Samudra: An AI Global Ocean Emulator for Climate

Abstract

AI emulators for forecasting have emerged as powerful tools that can outperform conventional numerical predictions. The next frontier is to build emulators for long climate simulations with skill across a range of spatiotemporal scales, a particularly important goal for the ocean. Our work builds a skillful global emulator of the ocean component of a state-of-the-art climate model. We emulate key ocean variables, sea surface height, horizontal velocities, temperature, and salinity, across their full depth. We use a modified ConvNeXt UNet architecture trained on multidepth levels of ocean data. We show that the ocean emulator - Samudra - which exhibits no drift relative to the truth, can reproduce the depth structure of ocean variables and their interannual variability. Samudra is stable for centuries and 150 times faster than the original ocean model. Samudra struggles to capture the correct magnitude of the forcing trends and simultaneously remains stable, requiring further work.

Type
Publication
GRL
Surya Dheeshjith
Surya Dheeshjith
AI Scientist, Capital One
Adam Subel
Adam Subel
PhD Student

My research interests include distributed robotics, mobile computing and programmable matter.

Shubham Gupta
Shubham Gupta
ML Engineer at Rivet.us

My research interests include distributed robotics, mobile computing and programmable matter.

Laure Zanna
Laure Zanna
Joseph B. Keller and Herbert B. Keller Professor in Applied Mathematics; Professor of Mathematics and Data Science

My research interests include Climate Dynamics, Physical Oceanography, Applied Math, and Data Science.