I will describe our early experiences using Trillium to build the next-generation of Lat–Lon–Cap (LLC) global ocean simulations, culminating in LLC8640, a 1/96° (~1 km) global “nature run” that, once complete, will be the highest-resolution realistic ocean model ever produced. The model advances well beyond the widely used but biased LLC4320 by increasing vertical and horizontal resolution, updating global bathymetry, enabling a nonlinear free surface, adding explicit ice-shelf cavities around Greenland and Antarctica, applying hourly atmospheric forcing, incorporating realistic river discharge, and introducing accurate astronomical tides. These improvements directly address long-standing issues in earlier LLC models, including a misplaced Gulf Stream, a crude representation of Antarctic shelf currents, and anemic tropical instability waves.

The workflow uses a staged spin-up: first LLC1080 (1/12°) to settle major currents and the global kinetic-energy field; LLC4320 (1/48°) to allow mesoscale and submesoscale structures to sharpen; and finally a one-month LLC8640 integration generating several petabytes of hourly 3-D fields of velocity, temperature, and salinity. The resulting dataset offers an unprecedented benchmark for studies of internal tides and waves, turbulence parameterization, and SWOT-era sea-surface height variability. All configurations, tools, and outputs will be openly released, positioning this Canada-led effort as a major global resource for oceanography and climate modeling.