Upward and downward irradiation measurements on board of geophysica aircraft during APE-THESEO and APE-GAIA field campaigns

This work presents a method of measurement, instrumentation and preliminary results of upwelling and downwelling irradiation measurements obtained during APE-THESEO (Mache, Seychelles, February-March, 1999) and APE-GAIA (September-October, 1999, Ushuaia, Argentina) field campaigns.
The measurements have been carried out on board of M55-Geophysica aircraft, mainly in the lower stratosphere near to 20km altitude. An UV-Vis spectroradiometer named GASCOD-A4pi has been employed during above mentioned campaigns in two operational modes: Differential Optical Absorption Spectroscopy (DOAS) for retrieving of NO2, O-3, BrO, and etc. stratospheric minor gases content and in a SpectroRadiometric (SR) mode for solar irradiation measurements. The second mode permit to calculate the photolysis rate coefficients of stratospheric minor gases. The laboratory tests and some preliminary results from both campaigns are presented and discussed.