OH temperature re-analysis forced by recent variance increases

Upper mesosphere temperatures have been derived from hydroxyl near-infrared emissions at Wuppertal (51°N, 7°E) for many years. Recently a strong increase of temperature fluctuations was observed which forced a change of our data evaluation algorithm. Resulting re-analysis temperatures and derived parameters are presented in comparison to the earlier data. Changes are mostly seen in the years since 2001/2002. The re-analysis data show a strong positive trend of short-period fluctuations. There is a trend break at around 2001/2002. The annual amplitudes of the seasonal temperature variations are also measured and show a negative trend recently. Also this trend break occurs at about the same time. It needs to be determined yet whether the two trends are physically related, and what their origin might be.