CIE as defined by CIE_e_fun but with no option to
change normalization wavelength, and with the wavelength limits adjusted to
those used for UVI. Using std="NOAA" follows the definition in
http://www.esrl.noaa.gov/gmd/grad/neubrew/docs/UVindex.pdf but using
CIE98 as SWF. NOAA definition discards wavelengths shorter than 286.5 nm as
when calculated based on spectral data from Brewer instruments. "WMO" uses
the internationally accepted lower limit at 250 nm. "NOAA" is the default
as this is safer with noisy data for sunlight, and for solar radiation the
value of UVI should be correct. When calculating UVI for radiation spectra
from UV lamps, "WMO" should be used.
UVI_wb(std = "NOAA")P. Kiedron, S. Stierle and K. Lantz (2007) Instantaneous UV Index and Daily UV Dose Calculations. NOAA-EPA Brewer Network. http://www.esrl.noaa.gov/gmd/grad/neubrew/docs/UVindex.pdf
UVI