Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) Observations of Polar Winter Conditions in 2009; Comparisons with Years 2002- 2008

摘要

This report summarizes results from eight years of observations of northern polar winters by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, with a specific focus on the year 2009. That winter, like all but one since the TIMED launch, featured an extraordinarily intense stratospheric sudden warming (SSW). We have documented its effects on stratospheric and mesospheric temperature, and on the OH layer in the upper mesosphere, and compared them with those in other years- particularly 2006, which had a very similar SSW. We show that mesospheric cooling accompanied each SSW, but with varying altitude ranges, durations, and overall effect. Cooling in the upper mesosphere, when it could be discerned, preceded both the SSW and the cooling at lower altitudes by a few days. Years 2004, 2006, and 2009 stood out with extraordinary disruptions of the mesospheric temperature structure, and very low bright OH layers, in the weeks after the SSWs. Year 2008 featured four separate weaker but remarkably consistent warmings. We also looked for, but could not confirm, signs of remote SSW influences in the equatorial region.