---
frameworks: PyTorch
language:
- en
license: apache-2.0
tags:
- OneScience
- Earth Science
- Climate Simulation
- Global Atmospheric State Simulation
- SFNO
- FV3GFS
tasks: []
datasets:
- FV3GFS
---
<p align="center">
  <strong>
    <span style="font-size: 30px;">Ai2_Climate_Emulator</span>
  </strong>
</p>

# Model Introduction

The AI2 Climate Emulator (ACE) is a global atmospheric state emulator proposed by the Allen Institute for AI (AI2).

Paper: ACE: A fast, scalable foundation model for the atmosphere

https://arxiv.org/abs/2310.02074

# Model Description

This project implements the spherical Fourier neural operator (SFNO) forward graph with PyTorch and `torch_harmonics`. It takes the atmospheric state and external forcings at the current six-hour time step as input, predicts the state at the next time step, and can generate multi-step climate or weather fields autoregressively.

# Use Cases

| Scenario | Description |
| :---: | :--- |
| Global atmospheric state simulation | Train a one-step ACE model with FV3GFS data following the 40/44-channel protocol. |
| Local quick validation | Generate synthetic NPZ files with `scripts/fake_data.py` to check the training, inference, and result-visualization pipeline. |
| ModelScope / OneCode execution | Download the standalone model package, install dependencies, and run the scripts directly. |
| Multi-GPU training | Launch PyTorch DDP with `torchrun`. |

# Usage Guide

## 1. OneCode Usage

Experience intelligent one-click AI4S programming through the OneCode online environment:

[Click to Experience Intelligent One-Click AI4S Programming](https://web-2069360198568017922-iaaj.ksai.scnet.cn:58043/home)

## 2. Manual Installation and Usage

**Hardware Requirements**

- A GPU or DCU is recommended.
- CPU can be used for import and small-scale connectivity verification; full training and inference will be slow.
- DCU users must install DTK in advance. DTK 25.04.2 or above, or the OneScience recommended version matching your cluster, is recommended.

### Download the Model Package

```bash
hf download OneScience-Group/Ai2_Climate_Emulator --local-dir ./Ai2_Climate_Emulator
cd Ai2_Climate_Emulator
```

### Install the Runtime Environment

**DCU Environment**

```bash
# Please activate DTK and CONDA first
conda create -n onescience311 python=3.11 -y
conda activate onescience311
# uv installation is supported
pip install onescience[earth-dcu] -i http://mirrors.onescience.ai:3141/pypi/simple/  --trusted-host mirrors.onescience.ai
```

**GPU Environment**
```bash
# Please activate CONDA first
conda create -n onescience311 python=3.11 -y libstdcxx-ng=12 libgcc-ng=12 gcc_linux-64=12 gxx_linux-64=12
conda activate onescience311
# uv installation is supported
pip install onescience[earth-gpu] -i http://mirrors.onescience.ai:3141/pypi/simple/  --trusted-host mirrors.onescience.ai
```

### Training Data Introduction

The ACE paper uses an ensemble of 11 FV3GFS initial conditions: 10 members for training and one member for validation. The simulations are written at six-hour intervals and regridded to a Gaussian latitude-longitude grid. The original FV3GFS files and NOAA `fregrid` are not included in this model package; users must prepare and convert them to the NPZ format required by the project:

```text
inputs:  [N, 40, H, W]
targets: [N, 44, H, W]
```

When real data is unavailable, generate synthetic data for pipeline validation:

```bash
python scripts/fake_data.py
```

### Training

Single GPU:

```bash
python scripts/train.py
```

Multi-GPU:

```bash
torchrun --nproc_per_node=8 scripts/train.py
```

Training checkpoints are written to `data/checkpoint/model_bak.pt` by default.

### Training Weights

This repository provides weights trained on FV3GFS data in the `weight/` folder. The weight files will be uploaded soon and are expected to be available in the near future.

### Inference

```bash
python scripts/inference.py
```

Inference results are saved to `output/infer/rollout.npz` by default.

### Evaluation and Visualization

```bash
python scripts/result.py
```

Area-weighted RMSE, global mean bias, and PNG figures are written to `output/pic/` by default.

# Official OneScience Resources

| Platform | OneScience Main Repository | Skills Repository |
| --- | --- | --- |
| Gitee | https://gitee.com/onescience-ai/onescience | https://gitee.com/onescience-ai/oneskills |
| GitHub | https://github.com/onescience-ai/OneScience | https://github.com/onescience-ai/oneskills |

# Citation and License

- This repository is a reproduction of the ACE model.