juliensimon/omni-solar-wind-parameters

OMNI Hourly Solar Wind Parameters

Credit: NASA

Part of a dataset collection on Hugging Face.

Dataset description

Merged hourly near-Earth solar wind magnetic field, plasma, energetic particle parameters combined with geomagnetic and solar activity indices from NASA's OMNI dataset. The master bridge dataset for space weather analysis -- it time-aligns IMF, solar wind, and geomagnetic response in a single file.

The OMNI dataset from NASA's Goddard Space Flight Center merges solar wind observations from multiple spacecraft (IMP 8, ACE, Wind, DSCOVR, and others) into a single consistent hourly time series at Earth's bow shock nose. It combines interplanetary magnetic field (IMF) components, solar wind plasma parameters, energetic particle fluxes, and geomagnetic activity indices. Key parameter groups include IMF (field magnitude, Bx/By/Bz in GSE and GSM), solar wind plasma (proton density, temperature, bulk flow speed), derived quantities (flow pressure, plasma beta, electric field, Alfven and magnetosonic Mach numbers), geomagnetic indices (Kp, Dst, AE, AL, AU, ap, PC(N)), solar indices (F10.7, sunspot number), and energetic particles (proton fluxes at >1 to >60 MeV).

A key feature of the OMNI processing is the time-shifting of upstream spacecraft data to the Earth's bow shock nose. Observations from monitors at the L1 Lagrange point (ACE, Wind, DSCOVR -- roughly 1.5 million km upstream) are propagated to the bow shock using the measured solar wind speed, ensuring temporal alignment with the geomagnetic indices they drive.

The derived quantities encode important plasma physics. Plasma beta distinguishes magnetically dominated structures such as magnetic clouds (beta << 1) from the ambient solar wind (beta ~ 1). The Alfven Mach number characterizes how supersonic the flow is relative to the Alfven wave speed. The convective electric field (-V x B) quantifies magnetic flux transport toward the magnetopause and is a key input to empirical geomagnetic activity models.

