Shallow clouds

Building new climate models that penetrate the turbulence frontier:

This line of research addresses an existential question in climate change prediction – will future regional reorganizations of low cloud amount and act to brighten the planet (buffering global warming) or dim it (amplifying global warming and its associated human impacts)?

Low clouds such as marine stratocumuli are especially important to global climate sensitivity but are extremely challenging to simulate globally, even in superparameterized atmospheric models, since the turbulent eddies that control them form on length scales smaller than 200 m operating in the vicinity of sharp vertical temperature gradients that require ~ 10-20m vertical resolution to resolve. Since 2014 I have been building a new type of multi-scale climate model designed to avoid traditional approximations of these cloud systems to confront uncertainties in their climate interactions. In Parishani et al. (2018) we reported a first scientific result – more faithfully resolving the low-cloud-forming eddies has remarkably little effect on the mean cloud response to +4K sea surface warming. This may imply there are deeper constraints on the cloud feedback to warming than have been previously appreciated. I am actively continuing this line of work together with UCI postdoc Liran Peng to probe issues of aerosol-cloud interaction that are distinct from surface warming but equally important to climate uncertainty. This work is deeply collaborative with Chris Bretherton and Peter Blossey at the University of Washington.


164 Rowland Hall
University of California, Irvine
Irvine, CA 92697-4675