A new method of derivation of photolysis rate from a moderate bandwidth filter radiometer

A method to derive the photodissociation rate of O3 and NO 2 from irradiance measurements with a moderate bandwidth filter radiometer was discussed. The global irradiance measurements from GUV in Manchester, UK, were compared with independently measured photolysis rate determined from the measured actinic flux on a single clear sky day. On the reference day, a linear regression of GUV global irradiance to simultaneous photolysis rate measurements was performed to generate scale factors for each optical channel. The agreement between the measured and the calculated photolysis rate from the empirical equation at different solar zenith angles agreed within 20% under all conditions tested.