Non-Equilibrium Convection

Either implicitly or explicitly, many existing ideas about atmospheric convection are based on an equilibrium assumption. The convection is assumed to maintain a state very close to an equilibrium that balances the forcing mechanism. All of the convective parameterization schemes used in weather forecast and climate models make this assumption in some form. However, there are many situations for which the assumption is not valid, and where the departures from equilibrium may be a significant feature of the flow. This project uses a cloud-resolving model to perform numerical simulations of the response of the atmosphere to various changes in the forcing. The aim is to determine the behaviour and evolution of convective cloud fields under non-equilibrium conditions, leading to an understanding of the timescales and mechanisms of transitions between different equilibrium states.

Some links for this work:

Publications:

1. Paper on CRM simulations with rapidly-varying forcings
2. Paper on a simple model for convective memory (editor's highlight in JGR)
3. PhD thesis by Laura Davies on Self Organization of Convection as a Mechanism for Memory

Talks:

1. An invited talk on the limitations of quasi-equilibrium given at a Workshop on Concepts for Convective Parmeterisations in Large-Scale Models, 12-14 February, MPI Hamburg, Germany. The workshop report can be found here.
2. Talk on memory aspects of convection given (by L. Davies) as an departmental seminar at Reading.
3. Talk on quasi-equilibrium given (by L. Davies) at the RMetS conference 2007 in Edinburgh.
4. Talk on equilibrium assumptions given (by L. Davies) at the 15th Apline Summer School (Atmosphere-Ocean Convection in Climate Dynamics) in Valle d'Aosta, Italy.

Posters:

1. Poster presented (by L. Davies) at the EGU Assembly 2007 in Vienna.
2. Poster and slides introducing it presented at the EGU Assembly 2006 in Vienna.
3. Poster presented (by L. Davies) at the RMetS conference 2005 in Exeter.