Stratospheric NO2 observation at mid and high latitude performed with ground-based spectrometers

UV-Visible ground-based spectrometers were developed at the ISAO Institute and they are used for application of Differential Optical Absorption Spectroscopy (DOAS) methodology to detect stratospheric trace gases involved in the ozone cycle such as NO2, OClO, and BrO. Observations of the light scattered from the zenith-sky were performed with the instrumentation above mentioned, in various stations situated in both the hemispheres (Are Ostersund - 63.11 N, 14.39 E, Sweden; Mt Cimone - 44.11 N, 10.42 E, Italy; Stara Zagora - 42.25 N, 25.38 E, Bulgaria; Terra Nova Bay - 74.68 S, 164.11 E, Antarctica). Some problematics connected to data validation and results analysis are introduced. Considerations about the temperature dependency of the cross-section used for the determination of the trace gases slant column are carried out. Results for nitrogen dioxide abundances at different seasons and various Solar Zenith Angle (SZA) in theirs seasonal and diurnal variation are presented and discussed. Finally, the behaviour of the sunrise nitrogen dioxide abundance (AM sc) over the sunset slant column (PM sc) is showed and examined.