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

Schema

Column	Type	Description	Sample	Null %
datetime	datetime64[us]	Observation timestamp (UTC, hourly cadence). OMNI data begins 1963 and is updated daily.	1963-01-01 00:00:00	0.0%
bartels_rotation_number	float64	Bartels solar rotation number: sequential count of 27-day rotation periods; used to align data with the solar rotation cycle.	1771.0	1.1%
b_magnitude_avg_nt	float64	Average IMF magnitude 1/N SUM |B| (nT); scalar average of field magnitude over the hour.	4.5	23.3%
b_magnitude_vector_nt	float64	Magnitude of the hourly-averaged field vector (nT); differs from b_magnitude_avg_nt when the field direction varies within the hour.	3.4	23.3%
b_lat_angle_gse_deg	float64	Latitude angle of the average IMF vector in GSE coordinates (degrees); +90 = northward, -90 = southward.	3.4	23.3%
b_lon_angle_gse_deg	float64	Longitude angle of the average IMF vector in GSE coordinates (degrees); 0 = sunward, 180 = anti-sunward.	154.0	23.3%
bx_gse_nt	float64	IMF Bx component in GSE/GSM coordinates (nT); positive sunward along the Sun-Earth line. Bx is identical in GSE and GSM.	-3.0	23.3%
by_gse_nt	float64	IMF By component in GSE coordinates (nT); positive dawnward (opposite to Earth's orbital motion).	1.5	23.3%
bz_gse_nt	float64	IMF Bz component in GSE coordinates (nT); positive northward (perpendicular to ecliptic).	0.2	23.3%
by_gsm_nt	float64	IMF By component in GSM coordinates (nT); GSM rotates with Earth's dipole tilt, important for magnetospheric coupling.	1.5	23.3%
bz_gsm_nt	float64	IMF Bz component in GSM coordinates (nT); negative (southward) Bz drives magnetic reconnection and geomagnetic storms.	-0.2	23.3%
sigma_b_magnitude_nt	float64	RMS standard deviation of |B| within the averaging hour (nT); measures IMF variability.	0.7	26.3%
sigma_b_vector_nt	float64	RMS standard deviation of the field vector magnitude within the hour (nT).	3.1	23.3%
sigma_bx_nt	float64	RMS standard deviation of Bx component, GSE (nT).	1.4	23.4%
sigma_by_nt	float64	RMS standard deviation of By component, GSE (nT).	2.1	23.4%
sigma_bz_nt	float64	RMS standard deviation of Bz component, GSE (nT).	1.8	23.4%
proton_temperature_k	float64	Solar wind proton temperature (K); typical range 10^4-5x10^5 K; elevated in fast streams, depressed in ICMEs.	55488.0	29.9%
proton_density_cm3	float64	Solar wind proton number density (cm^-3); typical 5-10 cm^-3 at 1 AU; spikes during CME sheaths.	10.5	26.9%
flow_speed_kms	float64	Solar wind bulk plasma speed (km/s); slow wind: 350-450 km/s, fast streams: 600-800 km/s.	285.0	24.0%
flow_lon_angle_deg	float64	Flow longitude angle in quasi-GSE coordinates (degrees); small departures from 180 deg indicate non-radial flow.	-2.5	29.6%
flow_lat_angle_deg	float64	Flow latitude angle in GSE coordinates (degrees); small departures from 0 deg indicate north/south deflections.	3.7	36.0%
alpha_proton_ratio	float64	He2+/H+ number density ratio (Na/Np); typical 0.02-0.08; elevated in fast streams and CMEs.	0.04	42.0%
flow_pressure_npa	float64	Solar wind dynamic (ram) pressure 0.5rhov^2 (nPa); typical 1-10 nPa; high values compress the dayside magnetopause.	1.71	26.9%
sigma_t_k	float64	Intra-hour standard deviation of proton temperature (K); reflects solar wind variability within the averaging window.	10200.0	30.6%
sigma_n_cm3	float64	Intra-hour standard deviation of proton density (cm^-3).	1.7	30.7%
sigma_v_kms	float64	Intra-hour standard deviation of flow speed (km/s).	10.0	29.7%
sigma_phi_v_deg	float64	Intra-hour standard deviation of flow longitude angle (degrees).	1.5	32.3%
sigma_theta_v_deg	float64	Intra-hour standard deviation of flow latitude angle (degrees).	1.3	38.4%
sigma_alpha_proton_ratio	float64	Intra-hour standard deviation of the He2+/H+ density ratio.	0.018	42.0%
electric_field_mvpm	float64	Interplanetary electric field component -V x Bz (mV/m); negative (southward Bz) drives magnetospheric energy input; typical range -10 to +10 mV/m.	0.06	28.2%
plasma_beta	float64	Ratio of thermal pressure to magnetic pressure (nkT / B^2/8pi); beta < 1 = magnetically dominated, beta > 1 = thermally dominated.	3.93	32.7%
alfven_mach_number	float64	Solar wind speed divided by Alfven speed; typical ~8-10 at 1 AU; determines bow shock and magnetopause standoff.	10.3	29.9%
kp_index	float64	Planetary geomagnetic 3-hourly Kp index stored as integer x 10 (e.g. 27 = Kp 2.7); scale 0-90; Kp >= 50 = geomagnetic storm.	7.0	1.1%
sunspot_number	float64	International sunspot number (SILSO v2); tracks the 11-year solar cycle; range ~0-300.	33.0	1.2%
dst_index_nt	float64	Disturbance Storm Time ring-current index (nT); 0 = quiet; -30 to -50 nT = minor storm; < -100 nT = intense storm.	-6.0	1.1%
ae_index_nt	float64	Auroral Electrojet AE index (nT) = AU - AL; measures substorm and auroral zone current intensity; 0-2000+ nT.	119.0	6.6%
proton_flux_gt1mev	float64	Energetic proton flux for particles > 1 MeV (1/cm^2 s sr); elevated during solar proton events (SPEs).	415.56	58.3%
proton_flux_gt2mev	float64	Energetic proton flux for particles > 2 MeV (1/cm^2 s sr).	0.3	64.8%
proton_flux_gt4mev	float64	Energetic proton flux for particles > 4 MeV (1/cm^2 s sr).	0.29	64.8%
proton_flux_gt10mev	float64	Energetic proton flux for particles > 10 MeV (1/cm^2 s sr); NOAA SPE threshold: 10 pfu at this energy.	4.39	34.9%
proton_flux_gt30mev	float64	Energetic proton flux for particles > 30 MeV (1/cm^2 s sr).	1.51	34.9%
proton_flux_gt60mev	float64	Energetic proton flux for particles > 60 MeV (1/cm^2 s sr).	0.93	34.9%
ap_index_nt	float64	Linear equivalent of Kp index (nT); 3-hourly; range 0-400 nT; ap >= 100 = major geomagnetic storm.	3.0	1.1%
f107_index_sfu	float64	Solar 10.7 cm radio flux index (SFU, 1 SFU = 10^-22 W/m^2/Hz); solar cycle range ~65-300 SFU; proxy for EUV output.	77.0	1.2%
pc_n_index	float64	Polar Cap (North) magnetic activity index from Thule/Qaanaaq magnetometer; tracks cross-polar-cap potential and substorm precursors.	0.5	21.9%
al_index_nt	float64	Auroral Electrojet lower (AL) index (nT); measures westward electrojet intensity; negative excursions indicate substorm onset.	-19.0	11.3%
au_index_nt	float64	Auroral Electrojet upper (AU) index (nT); measures eastward electrojet intensity; AE = AU - AL.	-2.0	11.3%
magnetosonic_mach_number	float64	Solar wind speed divided by the fast magnetosonic wave speed; determines bow shock geometry; typical ~6-8 at 1 AU.	6.6	32.7%

