Turbulent Processes Programme

Parachute is a five-year programme joint between the Met Office and several UK universities, and aims to improve the representation of turbulent processes in weather prediction models run at horizontal length scales of 10m-10km.

More specifically, the project “Putting the morph into CoMorph: Adapting convection parametrisation for the hard grey zone“ will help to develop the new CoMorph convection parameterization scheme. CoMorph has been developed over the last 5 years and is intended for future operational use by the Met Office. It has been extensively tested in large scale and idealized models. Developments are now required so that it will be able to operate successfully in the context of km-scale ensemble-based numerical weather prediction. Major science challenges in doing so will be the estimation of essential length scales in moist convective flows, the inclusion of physically-based scale-aware stochasticity and the asymptotic matching of mass-flux and turbulence-based approaches.

The project "A novel turbulence closure for High-Fidelity numerical weather prediction" will develop a new parameterization of atmospheric turbulence for scales in the turbulence grey zone. The parametrization aims to combine dynamic approaches to the estimation of turbulent length-scales in spatially filtered equations with higher-order closure methods. It will represent contributions to turbulent fluxes from different fundamental mechanisms, and an important outcome will be a scientific understanding of the role and importance of these different mechanisms. The scheme will be tested and evaluated using high-resolution idealised simulations and also real case studies, in particular cases from the WesCon field campaign that will provide data from multiple radars, aircraft, drones etc.

Other projects in the programme focus on evaluation of turbulence and boundary layer schemes in the grey zone, turbulence-microphysics coupling, predictability and surface heterogeneity. The programme is tightly connected to the WesCon field campaign of summer 2023.

Some links for this work:

Talks

1. An overview of moist convection and its parameterization presented at an NCAS summer school on climate modelling.

Field Campaign

1. Main campaign site and data links.
3. Live aircraft data.
4. An overview of the campaign.

Others:

1. Blog entry from a PhD student working on the campaign.
2. An RMS meeting about the campaign.
3. ITV news report based on a flight during the field campaign. Alternative link.
4. A Met Office article.
5. BBC Inside Science programme including a section on the field campaign.
6. Press release of programme launch from Reading.
7. Press release of programme launch from the Met Office.
8. Press release of programme launch from NCAS.
9. Press release of programme launch from FAAM.
10. Press release of programme launch from UKRI.
11. Introduction to field campaign on Met Office site.