ENDGame: A new dynamical core for seamless atmospheric prediction
Research news article published in July 2014.
The dynamical core
Modern computer models of the atmosphere include many complex physical processes that each have local influences and feed back into the general circulation. At the heart of these models, however, is the solution of the dynamical equations of motion (Newton's laws applied to a gas). For this reason, the model component that solves these equations is called the "dynamical core".
The dynamical core used in Unified Model prior to July 2014 is known as "New Dynamics" and was first introduced in 2002. The introduction of New Dynamics was a major step forward as it solved an unprecedentedly accurate set of equations. This allowed us to pursue our seamless modelling approach by using the same dynamical core for very high-resolution weather forecasts as for centuries-long climate projections.
To solve the New Dynamics equations both stably and quickly, we needed to apply artificial damping, which removes detail from the forecasts. In addition, its scalability (the increased speed achieved by using more computer processors) was approaching its limit, which impeded our ability to run higher resolution models on our supercomputers.
To improve these aspects of the model whilst maintaining the benefits of New Dynamics, our Dynamics Research team and Prof. John Thuburn from the University of Exeter developed ENDGame (Even Newer Dynamics for General atmospheric modelling of the environment).
This development took nearly 10 years and in the past two years staff from across the Met Office have tested and evaluated its impact and prepared our operational systems for its implementation. ENDGame is now being used for global weather and climate prediction work and we will move our regional and seasonal prediction systems to use ENDGame over the next year.
In global models, ENDGame's improved accuracy and reduced damping produces more detail in individual synoptic features such as cyclones, fronts, troughs and jet stream winds. In the tropics, a combination of ENDGame, increased resolution and improvements to the model's physics provides unprecedented improvements to our predictions of tropical cyclone intensity and position.
ENDGame's improved scalability has allowed us to increase the resolution of our global weather forecasts which provides additional improvements to forecast accuracy. It will also allow us to further increase the model's resolution when our supercomputer capacity increases.
In a sense ENDGame finishes the work that New Dynamics started, but the development of our dynamical cores doesn't end here. Research has already started on the next-generation dynamical core (named GungHo) which we expect to replace ENDGame in about 10 years.
Being developed in collaboration between Met Office scientists, academics from across the UK and computational scientists from the Hartree Centre, GungHo will be part of a completely new model that will deliver the step change in scalability required to continue to exploit future generations of computers. This will ensure that, together with our collaborators, we can continue to improve our weather and climate services into the next decade and beyond.