SDOFMv2: A Multi-Instrument Foundation Model for the Solar Dynamics Observatory with Transferable Downstream Applications

SDOFMv2 is an advanced multi-instrument foundation model for analyzing Solar Dynamics Observatory (SDO) data, designed to drive large-scale, data-driven heliophysics research. Building on the original SDOFM framework, this version improves spatial coherence and global consistency by addressing limitations in temporal coverage and reconstruction artifacts.

A Masked Autoencoder (MAE) built on a Vision Transformer (ViT) backbone is used for pretraining. During training, a% of image patches are masked; the remaining (100 - a)% are processed by the encoder. The decoder then reconstructs all patches, optimized via a customized loss function.

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Table of Contents

• Getting Started
• Repository Structure
• Data Preparation
• Training & Evaluation
• Results & Visualizations
• Citation
• Acknowledgments

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Getting Started

For full documentation, please visit sdofmv2.readthedocs.io.

Prerequisites

• Python 3.11+
• NVIDIA GPU + CUDA toolkit (recommended for training)

Installation

We use mamba (or conda) for fast dependency resolution.

Hardware Note: sdofmv2_environment.yml is configured for CUDA 12.8 by default. If your system requires a different CUDA version (e.g., 11.8), edit the pip section in sdofmv2_environment.yml before running setup — change cu128 to the appropriate tag (e.g., cu118).

# Clone the repository
git clone https://github.com/Joaggi/sdofmv2.git
cd sdofmv2

# Create and activate the environment
# (installs PyTorch and the local package automatically)
mamba env create -f sdofmv2_environment.yml
mamba activate sdofmv2

Pretrained Weights

Pretrained model checkpoints are available on Hugging Face:

# Using the Hugging Face Hub
mamba install huggingface_hub -c conda-forge
huggingface-cli download joseph-gallego/sdofmv2

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Repository Structure

.
├── configs/                    # YAML configurations for experiments
│   ├── downstream/             # Configs for downstream tasks (F10.7, solar wind)
│   └── pretrain/               # Configs for MAE pretraining (AIA, HMI)
├── notebooks/                  # Jupyter notebooks for analysis and visualization
│   ├── analysis/               # Attention maps, PCA, and masking analysis
│   └── downstream_apps/        # Downstream application demos (F10.7, missing data)
├── scripts/                    # Executable training and evaluation scripts
│   ├── pretrain.py             # Main pretraining script
│   ├── finetuning_*.py         # Downstream finetuning scripts
│   ├── test.py                 # Checkpoint evaluation script
│   └── download_data.py        # Resumable dataset downloader
├── src/
│   └── sdofmv2/
│       ├── core/               # Base model architectures and modules
│       ├── tasks/              # PyTorch Lightning modules for downstream tasks
│       └── utils/              # Helper functions, physical constants, and metrics
├── pyproject.toml              # Project metadata and build dependencies
└── sdofmv2_environment.yml     # Mamba environment definition

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Data Preparation

SDOFMv2 uses the SDOMLv2 dataset — a curated, multi-instrument dataset for the Solar Dynamics Observatory, hosted on NASA's HDRL S3 bucket. Data is streamed via s3fs and stored in the Zarr format.

Dataset Components

Component	Instrument	Data Type	Approx. Size	Description
aia	AIA	EUV Images	~7.2 TB	9 extreme ultraviolet channels capturing the solar atmosphere
hmi	HMI	Magnetograms	~713 GB	3-component vector magnetic field (Bx, By, Bz) for the solar photosphere

Storage: Zarr datasets require significant local disk space. Verify your target drive has sufficient capacity before downloading.

Downloading the Data

The download script is resumable — it checks for existing local files and only fetches what's missing.

# Download AIA only
python scripts/download_data.py --target /path/to/your/storage --component aia

# Download HMI only
python scripts/download_data.py --target /path/to/your/storage --component hmi

# Download the full dataset
python scripts/download_data.py --target /path/to/your/storage --component both

Zarr Directory Layout

After download, the data is organized as follows:

data/
├── sdomlv2.zarr/                # AIA multi-channel dataset
│   ├── .zgroup                  # Group hierarchy metadata
│   ├── 2010/
│   │   ├── 131A/                # EUV channel (131 Å)
│   │   ├── 1600A/               # EUV channel (1600 Å)
│   │   └── ...                  # Other AIA channels (193, 211, 304, etc.)
│   └── ...
└── sdomlv2_hmi.zarr/            # HMI magnetic field dataset
    ├── .zgroup
    └── 2010/
        ├── Bx/                  # Magnetic field component
        └── By/                  # Magnetic field component

Unlike monolithic file formats (e.g., .fits), the chunked Zarr layout enables high-speed random access — data loaders can read specific time slices or channels without loading the full multi-terabyte dataset into memory.

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Training & Evaluation

Pretraining

python scripts/pretrain.py --config-name pretrain_mae_AIA.yaml

Evaluation

python scripts/test.py --config-name pretrain_mae_AIA.yaml

Downstream Finetuning

# Example: solar wind forecasting
python scripts/finetuning_solarwind.py --config-name finetune_solarwind_config.yaml

Configuration files for all tasks are in configs/downstream/. Notebook-based walkthroughs are available in notebooks/downstream_apps/.

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Results & Visualizations

Our MAE trained on AIA data successfully reconstructs SDO solar images at high quality.

Row 1: Ground-truth images. Row 2: Reconstructions at 0% masking ratio. Row 3: Reconstructions at 50% masking ratio.

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Citation

If SDOFMv2 is useful in your research, please cite:

@misc{sdofmv2,
  author    = {Hong, Jinsu and Martin, Daniela and Gallego, Joseph},
  title     = {SDOFMv2: A Multi-Instrument Foundation Model for the Solar Dynamics Observatory with Transferable Downstream Applications},
  year      = {2026},
  publisher = {GitHub},
  journal   = {GitHub repository},
  howpublished = {\url{https://github.com/Joaggi/sdofmv2}},
  note      = {Jinsu Hong, Daniela Martin, and Joseph Gallego contributed equally to this work}
}

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Contributing

Contributions, bug reports, and feature requests are welcome! Please check the issues page or open a pull request.

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Acknowledgments

This work builds on the SDOFM framework developed by Trillium Technologies Inc. We thank the creators of SDOMLv2 for providing the curated multi-wavelength training data, and the NASA Solar Dynamics Observatory mission for open data access.