The generic nature of the tropospheric response to sudden stratospheric warmings

Please see our new paper on the tropospheric response to extreme events in the stratosphere, just submitted to the Journal of Climate. Update: this paper was accepted for publication in January 2020!

This study, lead by Ian White, looks at the long term tropospheric response to Sudden Stratospheric Warming events, abrupt disruptions of the winter stratosphere. We compare naturally occuring events to events “triggered” by a warming perturbation to the stratosphere. It’s as if we detonated a thermal explosion in the polar stratospheric vortex, one that deposited a great deal of heat (but otherwise caused no harm!) We find that after the first couple weeks, the tropospheric response to triggered warming events is essentially the same as that to naturally occuring event.

This allows us to unambiguously attribute the long range tropospheric response to changes in the stratosphere. In a naturally occuring event, the troposphere “blows” up the stratosphere by sending up a lot of momentum. It previously was unclear whether this initial transfer of momentum from the troposphere to the stratosphere played a role in the tropospheric response.

Ian is a postdoc in Chaim Garfinkel’s group at Hebrew University, Jerusalem. We used the MiMA model, developed by co-author Martin Jucker at the University of New South Wales, and worked with Peter Hitchcock at Cornell and Jian Rao at Hebrew University.