Near UV atmospheric absorption measurements of column abundances during Airborne Arctic Stratospheric Expedition, January – February 1989: 1. Technique and NO2 observations

Spectroscopic measurements of column abundances of NO2 were carried out from the NASA DC‐8 airplane during the Airborne Arctic Stratospheric Expedition in January and February 1989. Stratospheric airmasses inside and close to the polar vortex were found to be highly depleted of NO2 with lowest vertical column abundances of NO2 below 2 × 1014 cm−2 compared to abundances of 3 – 5 − 1015 cm−2 south of 50° N in winter (WMO, 1985).