Long-term trends of mesospheric temperatures over Kiruna (68N, 21E) during 2003-2014

Abstract

We have analyzed mesospheric temperatures from OH airglow measurements with a Fourier Transform Spectrometer (FTS) in the period of 2003？2014 at Kiruna (68°N, 21°E). We have derived the seasonal variation, solar response and long-term variation of mesospheric temperatures over Kiruna. In addition, FTS temperatures show signals of sudden stratospheric warming (SSW). After removing the estimated solar response of 5.0 ± 1.5 K/100SFU, we find the long-term trend of ？2.6 ± 1.5 K/decade, indicating a weak cooling trend at the high latitude. We discuss our results by comparing with those of Microwave Limb Sounder (MLS) instrument on board Aura satellite.