Dr Michael Whitall

Areas of Expertise

•     Atmospheric Convection

•     Large Eddy Simulation

•     Feature-Tracking

Current Activities

Michael works as part of the Moist Atmospheric Convection, to develop improvements to the Atmospheric Processes and Parametrizations which represent convection in weather and climate models.  His work has a particular focus on the initiation of convection, looking at the processes which "trigger" the onset of convective updrafts.

In order to guide improvements to parameterisations, advances in our understanding of the underlying physics are required.  To this end, many measurements of the properties of convective clouds have been made by international field studies, such BOMEX, RICO, TOGA-COARE and TWP-ICE.  But it is challenging to get enough detail from these data to study the small-scale processes often responsible for initiating convection.  Further insight can be gained by simulating convection using idealised very high-resolution models (such as the Met Office Large Eddy Model).

Michael has recently focused on analysing LEM simulations based on the aforementioned field studies, with the aim of assessing and improving the Unified Model's convective triggering conditions, which determine when and where the convection parameterisation is activated in lower-resolution simulations.  This work involves developing analysis tools to track the simulated convective updrafts as they evolve in the LEM, tracing them back to their origins to extract the conditions which induced them to form.  The cloud-tracking scheme made for this purpose also has applications in other research areas; for example, to study the relationship between rainfall and cloud droplet number concentration in shallow cumulus.

Current work also involves using the UM in its Single-Column Model (SCM) configuration; this is a framework for testing parameterisations by simulating a single vertical profile of temperature, moisture and clouds, with prescribed large-scale dynamics.  Michael is performing SCM simulations for the GASS WTG intercomparison project, and will take on responsibility for maintaining the SCM code for other users in the future.

Career Background

Michael joined the Met Office in 2013, when he took up his current role in the Moist Atmospheric Convection within Atmospheric Processes and Parametrizations.  Previously, Michael completed a PhD in Meteorology at the University of Reading, where he also studied Physics and Meteorology as an undergraduate.  His PhD thesis investigated the sensitivity of the atmosphere to fast variability associated with convection and other parameterised processes.