Strong Dynamical Modulation of the Cooling of the Polar Stratosphere Associated with the Antarctic Ozone Hole

• Published in: Journal of climate Vol. 26; no. 2; pp. 662 - 668
• Main Authors: Orr, Andrew, Bracegirdle, Thomas J., Hosking, J. Scott, Feng, Wuhu, Roscoe, Howard K., Haigh, Joanna D.
• Format: Journal Article
• Language: English
• Published: Boston, MA American Meteorological Society 01.01.2013
• Subjects: Antarctic ozone; Antarctic ozone hole; Antarctica; Atmospheric circulation; Atmospheric composition. Chemical and photochemical reactions; Atmospheric models; Climate change; Climate models; Computer simulation; Cooling; Datasets; Depletion; Earth, ocean, space; Exact sciences and technology; External geophysics; Fluid flow; Heating; Modeling; Modulation; Ozone; Ozone depletion; Ozone hole; Physics of the high neutral atmosphere; Radiation; Radiative cooling; Simulation; Simulations; Southern Hemisphere; Stratosphere; Stratospheric vortices; Temperature; Trends; Tropopause; Vortices; Weather; polar regions; Antarctica; Southern Hemisphere; Ozone holes; Polar vortex; Southern Hemisphere; General circulation models; Antarctic stratospheric vortex; cooling; Brewer-Dobson circulation; Climate models; Polar region; atmospheric circulation; stratosphere
• ISSN: 0894-8755; 1520-0442
• DOI: 10.1175/JCLI-D-12-00480.1

A model simulation forced by prescribed ozone depletion shows strong dynamical modulation of the springtime cooling of the polar stratosphere associated with the Antarctic ozone hole. The authors find that in late spring the anomalous radiative cooling in response to ozone depletion is almost canceled above ∼100 hPa by an increase in dynamical heating. Between ∼300 and ∼100 hPa, however, it is enhanced by a reduction in dynamical heating, resulting in the descent of the cold anomaly down to the tropopause. In early summer increased dynamical heating dominates as the radiative cooling diminishes so that the cold anomaly associated with the delayed breakup of the stratospheric vortex is reduced. The anomalous dynamical heating is driven by changes in the Brewer–Dobson circulation arising primarily from the dissipation of resolved-scale waves. The model changes are broadly consistent with trends from reanalysis and offline diagnoses of heating rates using a radiation scheme. These results help one to understand dynamically induced change in the evolution and timing of the stratospheric vortex in recent decades and will help to enable improved simulation of the Southern Hemisphere climate.