Monthly averaged BrO column abundances

Time series of monthly averaged BrO column abundances measured over Harestua (60°N, 11°E) by SCIAMACHY limb (right) and ground-based UV-visible (left) instruments. Thick lines indicate trend analysis results. A decline of -0.6+/-0.3% per year is estimated from SCIAMACHY limb observations over the 2002-2008 period, which is in good agreement with ground-based UV-visible measurements (-0.7+/-0.3%/year).