PI	Stelios Kazadzis
Participant	National Observatory of Athens

NOA Atmospheric remote sensing station is equipped with an Ultraviolet Multi-filter Radiometer (UVMFR) instrument for radiation
measurements in the UV spectral region. UVMFR measures both total and diffuse irradiance at 7 specified wavelengths (300, 305.5, 311.4, 317.6, 325.4, 332.4, and 368nm) with a 2nm nominal full width at half maximum (FWHM) bandwidth. Measurements of total and diffuse irradiance are recorded every 10s, and stored as 1min averages along with a computation of the direct irradiance. Using the Langley calibration method the instrument provides aerosol optical thickness in all the above wavelengths and using the differential absorption modified algorithm total column ozone. The combination of CIMEL and UVMFR instrument with the aid of radiative transfer models can provide information about optical and microphysical aerosol properties in the UV region.