Column abundances of BrO were measured during the Airborne Arctic Stratospheric Expedition from January 6 to February 9, 1989 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¿1013 cm-2 and 13¿1013 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. ¿ American Geophysical Union 1990