A193-01
Investigating physical constraints on climate feedbacks using a perturbed parameter ensemble

Tuesday, 15 December 2020: 07:00
Virtual
Yoko Tsushima1, Mark Ringer1, Gill Martin2, John W Rostron3 and David Sexton3, (1)Met Office Hadley center for Climate Change, Exeter, United Kingdom, (2)Met Office, Hadley Centre for Climate Change, Exeter, United Kingdom, (3)Met Office, Hadley Centre for Climate Science and Services, Exeter, United Kingdom
Abstract:
A large parameter-perturbed ensemble (PPE) of the Met Office climate model is used to explore the relationship between radiative feedbacks and the present-day simulation of the associated physical processes.
The influence of convection is largely confined to the tropical deep convective regions in the present day but extends to mid-latitudes under warming. Because of this, contributing processes to the spread in the present-day and the response are different in the extra-tropics, making it much more difficult to establish links between the present-day and the feedback within the region. This suggests that identifying a constraint on convective processes in the tropics for the present-day simulations could constrain both the tropical feedbacks and feedbacks in the extra-tropics. Understanding and improving the detailed processes controlling feedbacks is ultimately only possible in individual models. Different process-based constraints might be inferred for different models. The approach described here could usefully extended to other single model ensembles and the collective understandings could be valuable for improving model process and feedbacks more generally.