@article{valva2026more,
  title = {A more predictable Madden-Julian Oscillation index derived from Koopman spectral analysis},
  author = {Claire Valva and Edwin P. Gerber},
  year = {2026},
  eprint = {2609.19435},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.19435},
}