Brief communication &amp;quot;Stratospheric winds, transport barriers and the 2011 Arctic ozone hole&amp;quot;

M J Olascoaga,M G Brown,F J Beron-Vera,H Koçak

doi:10.5194/npg-19-687-2012

Abstract

Abstract. The Arctic stratosphere throughout the late winter and early spring of 2011 was characterized by an unusually severe ozone loss, resulting in what has been described as an ozone hole. The 2011 ozone loss was made possible by unusually cold temperatures throughout the Arctic stratosphere. Here we consider the issue of what constitutes suitable environmental conditions for the formation and maintenance of a polar ozone hole. Our discussion focuses on the importance of the stratospheric wind field and, in particular, the importance of a high latitude zonal jet, which serves as a meridional transport barrier both prior to ozone hole formation and during the ozone hole maintenance phase. It is argued that stratospheric conditions in the boreal winter/spring of 2011 were highly unusual inasmuch as in that year Antarctic-like Lagrangian dynamics led to the formation of a boreal ozone hole.

Highlights

The highly unusual Arctic ozone loss in early 2011 has been well documented by Manney et al (2011), who described that event as an ozone hole, mainly because its associated chemistry was similar to that of annually recurring austral events
We show that the required confinement during both the stratospheric cooling phase and the ozone hole maintenance phase is linked to the presence of a stratospheric zonal jet which acts as a meridional transport barrier
We show that a zonal jet of this type is linked to the 2011 Arctic ozone loss, and that the associated Lagrangian dynamics are similar to those associated with annually recurring Antarctic ozone holes

Summary

Introduction

The highly unusual Arctic ozone loss in early 2011 has been well documented by Manney et al (2011), who described that event as an ozone hole, mainly because its associated chemistry was similar to that of annually recurring austral events. Maintenance of an already-formed ozone hole requires confinement of the ozone-depleted polar air to prevent that air from mixing with ozone-rich midlatitude air. We show that the required confinement during both the stratospheric cooling phase and the ozone hole maintenance phase is linked to the presence of a stratospheric zonal jet which acts as a meridional transport barrier. We show that a zonal jet of this type is linked to the 2011 Arctic ozone loss, and that the associated Lagrangian dynamics are similar to those associated with annually recurring Antarctic ozone holes

Methods

Results

Conclusion