Dr Carol Halliwell
Carol works on the representation of subgrid-scale mixing in convective-scale versions of the Unified Model.
Areas of expertise
Convective scale modelling
- Unified Model code development
Carol's work is focused on the representation of subgrid-scale mixing in convective-scale versions of the Unified Model. The aim of this work is to determine the best configuration for future operational models. Her work explores the suitability of the current boundary layer, convection and subgrid turbulence schemes at these high resolutions. Carol's current work includes assessment of potential enhancements to the Smagorinsky-based subgrid turbulence scheme including the introduction and evaluation of a stochastic backscatter scheme.
Much of Carol's research is carried out using an idealised version of the Unified Model, a tool for which she provides guidance and support to other users both within and outside the Met Office. The Idealised Unified Model enables users to focus on particular aspects of the model in controlled situations. Carol's work currently involves assessing different options for representing subgrid-scale mixing by running idealised simulations of convective development over land. The idealised studies, run with a grid length of order 1 km down to 100m, complement research using real forecasting case studies carried out at MetOffice@Reading and the wider Met Office.
Carol has worked at MetOffice@Reading (formerly JCMM) since joining the Met Office in 1999. Prior to this, Carol completed a PhD in the study of atmospheric convection at the University of Leeds, where she also received an undergraduate degree in Mathematics.
Since joining the Met Office, Carol has been involved in the development and maintenance of an idealised version of the Unified Model. This is the main tool which Carol has used in her investigations into the representation of convection and turbulence in high-resolution versions of the Unified Model. Carol has also contributed to GCSS intercomparisons.
Carol has also developed code within the Unified Model. This includes introducing bi-periodic lateral boundary conditions into the Idealised UM and implementing a subgrid turbulence scheme into the Unified Model, based on the Smagorinsky-Lilly formulation and similar to that used in the Met Office Large Eddy Model.