---
frameworks: PyTorch
language:
- en
license: apache-2.0
tags:
- OneScience
- Earth Science
- Weather Forecast
- Medium-Range Weather Forecast
- ERA5
- FuXi
tasks: []
datasets:
- OneScience/ERA5
---
<p align="center">
  <strong>
    <span style="font-size: 30px;">FuXi_v21</span>
  </strong>
</p>

# Model Introduction

FuXi 2.1 is a global deterministic machine-learning weather forecast model developed by Fudan University in collaboration with the Shanghai Artificial Intelligence Laboratory (SAIS). Its theoretical basis remains the original FuXi paper.

Paper: FuXi: A cascade machine learning forecasting system for 15-day global weather forecast

https://arxiv.org/abs/2306.12873

# Model Description

The model addresses the excessive smoothing often observed in AI weather forecasts. It aims to produce clearer and more detailed forecast fields, improving the detection of extreme events such as heavy precipitation and strong winds without degrading conventional metrics such as root mean square error (RMSE).

# Use Cases

| Scenario | Description |
| :---: | :--- |
| Global weather forecast training | Train FuXi v2.1 with C85 ERA5 data in HDF5 format. |
| Local quick validation | Use synthetic HDF5 data to check data loading, training, inference, and visualization of inference results. |
| ModelScope / OneCode execution | Download the standalone model package, install dependencies, and run the scripts directly. |
| Multi-GPU training | Run distributed data-parallel training 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/FuXi_v21 --local-dir ./FuXi_v21
cd FuXi_v21
```

### 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 training entry point uses the OneScience `ERA5Dataset`. The data root is specified by `paths.data_root` in `conf/config.yaml`. The OneScience community provides a data slice for interface validation and training:

```bash
hf download --repo-type dataset OneScience-Group/ERA5 --local-dir ./data
```

### Generate Synthetic Data

Real HDF5 files must contain a `fields` dataset, C85 variable attributes, six-hour intervals, and normalization statistics. When real data is unavailable, generate protocol-compatible synthetic files:

```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 saved to `data/checkpoint/model_bak.pth` by default, and metrics are saved to `output/training/metrics.json`.

### Training Weights

This repository provides weights trained on ERA5 reanalysis 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/inference/forecast.nc` by default.

### Evaluation and Visualization

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

The default output is `figures/fuxi21_t2m.png`.

# 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 project is an unofficial forward-graph reproduction of FuXi v2.1. It does not represent official weights or training recipes released by Fudan University.
- This adapted repository is distributed under Apache License 2.0 metadata. ERA5 data, OneScience, and the upstream FuXi implementation remain subject to their respective official licenses and terms of use.