%0 Journal Article
%A Bohn, B.
%A Corlett, G.K.
%A Gillmann, M.
%A Sanghavi, S.
%A Stange, G.
%A Tensing, E.
%A Vrekoussis, M.
%A Bloss, W. J.
%A Clapp, L.J.
%A Kortner, M.
%A Dorn, H.-P.
%A Monks, P. S.
%A Platt, U.
%A Plass-Dülmer, C.
%A Mihalopoulos, N.
%A Heard, D. E.
%A Clemitshaw, K. C.
%A Meixner, F. X.
%A Prevot, A. S. H.
%A Schmitt, R.
%T Photolysis frequency measurement techniques: results of a comparison within the ACCENT project
%J Atmospheric chemistry and physics
%V 8
%@ 1680-7316
%C Katlenburg-Lindau
%I EGU
%M PreJuSER-1445
%P 5373 - 5391
%D 2008
%Z Record converted from VDB: 12.11.2012
%X An intercomparison of different radiometric techniques measuring atmospheric photolysis frequencies j(NO2), j(HCHO) and j((OD)-D-1) was carried out in a two-week field campaign in June 2005 at Julich. 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((OD)-D-1)-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 wave-length range below 350 nm. For j((OD)-D-1), 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 sing-le 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((OD)-D-1)-FR, conversion from output voltages to j((OD)-D-1) 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 sonic J((OD)-D-1)-FR indicated drifts of calibration factors.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000259221400020
%R 10.5194/acp-8-5373-2008
%U https://juser.fz-juelich.de/record/1445