A comparison study between the NCAR and CIESIN model calculations of UV erythmal dose and UV index

The calculated values of UV index and UV erythemal dose in Baghdad city with clear sky for certain days of the year with variation solar zenith angles from 0^º to 80^º using the NCAR and CIESIN model and the results have been compared ,the differences between the two models out put have been evaluated. The results of the CIESIN model show good agreement with NCAR model results especially with solar zenith angles below 70^º.