Near UV atmospheric absorption measurements of column abundances during Airborne Arctic Stratospheric Expedition, January – February 1989: 3. BrO observations

Column abundances of BrO were measured during the Airborne Arctic Stratospheric Expedition from January 6 to February 9, 1989 by near UV absorption spectroscopy. BrO was detected during eight flights by scattered sunlight observations during twilight and direct moon light observations during the night. The daytime vertical column abundances of BrO varied between 2 × 10 13 cm −2 and 13 × 10 13 cm −2 and are consistent with observed OClO column abundances and chemical model calculations. The nighttime presence of BrO suggests different vertical profiles of BrO and ClO.