Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.509 IF 5.509
  • IF 5-year value: 5.689 IF 5-year 5.689
  • CiteScore value: 5.44 CiteScore 5.44
  • SNIP value: 1.519 SNIP 1.519
  • SJR value: 3.032 SJR 3.032
  • IPP value: 5.37 IPP 5.37
  • h5-index value: 86 h5-index 86
  • Scimago H index value: 161 Scimago H index 161
Volume 8, issue 13 | Copyright

Special issue: One century of solar ultraviolet research

Atmos. Chem. Phys., 8, 3369-3383, 2008
https://doi.org/10.5194/acp-8-3369-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

  30 Jun 2008

30 Jun 2008

Quality assurance of the Brewer spectral UV measurements in Finland

K. Lakkala1, A. Arola2, A. Heikkilä2, J. Kaurola2, T. Koskela2, E. Kyrö1, A. Lindfors2, O. Meinander2, A. Tanskanen2, J. Gröbner3, and G. Hülsen3 K. Lakkala et al.
  • 1Finnish Meteorological Institute, Arctic Research Centre, Sodanlylä, Finland
  • 2Finnish Meteorological Institute, Helsinki, Finland
  • 3Physikalisches Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf, Switzerland

Abstract. The quality assurance of the two Brewer spectrophotometers of the Finnish Meteorological Institute is discussed in this paper. The complete data processing chain from raw signal to high quality spectra is presented. The quality assurance includes daily maintenance, laboratory characterizations, calculation of long-term spectral responsivity, data processing and quality assessment. The cosine correction of the measurements is based on a new method, and is included in the data processing software. The results showed that the actual cosine correction factor of the two Finnish Brewers can vary between 1.08–1.13 and 1.08–1.12, respectively, depending on the sky radiance distribution and wavelength. The temperature characterization showed a linear temperature dependence between the instruments' internal temperature and the photon counts per cycle, and a temperature correction was used for correcting the measurements. The long-term spectral responsivity was calculated using the time series of several lamps using two slightly different methods. The long-term spectral responsivity was scaled to the irradiance scale of the Helsinki University of Technology (HUT) for the whole of the measurement time-periods 1990–2006 and 1995–2006 for Sodankylä and Jokioinen, respectively. Both Brewers have participated in many international spectroradiometer comparisons, and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002–2007.

Download & links
Publications Copernicus
Special issue
Download
Citation
Share