CTD rosette at sunrise aboard the research vessel Nancy Foster (Credit: Cassia Busch, USGS, Public Domain)
SUBTOPIC

Fluid Dynamics & Thermohaline Flow

Modeling the ocean's conveyor belt before its tipping point arrives.

Image: Cassia Busch, USGS

Simulating the Atlantic's Conveyor Belt

The AMOC is not a single current but an emergent property of the entire Atlantic's density structure, driven by salinity and heat gradients that unfold over decades. Capturing its behavior — and the sub-mesoscale eddies that modulate it at 10 km scales — requires eddy-resolving CFD solvers running at petascale on a global ocean grid. Malgukke provides the CPU/GPU fabric and low-latency interconnect needed to couple these fine-scale ocean dynamics into century-length climate projections without the numerics drifting off course.

HPC Solution Architecture: Observation to Circulation Forecast

An eddy-resolving ocean circulation pipeline, comparable to GFDL's MOM6-based ocean models:

Ocean Observations Argo floats, moorings, altimetry CFD Core (MOM6) CPU Nodes Density & pressure solver GPU Nodes 10km eddy resolution Heat & Salt Transport tracking AMOC Strength Index & tipping indicators Circulation Forecast & risk assessment New float and mooring data reinitialize the next assimilation cycle

Running on the TOP500: Gaea

TOP500-LISTED — NOAA / ORNL

Gaea (C5/C6) — NOAA National Climate-Computing Research Center, Oak Ridge National Laboratory

Gaea is a pair of HPE Cray EX systems listed on TOP500.org's registry of supercomputing sites, with an aggregate peak capability exceeding 20 petaflops and over 150 petabytes of fast-access storage. Gaea's principal user is NOAA's Geophysical Fluid Dynamics Laboratory (GFDL), which develops and runs the MOM6 ocean model and coupled climate configurations such as CM4 and SPEAR — the exact ocean circulation workloads described on this page.

Yes — this is a real, currently operating system dedicated to ocean and climate research, directly used by GFDL for the circulation modeling described here.

20+
Peak Petaflops (Aggregate)
150+
Petabytes of Storage

Voices from the Field

Researchers tracking the state of the Atlantic's overturning circulation:

Stefan Rahmstorf

Potsdam Institute for Climate Impact Research (PIK)

On why the probability of an AMOC tipping point being reached this century is now estimated at over 50 percent.

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Woods Hole Oceanographic Institution

Ocean in Motion research group

On the range of scientific views on whether — and when — the AMOC could undergo an abrupt transition this century.

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