Quick stats

• 561,024 hourly records (1963-01-01 to 2026-12-31)
• 48 parameters spanning IMF, solar wind, geomagnetic indices, and energetic particles
• Bz coverage: 76.7%, flow speed: 76.0%, Dst: 98.9%
• Standard reference dataset for solar wind-magnetosphere coupling studies

Usage

from datasets import load_dataset

ds = load_dataset("juliensimon/omni-solar-wind-parameters", split="train")
df = ds.to_pandas()

from datasets import load_dataset

ds = load_dataset("juliensimon/omni-solar-wind-parameters", split="train")
df = ds.to_pandas()

# Southward IMF (Bz < 0) and geomagnetic storms (Dst < -50)
storms = df[(df["bz_gsm_nt"] < -5) & (df["dst_index_nt"] < -50)]
print(f"Storm hours with strong southward IMF: {len(storms):,}")

# Solar wind speed distribution
print(df["flow_speed_kms"].describe())

# Plasma beta vs Alfven Mach number
import matplotlib.pyplot as plt
sub = df[["plasma_beta", "alfven_mach_number"]].dropna()
plt.scatter(sub["plasma_beta"], sub["alfven_mach_number"], s=0.1, alpha=0.1)
plt.xlabel("Plasma Beta")
plt.ylabel("Alfven Mach Number")
plt.xscale("log")
plt.yscale("log")
plt.title("OMNI: Plasma Beta vs Alfven Mach Number")
plt.show()

Data source

https://omniweb.gsfc.nasa.gov/

Related datasets

• juliensimon/solar-wind

• juliensimon/dst-index

• juliensimon/geomagnetic-kp-index

• juliensimon/auroral-electrojet-index

• juliensimon/f107-solar-flux

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{omni_solar_wind_parameters,
  title = {OMNI Hourly Solar Wind Parameters},
  author = {juliensimon},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/omni-solar-wind-parameters},
  publisher = {Hugging Face}
}

License

CC-BY-4.0