Publication Date:
2020-12-18
Description:
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 – 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 January 19, 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 airmasses arriving to 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 extra-tropics was also occasionally observed to produce elevated values of N2O mixing ratio. Starting from mid-February the temperature profile and the N2O mixing ratio returned to the pre-warming 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.
Description:
Published
Description:
D24315
Description:
1.7. Osservazioni di alta e media atmosfera
Description:
1.10. TTC - Telerilevamento
Description:
JCR Journal
Description:
open
Keywords:
sudden stratospheric warming
;
winter polar stratosphere
;
temperature
;
O3
;
N2O
;
CO
;
01. Atmosphere::01.01. Atmosphere::01.01.01. Composition and Structure
;
01. Atmosphere::01.01. Atmosphere::01.01.04. Processes and Dynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
