Abstract
Climate models robustly project acceleration of the Brewer-Dobson
circulation (BDC) in response to climate change. However, the BDC trends
derived from comprehensive models do not fully match observations.
Additionally, the changing structure of the troposphere and stratosphere
has received increasing attention in recent years and to which extent
vertical shifts of the circulation are driving the acceleration is under
debate. In this study, we present a novel method that enables the
attribution of circulation changes to individual kinematic factors.
Using this method allows to study the advective BDC trends in
unprecedented detail and sheds new light into discrepancies between
different datasets (reanalyses and models) at the tropopause and in the
lower stratosphere. Our findings provide insights into the reliability
of model projections of BDC changes and offer new possibilities for
observational constraints.