weather condition of the input dataset. One-minute time series generated with the presented algorithm are compared with measured high resolution data and show a better agreement compared to two existing synthesizing algorithms in terms of temporal variability and characteristic frequency distributions of global irradiance and clearness index values. A comparison based on measurements performed in Lindenberg, Germany, and Carpentras, France, shows a reduction of the frequency distribution root mean square errors of more than 60% compared to the two existing synthesizing algorithms.
Martin Hofmann; Stefan Riechelmann; Cristian Crisosto; Riyad Mubarak; Gunther Seckmeyer. Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations. International Journal of Photoenergy 2014, 2014, 1 -10.
AMA StyleMartin Hofmann, Stefan Riechelmann, Cristian Crisosto, Riyad Mubarak, Gunther Seckmeyer. Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations. International Journal of Photoenergy. 2014; 2014 ():1-10.
Chicago/Turabian StyleMartin Hofmann; Stefan Riechelmann; Cristian Crisosto; Riyad Mubarak; Gunther Seckmeyer. 2014. "Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations." International Journal of Photoenergy 2014, no. : 1-10.
Chile's northern Atacama Desert has been pointed out as one of the places on earth where the world's highest surface ultraviolet (UV) may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low total ozone column. Aimed at detecting those peak UV levels, we carried out in January 2013 ground-based spectral measurements on the Chajnantor Plateau (5100 m altitude, 23°00′S, 67°45′W) and at the Paranal Observatory (2635 m altitude, 24°37′S, 70°24′W). The UV index computed from our spectral measurements peaked at 20 on the Chajnantor Plateau (under broken cloud conditions) and at 16 at the Paranal Observatory (under cloudless conditions). Spectral measurements carried out in June 2005 at the Izaña Observatory (2367 m altitude, 28°18′N, 16°30′W) were used for further comparisons. Due to the differences in sun–earth separation, total ozone column, altitude, albedo, aerosols and clouds, peak UV levels are expected to be significantly higher at southern hemisphere sites than at their northern hemisphere counterparts.
Raul R. Cordero; Gunther Seckmeyer; Alessandro Damiani; Stefan Riechelmann; Juan Antonio Rayas; Fernando Labbe; David Laroze. The world's highest levels of surface UV. Photochemical & Photobiological Sciences 2014, 13, 70 -81.
AMA StyleRaul R. Cordero, Gunther Seckmeyer, Alessandro Damiani, Stefan Riechelmann, Juan Antonio Rayas, Fernando Labbe, David Laroze. The world's highest levels of surface UV. Photochemical & Photobiological Sciences. 2014; 13 (1):70-81.
Chicago/Turabian StyleRaul R. Cordero; Gunther Seckmeyer; Alessandro Damiani; Stefan Riechelmann; Juan Antonio Rayas; Fernando Labbe; David Laroze. 2014. "The world's highest levels of surface UV." Photochemical & Photobiological Sciences 13, no. 1: 70-81.
Stefan Riechelmann; Michael Schrempf; Gunther Seckmeyer. Simultaneous measurement of spectral sky radiance by a non-scanning multidirectional spectroradiometer (MUDIS). Measurement Science and Technology 2013, 24, 1 .
AMA StyleStefan Riechelmann, Michael Schrempf, Gunther Seckmeyer. Simultaneous measurement of spectral sky radiance by a non-scanning multidirectional spectroradiometer (MUDIS). Measurement Science and Technology. 2013; 24 (12):1.
Chicago/Turabian StyleStefan Riechelmann; Michael Schrempf; Gunther Seckmeyer. 2013. "Simultaneous measurement of spectral sky radiance by a non-scanning multidirectional spectroradiometer (MUDIS)." Measurement Science and Technology 24, no. 12: 1.
We present a novel method to calculate vitamin D3 -weighted exposure by integrating the incident solar spectral radiance over all relevant parts of the human body. Earlier investigations are based on the irradiance on surfaces, whereas our calculated exposure of a voxel model of a human takes into account the complex geometry of the radiation field. Assuming that sufficient vitamin D3 (1000 international units) can be produced within the human body in one minute for a completely uncovered body in vertical posture in summer at midlatitudes (e.g. Rome, June 21, noon, UV index of 10), we calculate the exposure times needed in other situations or seasons to gain enough vitamin D3 . Our calculations show that the UV index is not a good indicator for the exposure which depends on the orientation of the body (e.g. vertical (standing) or horizontal (lying down) posture). Without clothing the exposure is dominated by diffuse sky radiation and it is nearly irrelevant how the body in vertical posture is oriented toward the sun. At the winter solstice (December 21, noon, cloudy) at least in central Europe sufficient vitamin D3 cannot be obtained with realistic clothing, even if the exposure were extended to all daylight hours.
Gunther Seckmeyer; Michael Schrempf; Anna Wieczorek; Stefan Riechelmann; Kathrin Graw; Stefan Seckmeyer; Maria Zankl. A Novel Method to Calculate Solar UV Exposure Relevant to Vitamin D Production in Humans. Photochemistry and Photobiology 2013, 89, 974 -983.
AMA StyleGunther Seckmeyer, Michael Schrempf, Anna Wieczorek, Stefan Riechelmann, Kathrin Graw, Stefan Seckmeyer, Maria Zankl. A Novel Method to Calculate Solar UV Exposure Relevant to Vitamin D Production in Humans. Photochemistry and Photobiology. 2013; 89 (4):974-983.
