Radiación ultravioleta productora de eritema en Valdivia: comparación entre inferencias satelitales, modelo de transferencia radiativa y mediciones desde tierra / Erythemal ultraviolet radiation in Valdivia: a comparison among satellite data, a radiative transfer model and ground based observations

To evaluate dose rates and daily doses (DDE) at Valdivia in Southern Chile, ultraviolet irradiances recorded every 15 min from 1998 to 2000 with a high resolution spectroradiometer were weighted with an erythemal action spectrum. Exposure times to get one MED (210 J/m2) in Summer are 10, 12, 18 and 24 min for skin types I trough IV respectively. DDE estimations included in NASA Web products overestimate measurements by 16 percent on average in Summer, with an absolute uncertainty of 980 J/m2 at the 95 percent level. Observed dose rates for clear days are in fair agreement with the numerical output from a numerical model, suggesting that acute episodes can be predicted if total ozone can be forecasted and the population is instructed on corrections for cloud effects