Predictability of stratospheric warming in an idealized model

It is well known that the stratospheric sudden warming events are closely connected to the tropospheric planetary waves, however, it is still not clear to what extent the troposphere/stratosphere control the stratospheric sudden and final warming. In an idealized atmosphere model, a series of perturbation experiments for the sudden and final warmings are carried out to test the roles of the troposphere and the stratosphere in determining the predictability of stratospheric warmings. For a late final warming, almost all of the predictability comes from the troposphere. For the rest of the final warmings and for the sudden warmings, however, the troposphere determines the predictability until very close to the time of warming onset. This finding, consistent with the conventional view of the warming, reflects that center role of the troposphere in determining the stratospheric warmings and help better understand the stratospheric predictability.