Cloud Lifecycles and Tracking in Numerical Models

My interests in this area cover two aspects.

• The DYMECS project is using the Chilbolton radar to gather statistics on hundreds of convective storms, tracking their evolution with time. We will make a statistical comparison of the observed and modelled evolution of storm size, rain rate, ice content, turbulence and updrafts. The relevant model is the UKV, the variable-resolution, convective-permitting forecasting model of the Met Office. Its resolution ranges from 4km at the boundaries to 1.5km in the interior of the model domain. Although such a model is convection permitting one would ceratinly not expect it to be able to resolve the convection well. But the key issue is to assess which aspects of the convective storms can be adequately represented and which are less reliable. We will then assess the sensitivity of modelled storm properties to microphysics (e.g. graupel and double-moment ice), sub-grid mixing and resolution, going to as fine as 200m.
• Traditional methods of cloud tracking assume that one starts from two snapshots of the cloud field and attempts to relate objects in the second image to objects in the first. The methods used are typically more and more complicated and more and more uncertain as the time between snapshots increases. However, the starting point for this work is the simple point that in a model one can essentially make the snapshots arbitrarily close together. The methods needed then become very much simpler and much of their ambiguity or arbitrariness simply vanishes. I have written code for such a novel method of tracking on-the-fly for cloud-resolving model (CRM) simulations. The method tracking the complete evolution of cumulus clouds in the model.

Some links for this work:

Papers:

1. A paper on estimating convective vertical velocities
2. A paper giving an overview of key DYMECS results
3. A paper on three dimensional cloud structure
4. A paper on the effects of mixing length on explicit convection simulations Kirsty Hanley received the 2018 LF Richardson prize of the Royal Met Soc in recognition of leading this work.
5. A paper on the method and the effects of cloud splitting/merging

Talks:

1. A summary of the role of turbulent mixing presented at the 2016 RMetS NCAS conference.
2. A summary of DYMECS results presented (by Thorwald Stein) the 2016 EGU assembly.
3. A summary of DYMECS results presented (by John Nicol) as a Met Office seminar.
4. A talk on the statistics of storms in the UKV model presented (by Thorwald Stein) at the Cascade downstream workshop.
5. A talk on the statistics of storms in the UKV model presented (by Humphrey Lean) at the WWOSC conference, Montreal, August 2014..
6. A talk on DYMECS results presented (by Kirsty Hanley) at the AMS annual meeting, Atlanta, February 2014..
7. A talk on tracking the 3D structure of convective storms presented (by Thorwald Stein) at the 13th EMS Annual Meeting and 11th European Conference on Applications of Meteorology.
8. A seminar on storm morphology in high-resolution models presented at Imperial College.
9. A talk on mixing length sensitivities of modelled convective storms presented (by Kirsty Hanley) at the 2013 EGU assembly.
10. A talk on mixing length sensitivities of modelled convective storms presented (by Kirsty Hanley) at the JWCRP workshop on Understanding and Represnting Convection Across Scales, at Dartington.
11. A talk on tracking the 3D structure of convective storms presented (by Thorwald Stein) at the 7th European Conference on Severe Storms.
12. A talk on radar tracking of convective storms presented (by Robin Hogan) at an RMetS national meeting, at London.
13. A talk on tracking the 3D structure of convective storms presented (by Thorwald Stein) at the 26th AMS Conference on Severe Local Storms.
14. A DYMECS overview presented (by Thorwald Stein) at the NCAS Weather Rainfall Forum.
15. A DYMECS overview presented (by Robin Hogan) at a science meeting of the COPE project
16. A DYMECS archive of various project-related presentations
17. A departmental seminar on convective cloud lifecycles
18. A talk presented at the RMetS conference 2007 in Edinburgh.

Posters:

1. Poster on evaluation of convective storms in NWP models presented (by Thorwald Stein) at the 2017 CFMIP conference in Tokyo.
2. Poster on the mixing length controls on convective storms presented (by Robin Hogan) at the 2014 AMS Clouds conference in Boston.
3. Poster on the 3D structure of tracked storms presented (by Thorwald Stein) at the 2013 EGU conference in Vienna.
4. Extended abstract for poster at the 4th European Conference on Severe Storms, Trieste, Italy, 10-14 September 2007.

Data:

1. An animation of the 25 August 2012 case as aimulated with a 200m gridlength model
2. An animation of the 25 August 2012 case as aimulated with a 1.5km gridlength model
3. An archive of DYMECS case studies, with quicklooks of observational and model data
4. An archive of DYMECS modelling results

Others:

1. Article on DYMECS project in Met Office research news
2. Description of DYMECS project in the MOAP newsletter
3. An item on the Weather and Climate Discussion blog pages: April showers
4. Description of DYMECS (by Robin Hogan) on a NERC podcast