Credit: Calcul Québec

Last summer, the Ministère de l’Économie, de l’Innovation et de l’Énergie (MEIE) awarded funding to Ouranos for the purchase of a server cluster, commonly referred to as a supercomputer.

Ouranos produces climate simulations to generate climate projections. Behind this scientific work lies a plethora of calculations, which place a considerable burden on computer hardware. 

That means Ouranos climate scientists require a great deal of computing capacity to be able to model, analyze and quantify climate phenomena. The new Ouranos supercomputer adds to this computing capacity.

This equipment is held by Calcul Québec, a non-profit organization offering high-performance computing services and expertise to universities and research centres. 

The benefits of high-performance computing

Climate simulations require thousands of times more computing power than a desktop computer offers. This is due to the astronomical quantity of inputs, calculations and variables produced and managed. 

To produce a simulation, a climate model must be run, which solves the complex mathematical equations of fluid mechanics to describe the behaviour of the atmosphere and its interactions with the Earth’s surface, including:

• The oceans

• Ice

• Lakes

• Soils 

• Vegetation 

• Snow

• Urban areas 

This kind of model also has to work with data on the chemical composition of the atmosphere, such as greenhouse gases, ozone and aerosols, as well as physical characteristics like the amount of solar energy received and geophysical data on the Earth’s surface. 

These simulations produce over a hundred climate variables, including temperature, humidity, wind, barometric pressure and precipitation, for each point on a three-dimensional grid that circles the Earth. Each of these climate variables is then calculated at 5- to 20-minute intervals over a simulated time period of up to 150 years. The result is a simulation of planet Earth and its climate conditions. 

 

Figure 1.  Diagram of a global climate model (left) | Diagram of a regional climate model (right)

Simulating North America

Ouranos’ main simulation work is on North America. To do this, we divide the continent into sub-domains for the calculations. These sub-domains, which are made up of several calculation cubes, form a three-dimensional grid that extends horizontally over the entire area and vertically into the atmosphere. 

Figure 2: Diagram of the calculation cubes. Each cube represents a part of the climate system and also interacts with neighboring cubes.

This simulation work requires what is known as parallel computing, i.e. operations calculated simultaneously on several processors. The sub-domains are calculated at the same time and interact with each other. 

Optimizations made possible by the supercomputer

With its 3,328 new computing cores, the supercomputer will facilitate the integration and optimization of Ouranos’ climate information generation processes. This allows the consortium to move part of its analysis capacity, which was previously carried out on fewer, less powerful servers in its own offices, to Calcul Québec. This will speed up the extraction of scientific information and data from simulations. 

This increased analysis capacity will enable Ouranos to optimize various data processing operations to enhance its existing products and create new ones, including scientific publications and climate indicators for Quebec, such as ice, wind and snow cover on the ground. 

The consortium will also be able to update its climate portals, Climate Portraits and PAVICS, more frequently, and include more climate variables to meet user needs. 

With the acceleration of climate change and the pressing need to adapt to it, the new cluster is a major advance for Ouranos. This supercomputer will enable Ouranos  to play a greater role in regional climate modelling and to provide effective support for decision-makers and researchers working in the field of climate change adaptation in Quebec.