Oceananigans.jl: A Julia library that achieves breakthrough resolution, memory and energy efficiency in global ocean simulations

TL;DR

Oceananigans.jl, a Julia-based library, enables high-resolution, energy-efficient global ocean simulations, significantly advancing climate modeling capabilities with unprecedented resolution and resource efficiency.

Contribution

The paper introduces Oceananigans.jl, achieving breakthrough resolution, memory, and energy efficiency in global ocean simulations, surpassing current models and enabling routine high-resolution climate simulations.

Findings

Global ocean simulation at 488m resolution reaching 15 SYPD.

Breakthrough energy efficiency with 0.95 SYPD at 1.7 km resolution.

Highest horizontal resolutions used by IPCC-class models achieved.

Abstract

Climate models must simulate hundreds of future scenarios for hundreds of years at coarse resolutions, and a handful of high-resolution decadal simulations to resolve localized extreme events. Using Oceananigans.jl, written from scratch in Julia, we report several achievements: First, a global ocean simulation with breakthrough horizontal resolution -- 488m -- reaching 15 simulated days per day (0.04 simulated years per day; SYPD). Second, Oceananigans simulates the global ocean at 488m with breakthrough memory efficiency on just 768 Nvidia A100 GPUs, a fraction of the resources available on current and upcoming exascale supercomputers. Third, and arguably most significant for climate modeling, Oceananigans achieves breakthrough energy efficiency reaching 0.95 SYPD at 1.7 km on 576 A100s and 9.9 SYPD at 10 km on 68 A100s -- the latter representing the highest horizontal resolutions employed by current IPCC-class ocean models. Routine climate simulations with 10 km ocean components are within reach.