Andrew Charlton-Perez: Research Interests

Dynamical Links between the Stratosphere and Troposphere

A large part of what I work on is focussed on understanding the question 'Does the Troposphere care about the Stratosphere?' In recent years there has been renewed interest in understanding how changes to the stratospheric flow influence tropospheric variability on timescales from 10 days through months to many years. My research in this area tries to:

• Understand how the Stratosphere influences Tropospheric behaviour, particularly in terms of its influence on Tropospheric weather systems or baroclinic waves.
• Quantify the gains in predictability which may come about due to proper representation of Stratospheric processes.
• Understand what role changing Stratospheric climate has in polar climate change.

Stratospheric Dynamics and Stratospheric Sudden Warmings

One of the most fascinating and exciting parts of the Atmospheric circulation is the Stratospheric Sudden Warming (SSW). Over the course of a few days, large changes to the mean circulation in the Stratosphere can occur as the wintertime polar vortex is disturbed and in some cases destroyed. Understanding this process, and the reasons why some years in the Stratosphere are disturbed and some are not is a key challenge for Stratospheric research. My research in this area tries to:

• Develop comprehensive climatologies of SSWs using novel analysis techniques.
• Develop stringent tests of the reproduction of the SSW climatology for general circulation models and coupled chemistry-climate models.
• Investigate the particular dynamical evolution and causes of the Southern Hemisphere Sudden Warming in 2002 and its role in the larger Southern Hemisphere stratospheric climate.

Idealised Modelling of the Earth System

While much current Atmospheric science uses complex GCMs to analyse and predict weather and climate, there is still a great deal which can be learnt from simpliified and inexpensive idealised models. In particular I use the Reading Intermediate General Circulation Model (IGCM) for experiments to investigate Stratospheric dynamical questions and Stratosphere-Troposphere links.

New Methods for Characterising Atmospheric Variability

Increasingly a wealth of atmospheric data is available through archives of re-analysis data and of GCM output. A further research goal is to develop novel analysis techniques for analysing this data. These techniques should be simple enough that they can be reproduced by other scientists working on the same problem but complex enough to fully describe the fundamental dynamical processes present in the dataset. Currently this work is focussed on understanding variability in the Stratospheric polar vortex, but I am keen to expand into other areas of atmospheric science.