Please use this identifier to cite or link to this item:
Title: Photolysis frequency measurement techniques: results of a comparison within the ACCENT project
Authors: Bohn, B.
Corlett, Gary K.
Gillmann, M.
Sanghavi, S.
Stange, G.
Tensing, E.
Vrekoussis, M.
Bloss, W. J.
Clapp, L. J.
Kortner, M.
Dorn, H-P.
Monks, Paul Steven
Platt, U.
Plass-Dulmer, C.
Mihalopoulos, N.
Heard, D. E.
Clemitshaw, K. C.
Meixner, F. X.
Prevot, A. S. H.
Schmitt, R.
First Published: 10-Sep-2008
Publisher: Copernicus Publications on behalf of the European Geosciences Union
Citation: Atmospheric Chemistry And Physics, 2008, 8 (17), pp. 5373-5391 (19)
Abstract: An intercomparison of different radiometric techniques measuring atmospheric photolysis frequencies j(NO2), j(HCHO) and j(O1D) was carried out in a two-week field campaign in June 2005 at Jülich, Germany. Three double-monochromator based spectroradiometers (DM-SR), three single-monochromator based spectroradiometers with diode-array detectors (SM-SR) and seventeen filter radiometers (FR) (ten j(NO2)-FR, seven j(O1D)-FR) took part in this comparison. For j(NO2), all spectroradiometer results agreed within ±3%. For j(HCHO), agreement was slightly poorer between −8% and +4% of the DM-SR reference result. For the SM-SR deviations were explained by poorer spectral resolutions and lower accuracies caused by decreased sensitivities of the photodiode arrays in a wavelength range below 350 nm. For j(O1D), the results were more complex within +8% and −4% with increasing deviations towards larger solar zenith angles for the SM-SR. The direction and the magnitude of the deviations were dependent on the technique of background determination. All j(NO2)-FR showed good linearity with single calibration factors being sufficient to convert from output voltages to j(NO2). Measurements were feasible until sunset and comparison with previous calibrations showed good long-term stability. For the j(O1D)-FR, conversion from output voltages to j(O1D) needed calibration factors and correction functions considering the influences of total ozone column and elevation of the sun. All instruments showed good linearity at photolysis frequencies exceeding about 10% of maximum values. At larger solar zenith angles, the agreement was non-uniform with deviations explainable by insufficient correction functions. Comparison with previous calibrations for some j(O1D)-FR indicated drifts of calibration factors.
DOI Link: 10.5194/acp-8-5373-2008
ISSN: 1680-7316
eISSN: 1680-7324
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © Author(s) 2008. This work is distributed under the Creative Commons Attribution 3.0 License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

Files in This Item:
File Description SizeFormat 
acp-8-5373-2008.pdfPublished (publisher PDF)3.96 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.