Department of Earth and Space Sciences, Chalmers University of Technology, Gothenburg, Sweden
Abstract. A Sudden Stratospheric Warming (SSW) affects the chemistry and dynamics of the middle atmosphere. The major warmings occur roughly every second year in the Northern Hemispheric (NH) winter, but has only been observed once in the Southern Hemisphere (SH), during the Antarctic winter of 2002. Using the National Center for Atmospheric Research's (NCAR) Whole Atmosphere Community Climate Model with specified dynamics (WACCM-SD), this study investigates the effects of this rare warming event on the ozone layer located around the SH mesopause. This secondary ozone layer changes with respect to hydrogen, oxygen, temperature, and the altered SH polar circulation during the major SSW. The 2002 SH winter was characterized by three zonal-mean zonal wind reductions in the upper stratosphere before a fourth wind reversal reaches the lower stratosphere, marking the onset of the major SSW. At the time of these four wind reversals, a corresponding episodic increase can be seen in the modeled nighttime ozone concentration in the secondary ozone layer. Observations by the Global Ozone Monitoring by Occultation of Stars (GOMOS, an instrument on board the satellite Envisat) demonstrate similar ozone enhancement as in the model. This ozone increase is attributable largely to enhanced upwelling and the associated cooling of the altitude region in conjunction with the wind reversal. Unlike its NH counterpart, the secondary ozone layer during the SH major SSW appeared to be impacted more by the effects of atomic oxygen than hydrogen.
This preprint has been withdrawn.
How to cite. Smith-Johnsen, C., Orsolini, Y., Stordal, F., Limpasuvan, V., and Pérot, K.: Nighttime Mesospheric Ozone During the 2002 Southern Hemispheric Major Stratospheric Warming, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2016-758, 2016.
Received: 22 Aug 2016 – Discussion started: 29 Sep 2016
Mesospheric ozone enhancements during sudden stratospheric warmings in the northern hemisphere have been reported in the literature. In the southern hemisphere, only one warming event has occurred, and this paper is the first to explain the mesospheric ozone enhancement during this event in 2002, using both a whole atmosphere chemistry climate model and satellite observations from GOMOS.
Mesospheric ozone enhancements during sudden stratospheric warmings in the northern hemisphere...