Measured UV spectra compared with discrete ordinate method simulations

摘要: A comprehensive radiative transfer model is used to calculate surface spectral ultraviolet irradiance under cloud-free conditions. The results are compared with measurements made at Lauder, New Zealand (45 deg S, 170 E) before and after the eruption of Mount Pinatubo including a snow-covered surface. There reasonable agreement between measured calculated diffuse, direct, global irradiances over range 300 450 nm. Discrepancies may be due calibration errors in UV measurements, or extra terrestrial input model. Ratios diffuse/direct independent such uncertainties therefore provide sensitive test If appropriate ozonesonde data, albedo, aerosol optical properties used, ratios satisfactory wide observing For cases which atmospheric best known better than 8% UV-B range, for wavelengths 320 nm deviation smaller. comparison suggests that radiation exposure can computed confidence clear sky conditions if molecular density profiles, available.more » investigate impact changes solar zenith angle, ozone abundance, loading on reaching Earth. diffuse direct depend critically extinction. Ozone have pronounced effects UVB but only minor effect these ratios.« less