juliensimon/auroral-electrojet-index

Auroral Electrojet (AE) Index

Credit: NASA

Part of a dataset collection on Hugging Face.

Dataset description

Hourly Auroral Electrojet indices from WDC Kyoto — measures auroral zone magnetic activity driven by magnetospheric substorms.

The AE index measures auroral zone magnetic activity caused by enhanced ionospheric currents flowing in the auroral oval. It is derived from geomagnetic variations at 10-13 stations along the auroral zone. The AE family includes four indices:

• AE (Auroral Electrojet): overall auroral activity (AU - AL)
• AU (Auroral Upper): measures eastward electrojet intensity
• AL (Auroral Lower): measures westward electrojet intensity
• AO (Auroral Origin): baseline level (AU + AL) / 2

AE complements the Dst index (ring current) by specifically tracking substorm-driven auroral activity, which is critical for high-latitude communications and power grids.

This dataset is suitable for time-series forecasting, tabular regression tasks.

Schema

Column	Type	Description	Sample	Null %
datetime	datetime64[ns]	Timestamp of 1-minute measurement averaged to hourly cadence (UTC); coverage starts 2021	2021-01-01 00:00:00	0.0%
ae_index	int64	Auroral Electrojet index in nT — range of H-component variation (AU - AL); quiet: <200, substorm: >300, active: >500 nT	29	0.0%
au_index	float64	Auroral Upper index in nT — eastward electrojet intensity; typically 0-1000 nT	15.0	2.6%
al_index	float64	Auroral Lower index in nT — westward electrojet intensity; typically 0 to -2000 nT; strongly negative = substorm	-14.0	2.6%
ao_index	float64	Auroral Overall index in nT — (AU + AL) / 2; substorm activity proxy	1.0	2.6%
quality	str	Data quality: 'provisional' (pending processing) or 'realtime' (near-real-time, subject to revision)	realtime	0.0%
is_active	bool	True if AE >= 500 nT, indicating active auroral substorm conditions	False	0.0%
activity_level	category	Derived category: quiet (<100), moderate (100-300), active (300-500), minor_storm (500-1000), major_storm (>1000 nT)	quiet	0.0%

Quick stats

• 45,648 hourly readings (2021-01-01 to 2026-03-22)
• 4,313 active hours (AE >= 500 nT)
• Peak AE: 2597 nT

Usage

from datasets import load_dataset

ds = load_dataset("juliensimon/auroral-electrojet-index", split="train")
df = ds.to_pandas()

from datasets import load_dataset

ds = load_dataset("juliensimon/auroral-electrojet-index", split="train")
df = ds.to_pandas()

# AE/AL time series during a geomagnetic storm
import matplotlib.pyplot as plt

storm = df[(df["datetime"] >= "2024-05-10") & (df["datetime"] <= "2024-05-15")]
fig, ax = plt.subplots(figsize=(12, 4))
ax.plot(storm["datetime"], storm["ae_index"], label="AE", color="red")
ax.plot(storm["datetime"], storm["al_index"], label="AL", color="blue")
ax.axhline(500, color="gray", linestyle="--", alpha=0.5, label="Active threshold")
ax.legend()
ax.set_ylabel("nT")
ax.set_title("Auroral Electrojet during May 2024 Geomagnetic Storm")
plt.tight_layout()
plt.show()

# Activity distribution
df["activity_level"].value_counts().plot.bar()
plt.title("AE Activity Level Distribution")
plt.show()

Data source

https://wdc.kugi.kyoto-u.ac.jp/aeasy/

Update schedule

Daily at 19:00 UTC

Related datasets

• juliensimon/dst-index

• juliensimon/space-weather-indices

• juliensimon/geomagnetic-kp-index

If you find this dataset useful, please consider giving it a like on Hugging Face. It helps others discover it.

About the author

Created by Julien Simon — AI Operating Partner at Fortino Capital. Part of the Space Datasets collection.

Citation

@dataset{auroral_electrojet_index,
  title = {Auroral Electrojet (AE) Index},
  author = {juliensimon},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/auroral-electrojet-index},
  publisher = {Hugging Face}
}

License

CC-BY-4.0