UV index climatology over the United States and Canada from ground-based and satellite estimates ...

• Main Authors: Fioletov, V. E., Kimlin, M. G., Krotkov, Nickolay, McArthur, L. J. B., Kerr, J. B., Wardle, D. I., Herman, Jay, Meltzer, R., Mathews, T. W., Kaurola, J.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: AGU 2004
• Subjects: Arctic; Canada
• Online Access: https://dx.doi.org/10.13016/m2cbz8-mtkt; https://mdsoar.org/handle/11603/28603

Long-term monthly mean UV index values for Canada and the United States were calculated using information from two sources: from noon erythemal UV estimated from Total Ozone Mapping Spectrometer (TOMS) total ozone and reflectivity data and from UV index values derived from observations of global solar radiation, total ozone, dew point, and snow cover. The results are presented as monthly maps of mean noon UV index values. Mean UV index values in summer range from 1.5 in the Arctic to 11.5 over southern Texas. Both climatologies were validated against spectral UV irradiance measurements made by Brewer spectrophotometers. With snow on the ground the TOMS-based data underestimate UV by up to 60% with respect to Brewer measurements and UV derived from global solar radiation and other parameters. In summer, TOMS UV index climatology values are from 10 to 30% higher than those derived from global solar radiation and other parameters. The difference is probably related to aerosol absorption and pollution effects in ...