Evolution of temperature, O₃, CO, and N₂O profiles during the exceptional 2009 Arctic major stratospheric warming as observed by lidar and millimeter‐wave spectroscopy at Thule (76.5°N, 68.8°W), Greenland

Abstract

The 2009 Arctic sudden stratospheric warming (SSW) was the most intense event of this kind ever observed. Unique ground‐based measurements of middle atmospheric profiles for temperature, O3, CO, and N2O obtained at Thule (76.5°N, 68.8°W), Greenland, in the period January to early March are used to show the evolution of the 2009 SSW in the region of its maximum intensity. The first sign of the SSW was detected at θ ∼ 2000 K on 19 January, when a rapid decrease in CO mixing ratio took place. The first evidence of a temperature increase was observed at the same level on 22 January, the earliest date on which lidar measurements reached above ∼50 km. The warming propagated from the upper to the lower stratosphere in 7 days and the record maximum temperature of 289 K was observed between 1300 and 1500 K potential temperature on 22 January. A strong vortex splitting was associated with the SSW. Stratospheric backward trajectories indicate that air masses arriving at Thule during the warming peak underwent a rapid compression and an intense adiabatic warming of up to 50 K. The rapid advection of air from the extratropics was also occasionally observed to produce elevated values of N2O mixing ratio. Starting in mid‐February the temperature profile and the N2O mixing ratio returned to the prewarming values in the mid and upper stratosphere, indicating the reformation of the vortex at these levels. In late winter, vertical descent from starting altitudes of ∼60 km is estimated from CO profiles to be 0.25 ± 0.05 km/day.

Strato-mesospheric carbon monoxide profiles above Kiruna, Sweden (67.8 ° N, 20.4 ° E), since 2008

“…The smoothing error can be large for ground-based profiling instruments due the small altitude spacing between retrieval grid points, chosen here for numerical stability in the inversion (Eriksson, 1999), compared to the actual vertical resolution of the retrieved profiles (see Fig. 1c and d).…”

“…Damiani et al, 2014;Lee et al, 2011;Manney et al, 2009;McLandress at al., 2013), ground-based CO profile data sets for the poles are few and far between. The ground-based millimetre-wave spectrometer (GBMS) installed in Thule Air Base, Greenland (76.5 • N, 68.7 • W), was used to study the composition of the Arctic winter atmosphere in 2001/02 (Muscari et al, 2007) and the sudden stratospheric warming (SSW) of 2009 (Di Biagio, et al, 2010). The Onsala Space Observatory instrument (57 • N, 12 • E) measured CO in (Forkman et al, 2012 and from 2014.…”

Observation of strato-mesospheric CO above Kiruna with ground-based microwave radiometry – retrieval and satellite comparison

“…Since then, a number of ground-based microwave radiometers have been developed and used for studies covering various time periods in several locations, demonstrating the potential of analyses of CO datasets (e.g. Bevilacqua et al, 1985;Aellig et al, 1995;Forkman et al, 2003;Di Biagio et al, 2010).…”

Ground-based stratospheric O<sub>3</sub> and HNO<sub>3</sub> measurements at Thule, Greenland: an intercomparison with Aura MLS observations

“…Since then, four winter campaigns have been carried out during the period JanuaryMarch 2009-2012(Di Biagio et al, 2010Muscari et al, 2012), and regular winter campaigns are planned for the future.…”