Next Generation Weather and Climate Prediction: Atmospheric Model Dynamical Core
Lead Research Organisation:
Imperial College London
Department Name: Aeronautics
Abstract
The next generation of weather and climate models used by the UK Met Office (as well as the community of weather and climate researchers in the UK) will be run on supercomputers with an enormous number of processors operating in parallel. Running a weather model on such a supercomputer has the simple requirement that doubling the number of parallel processors will halve the time required to make a forecast: this is called 'parallel scaling'. It is a great challenge of scientific computing to get a computer model to scale well on massive supercomputers; unfortunately some algorithms used in models make the forecast very accurate, but do not scale well. The aim of the NGWCP project is to identify new algorithms that can scale well on supercomputers without sacrificing forecast skill (the ability of a model to correctly forecast the weather). In this proposal, we choose to concentrate on two aspects, the horizontal grid, and the transport algorithms. In the current Met Office model, a latitude-longitude grid is used in the horizontal. This type of grid has the problem that all the lines of latitude converge on the poles, so they get closer and closer together. It turns out that this is very bad for parallel scaling. In this proposal, we suggest three new types of grids that keep grid lines the same distance apart all over the globe, keeping various favourable properties of the latitude-longitude grid. Transport algorithms in the model are responsible for modelling the movement of quantities (such as temperature or moisture) with the wind. In the Met Office Model, this is done by tracing back the paths of fluid parcels around the globe. It turns out that this method is also bad for parallel scaling. In this proposal, we will investigate some recently developed alternatives that do not require these path calculations. It is essential that these algorithms reflect physical principles at work in the real atmosphere, such as the Law of Conservation of Mass.
People |
ORCID iD |
Colin Cotter (Principal Investigator) |
Publications
Bendall T
(2019)
The 'recovered space' advection scheme for lowest-order compatible finite element methods
in Journal of Computational Physics
Cotter C
(2013)
A variational formulation of vertical slice models
in Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
Cotter C
(2014)
Variational formulations of sound-proof models Variational Sound-Proof Models
in Quarterly Journal of the Royal Meteorological Society
Cotter C
(2012)
Mixed finite elements for numerical weather prediction
in Journal of Computational Physics
Cotter C
(2016)
Embedded discontinuous Galerkin transport schemes with localised limiters
in Journal of Computational Physics
Cotter C
(2014)
A finite element exterior calculus framework for the rotating shallow-water equations
in Journal of Computational Physics
Cotter CJ
(2016)
Mixed finite elements for global tide models.
in Numerische mathematik
McRae A
(2016)
Automated Generation and Symbolic Manipulation of Tensor Product Finite Elements
in SIAM Journal on Scientific Computing
McRae A
(2014)
Energy- and enstrophy-conserving schemes for the shallow-water equations, based on mimetic finite elements
in Quarterly Journal of the Royal Meteorological Society
Melvin T
(2013)
A two-dimensional mixed finite-element pair on rectangles
in Quarterly Journal of the Royal Meteorological Society
Description | Developed an approach to numerical schemes for numerical weather prediction and climate modelling that preserves all the required properties of the existing UK Met Office, but is compatible with massively parallel computers. |
Exploitation Route | This project is in close partnership with the UK Met Office, the main output is the proposal of numerical schemes that will be used in Phase II of the dynamical core development process for the Unified Model. |
Sectors | Environment |
Description | The "GungHo" project to develop a new dynamical core for the UK Met Office weather and climate model is now developing the methods we invented in this project into a fully 3D dynamical core, which is targetting operational use in the early 2020s. The compatible finite element approach developed at Imperial has been selected as the basis for the new dynamical core and will reach operational use in 2025 subject to positive science assessments. |
First Year Of Impact | 2014 |
Sector | Digital/Communication/Information Technologies (including Software),Environment |
Impact Types | Societal |
Description | A scalable dynamical core for Next Generation Weather and Climate Prediction - Phase 2 |
Amount | £367,916 (GBP) |
Organisation | Research Councils UK (RCUK) |
Sector | Public |
Country | United Kingdom |
Start | 03/2013 |
End | 02/2015 |
Description | Standard Grant: Improving Prediction of Fronts |
Amount | £379,737 (GBP) |
Funding ID | NE/K012533/1 |
Organisation | Natural Environment Research Council |
Sector | Public |
Country | United Kingdom |
Start | 01/2014 |
End | 01/2017 |
Description | Standard Grant: Moving meshes for global atmospheric modelling |
Amount | £128,254 (GBP) |
Funding ID | NE/M013634/1 |
Organisation | Natural Environment Research Council |
Sector | Public |
Country | United Kingdom |
Start | 09/2015 |
End | 08/2018 |
Description | Ongoing colloboration with UK Met Office staff |
Organisation | Meteorological Office UK |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We have developed several collaborative interactions with UK Met Office staff |
Start Year | 2011 |
Title | Gusto |
Description | A Python library for compatible finite element dynamical cores |
Type Of Technology | Software |
Year Produced | 2016 |
Open Source License? | Yes |
Impact | This software is providing a testbed for the development of the Gung Ho dynamical core for the Met Office forecast model. |
URL | http://firedrakeproject.org/gusto/ |
Title | Slicemodels |
Description | This is a code for benchmarking our suite of compatible finite element methods for numerical weather prediction in a vertical slice configuration. |
Type Of Technology | Software |
Year Produced | 2015 |
Open Source License? | Yes |
Impact | This tool is being used to benchmark numerical schemes for the NERC/Met Office/STFC UK Dynamical Core project ("Gung Ho"). |
URL | https://bitbucket.org/colinjcotter/slicemodels |
Title | dcore |
Description | Software implementing a numerical model for a 3D dynamical core on the sphere using compatible finite element methods. |
Type Of Technology | Software |
Year Produced | 2016 |
Open Source License? | Yes |
Impact | This software is being used to benchmark numerical algorithms being developed for the UK Met Office forecast model. |
URL | https://github.com/firedrakeproject/dcore |
Description | ICMS Public talk |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Public/other audiences |
Results and Impact | As part of the International Centre for Mathematical Sciences workshop we organised in Edinburgh, we hosted a public talk on climate uncertainty given by David Stainforth. The idea was to engage the public with the importance of mathematics in climate research, particularly in the combination of climate/weather models and statistics in order to understand and quantify uncertainty. We received excellent feedback about the talk through the ICMS. |
Year(s) Of Engagement Activity | 2015 |
Description | Maths Foresees workshop |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | National |
Primary Audience | Professional Practitioners |
Results and Impact | Workshop resulted in collaborative projects between academics and stakeholders, funded through the Maths Foresees network, and forged new potential collaborations for future project calls. Amongst the various activities, I started a new engagement with HR Wallingford on a flooding project. |
Year(s) Of Engagement Activity | 2015 |
URL | http://www1.maths.leeds.ac.uk/mathsforesees/workshopleeds2015.html |
Description | Princes Teaching Trust |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | Regional |
Primary Audience | Professional Practitioners |
Results and Impact | I had fruitful discussions with teachers at the event who got ideas of how to engage students with numerical analysis topics by discussing our work. I received very complementary written feedback from teachers via the Prince's Teaching Trust after the event, who said that they would use examples from my talk in their teaching to inspire KS4/5 students. |
Year(s) Of Engagement Activity | 2015 |