Current Work

Extratropical cyclone development:

I'm interested in extratropical cyclone development mechanisms. I have carried out work investigating the spatial and evolution characteristics of north Atlantic cyclones (Dacre and Gray (2008). Currently I am investigating the effect of latent heat release on extratropical cyclone development in collaboration with Sue Gray (Meteorology), Tim Hewson (Met Office/ECMWF) and Kevin Hodges (ESSC) and supervise a PDRA, Marc Stringer, who is working on this project. I will continue this work through supervision of a PhD student to begin in January 2010, funded under NERC's Storm Risk Mitigation research programme. <\/>

Pollution transport in numerical weather prediction models:

During my postdoc I investigated the transport of pollutants during high pressure events. In a case study simulated using the Met Office forecast model, I found that a region of enhanced convection and transport existed along the south coast of the UK associated with a sea breeze circulation (Dacre et al. (2007). I have continued to investigate the transport of pollution by coastal processes through supervision of a PhD student, Dan Peake. Dan's work focuses on coastal outflow, the horizontal ventilation of pollutants at the coast from the well mixed continental boundary layer into the stable layer existing above the marine boundary layer. A 4-week period has been simulated using the Met Office forecast model and comparision with observations will be made to determine the relative importance of coastal outflow on boundary layer ventilation. Related work in the area of pollution transport by weather forecast models is being carried out through supervision of another PhD student, Natalie Moore. Natalie is investigating the transport of pollution by boundary layer mixing. Natalie is using long-term measurements taken by a vertically pointing Doppler lidar to characterise boundary layer turbulence profiles and identify different cloud types over a site in southern England. Boundary layer types diagnosed by the Met Office forecast model will be evaluated using this unique observational dataset.

Pollution transport in dispersion models:

In the last few years I have been working closely with the dispersion group at the Met Office to evaluate the ability of weather forecast models to predict pollutant concentrations. I have performed simulations of pollutant transport for the European Tracer Experiment (ETEX) releases and compared pollution predictions made by the Met Office dispersion and weather forecast models. Predictions have also been evaluated using observations from the ETEX dataset (Dacre (2010)). A new evaluation method has been developed to enable quantitative comparison of the model and observed concentrations (Dacre (submitted)). Further work using the Met Office dispersion model has been carried out through supervision of 2 MSc student projects (Davis and Dacre (2009)) and one undergraduate project (Stock et al. (in prep)). Recently, I have performed simulations of the Icelandic volcano eruptions in collaboration with the Met Office. Comparison of these model predictions with observations has enabled estimates of the volcano source characteristics to be made (Dacre et al. (in prep)). I also supervise a PDRA, Alan Grant, who is investigating the dispersion of volcanic ash funded by an NCAS grant.

Previous Work

Slantwise circulations

This project involved high resolution idealised modelling experiments to simulate the formation and evolution of mesoscale slantwise circulations in a region of frontogenetic forcing. Using the idealised version of the Met. Office Unified Model the effect of frontogenetic forcing on the strength, horizontal extent and number of circulations was analysed.

Frontal Waves

During my PhD I compiled a dataset of extratropical cyclones by applying an automated feature tracking algorithm to a database of objectively identifiedq cyclonic features. The cyclones were then classified according to their development mechanisms and a new climatology of extratropical cyclones was produced. I also performed high resolution idealised modelling simulations of frontal wave development and found that their development was strongly dependent on the strength and time evolution of the deformation field acting on the front.