Chicago/Turabian StyleGunther Seckmeyer; Michael Schrempf; Anna Wieczorek; Stefan Riechelmann; Kathrin Graw; Stefan Seckmeyer; Maria Zankl. 2013. "A Novel Method to Calculate Solar UV Exposure Relevant to Vitamin D Production in Humans." Photochemistry and Photobiology 89, no. 4: 974-983.
We have used data from the Ozone Monitoring Instrument (OMI) aboard NASA's Earth Observing System (EOS) Aura satellite over the period 2004–11 to describe the characteristics of surface ultraviolet (UV) irradiance at Escudero Station (62°12′S, 58°57′W). The station is located on King George Island (northern Antarctic Peninsula). Temperatures in summer are frequently above 0°C, and the surrounding ocean is typically ice-free. We found that the UV irradiance at Escudero is driven by the Antarctic ozone hole (which annually in spring leads to significant variations in the ozone) and by clouds (which are more frequent and have a larger optical depth compared with other Antarctic sites). The combined effect of ozone and clouds led to significant variations in the surface UV. The variability (taken as the standard deviation of the UV estimates retrieved from OMI) is typically greater than 30% at Escudero, but may reach values greater than 50% in spring. The consistency of OMI-derived data was checked by using ground-based spectral measurements carried out under controlled conditions in January 2011.
Raúl R. Cordero; Alessandro Damiani; Gunther Seckmeyer; Stefan Riechelmann; Fernando Labbe; David Laroze; Fernanda Garate. Satellite-derived UV climatology at Escudero Station, Antarctic Peninsula. Antarctic Science 2013, 25, 791 -803.
AMA StyleRaúl R. Cordero, Alessandro Damiani, Gunther Seckmeyer, Stefan Riechelmann, Fernando Labbe, David Laroze, Fernanda Garate. Satellite-derived UV climatology at Escudero Station, Antarctic Peninsula. Antarctic Science. 2013; 25 (6):791-803.
Chicago/Turabian StyleRaúl R. Cordero; Alessandro Damiani; Gunther Seckmeyer; Stefan Riechelmann; Fernando Labbe; David Laroze; Fernanda Garate. 2013. "Satellite-derived UV climatology at Escudero Station, Antarctic Peninsula." Antarctic Science 25, no. 6: 791-803.
We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.
Korntip Tohsing; Michael Schrempf; Stefan Riechelmann; Holger Schilke; Gunther Seckmeyer. Measuring high-resolution sky luminance distributions with a CCD camera. Applied Optics 2013, 52, 1564 -1573.
AMA StyleKorntip Tohsing, Michael Schrempf, Stefan Riechelmann, Holger Schilke, Gunther Seckmeyer. Measuring high-resolution sky luminance distributions with a CCD camera. Applied Optics. 2013; 52 (8):1564-1573.
Chicago/Turabian StyleKorntip Tohsing; Michael Schrempf; Stefan Riechelmann; Holger Schilke; Gunther Seckmeyer. 2013. "Measuring high-resolution sky luminance distributions with a CCD camera." Applied Optics 52, no. 8: 1564-1573.
Raul R Cordero; Gunther Seckmeyer; Stefan Riechelmann; Alessandro Damiani; Fernando Labbe. Monte Carlo-based uncertainty analysis of UV array spectroradiometers. Metrologia 2012, 49, 745 -755.
AMA StyleRaul R Cordero, Gunther Seckmeyer, Stefan Riechelmann, Alessandro Damiani, Fernando Labbe. Monte Carlo-based uncertainty analysis of UV array spectroradiometers. Metrologia. 2012; 49 (6):745-755.
Chicago/Turabian StyleRaul R Cordero; Gunther Seckmeyer; Stefan Riechelmann; Alessandro Damiani; Fernando Labbe. 2012. "Monte Carlo-based uncertainty analysis of UV array spectroradiometers." Metrologia 49, no. 6: 745-755.
Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cut‐off filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be over‐estimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments.
Gunther Seckmeyer; Marcus Klingebiel; Stefan Riechelmann; Insa Lohse; Richard L. McKenzie; J. Ben Liley; Martin W. Allen; Anna-Maria Siani; Giuseppe R. Casale. A Critical Assessment of Two Types of Personal UV Dosimeters. Photochemistry and Photobiology 2011, 88, 215 -222.
AMA StyleGunther Seckmeyer, Marcus Klingebiel, Stefan Riechelmann, Insa Lohse, Richard L. McKenzie, J. Ben Liley, Martin W. Allen, Anna-Maria Siani, Giuseppe R. Casale. A Critical Assessment of Two Types of Personal UV Dosimeters. Photochemistry and Photobiology. 2011; 88 (1):215-222.
Chicago/Turabian StyleGunther Seckmeyer; Marcus Klingebiel; Stefan Riechelmann; Insa Lohse; Richard L. McKenzie; J. Ben Liley; Martin W. Allen; Anna-Maria Siani; Giuseppe R. Casale. 2011. "A Critical Assessment of Two Types of Personal UV Dosimeters." Photochemistry and Photobiology 88, no. 1: 215-222.