| --- |
| license: bsd-3-clause |
| tags: |
| - climate |
| - emulator |
| - e3sm |
| - ace |
| - samudra |
| --- |
| |
| # E3SMv3 emulator checkpoints for the E3SM AI group hackathon, 25 September 2026 |
|
|
| > **Not fit for forcing or scenario experiments.** Both checkpoints reproduce the E3SMv3 historical run well |
| > when the other half of the climate system is handed to them, but neither should be trusted to respond to a |
| > change in forcing. Use them to study how an emulator represents the climate, not what the climate does. |
| > Results from them show how the model *represents* forcing. |
|
|
| | Folder | Checkpoint | Fit for | Not fit for | |
| | --- | --- | --- | --- | |
| | `E05-FT-S01/` | `E05-FT.aug26.atm.A3_B16_C1_L0_O5_W0_X0.S01`, atmosphere, noise-conditioned SFNO (8 blocks × 384 channels), 1°, 6-hourly, SST prescribed | Historical runs with prescribed SST; looking inside the network | Any forcing experiment | |
| | `E11-FT-S01/` | `E11-FT.aug26.ocn.A0_B16_C0_L0_O5_W0_X0.S01`, ocean, Samudra U-Net, 1°, 5-daily, surface fluxes prescribed | Replaying the historical run from reference fluxes; looking inside the network | Any change to the fluxes | |
|
|
| These are the checkpoints the latents in |
| [E3SM-Project/aigs-hack-sep26-latents](https://huggingface.co/datasets/E3SM-Project/aigs-hack-sep26-latents) |
| were recorded from. E05-FT S01 is not the shipped atmosphere (S03). |
|
|
| ## Run an experiment yourself |
|
|
| The `kit/` folder holds what a 2015 atmosphere run needs besides the checkpoint: the initial condition |
| (2015-01-03 12:00), two months of forcing (the inputs only), and configs for the control and each intervention. |
| One run uses about 4 GB of GPU memory. |
|
|
| ```console |
| $ pip install "fme @ git+https://github.com/E3SM-Project/ace@e3sm/exps/hist-v2026.8.0" |
| $ hf download E3SM-Project/aigs-hack-sep26-models --local-dir aigs-models && cd aigs-models |
| $ python -m fme.ace.inference kit/configs/atm-co2x1.25.yaml |
| ``` |
|
|
| | Config | Intervention | |
| | --- | --- | |
| | `atm-ctrl.yaml` | none | |
| | `atm-co2x1.25.yaml`, `atm-co2x0.8.yaml` | `overwrite.multiply_scalar.global_mean_co2` | |
| | `atm-p4K.yaml` | `overwrite.add_scalar.TS: 4.0` | |
| | `atm-aerofrz.yaml` | aerosol diagnostics swapped for their 1965 values (`kit/forcing-aerofrz/`) | |
|
|
| Every config sets `seed: 0`. Keep it: the model is stochastic, and a shared seed is what makes two runs |
| comparable node for node. Change the intervention by editing the `overwrite` block; make it longer with |
| `n_forward_steps` (the forcing covers January and February 2015). |
|
|
| To record the latents as well, and to steer a layer along a feature, use the exporter in the kit |
| (`kit/export_fme_latents.py`; it needs [xaig](https://pypi.org/project/xaig/) 0.3 or later in the same |
| environment): |
|
|
| ```console |
| $ python kit/export_fme_latents.py kit/configs/atm-ctrl.yaml --out my-run --steps 20 \ |
| --steer 0:sae_L00.npz:FEATURE:3 # push one SAE feature of layer 0 by +3 at every node |
| ``` |
|
|
| It reproduces the published latents bit for bit. `kit/vectors/` holds the three steering vectors some of the |
| published runs used; the |
| [dataset card](https://huggingface.co/datasets/E3SM-Project/aigs-hack-sep26-latents#reproduce-a-run) gives the |
| command for every run, says how the vectors were made, and how to |
| [make your own](https://huggingface.co/datasets/E3SM-Project/aigs-hack-sep26-latents#making-your-own-steering-vector): |
| a difference between two runs, a contrast within one (rain against no rain, land against ocean), a basis |
| direction, or a probe. |
|
|
