UVI (UV Index) is a unitless quantity based on erythema biological spectral weighting function (BSWF), that gives an easy to interpret UV measure, mainly meant for informing general public about sunburn risk.
UVI(spct, std = "NOAA", integer_UVI = FALSE)depending on the argument passed to integer_UVI, a numeric
(FALSE) or integer (TRUE) value for the unitless UVI.
a source.spct object
character One of "WWO", "NOAA".
logical Return a positive integer value according to WWO recommended practice or a numeric value.
Two different definitions of UV Index are implemented in this package. Setting std="NOAA" follows the definition in Kiedron et al. (2007) 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 (see WHO, 2002). "NOAA" is the default as this is safer with noisy data for solar radiation measured at ground level, and in this case the value of UVI should be correct, and almost identical except for errors caused by noise at shorter wavelengths. However, when calculating UVI from radiation spectra from UV lamps, "WMO" should be used, as most UV lamps do emit some radiation between 250 nm and 286.5 nm.
World Health Organization, World Meteorological Organization, United Nations Environment Programme & International Commission on Non-Ionizing Radiation Protection. (2002) Global Solar UV Index: A Practical Guide. World Health Organization, Geneva. ISBN 9241590076. https://apps.who.int/iris/handle/10665/42459
P. Kiedron, S. Stierle and K. Lantz (2007) Instantaneous UV Index and Daily UV Dose Calculations. NOAA-EPA Brewer Network. https://www.esrl.noaa.gov/gmd/grad/neubrew/docs/UVindex.pdf
UVI(sun.spct)
UVI(sun.spct, "WMO")
UVI(sun.spct, integer_UVI = TRUE)
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