How it works
The board shows what is happening between the Sun and the Earth right now and what it means on the ground: for navigation, power grids, radio, satellites, aurora and living things. Every panel is live; data refreshes every one to ten minutes.
What is on the board
| Panel | What it shows | Refresh |
|---|---|---|
| Solar wind at Earth | Speed, density and the Bz field from the probe at L1, 1.5 million km sunward of Earth. The wind takes 30-60 minutes to arrive from there. The Newell coupling index shows how much energy enters the magnetosphere: negative Bz, a southward field, opens the door. | 1 minute |
| Ejection tracking | Whether a coronal mass ejection, CME, is heading for Earth, when to expect the hit, hits in the last day, NOAA storm watches, flares over 3 days and the 3-day Kp forecast. | 10 minutes |
| Earth now | Map: the aurora zone from the OVATION model, the night side, magnetic observatories with dB/dt field changes over the last 30 minutes. The stronger the changes, the larger the induced currents in long lines. | 10 minutes |
| Impacts | Seven areas: GNSS navigation, power grids and pipelines, HF radio and aviation, satellites, aurora, animals, wellbeing. For each: level, what is happening, what to do and what it is based on. | 5 minutes |
| 24-hour strip | Wind and Bz, the planetary Kp index and the Dst ring current over the last day. Clock in your time zone. | 5 minutes |
Terms in one line
- Kp: planetary index of geomagnetic disturbance, 0..9 for each 3-hour interval. 5 and above counts as a storm, 7 and above as a severe one.
- Dst: the ring current around Earth in nanotesla, from the Kyoto observatory. Below minus 50 a moderate storm, below minus 100 a severe one.
- Bz: the vertical component of the interplanetary field. Negative means southward, and then wind energy enters the magnetosphere.
- dB/dt: the rate of change of the magnetic field at a station, nanotesla per minute. This is what induces currents in grids and pipelines.
- L1: the point between the Sun and the Earth where solar wind probes sit. They give 30-60 minutes of warning.
- CME: coronal mass ejection, a plasma cloud from the Sun. It takes 15 hours to 3 days to reach Earth.
Where the data comes from
| Source | What we take | Delay |
|---|---|---|
| NOAA SWPC, USA | Solar wind from the L1 probe by the minute, Kp by the minute and per 3 hours, the Kp forecast, the WSA-Enlil model, watches and warnings, the R and S scales, flares, the OVATION aurora model | 5-15 minutes |
| WDC Kyoto via NOAA | Hourly Dst, provisional | up to an hour |
| INTERMAGNET via BGS | Observatory magnetic field by the minute, preliminary data; the map shows those that report in near real time | 5-15 minutes |
| NASA DONKI | Catalog of ejections with arrival estimates; used when reachable | hours |
What we can and cannot do
Tested on 30 years of measurements, 1995-2024, the honest way: trained on some years, tested on others.
- The L1 probe gives 30-120 minutes of warning of rising currents at high latitudes. At mid latitudes it adds almost nothing to the station's own history.
- One day ahead, a Kp corridor with a width: the error is a quarter below climatology. Beyond two days the maximum forecast is no better than climatology, and we do not hide it.
- A storm from a coronal mass ejection is not visible a day ahead in any of our layers: NOAA models and the ejection catalog speak to that, and the board shows them rather than its own guess.
- The 27-day recurrence and the equinox season are real: on such days a storm is 2.4 times more likely. Moon phases and slow terrestrial series showed no link to solar activity.
How impacts are computed
Levels for each area come from rules over current readings: Kp and Dst, wind at L1, NOAA flare and proton scales, field changes at observatories with a threshold by station latitude, the aurora model and the 2-day Kp forecast. For animals and wellbeing the basis is statistical, and it says so right there.
Acknowledgements and data terms
Solar wind, Kp indices, forecasts, the WSA-Enlil and OVATION models, flares and scales: NOAA Space Weather Prediction Center (swpc.noaa.gov), US government data in the public domain.
Magnetic observatory readings come through INTERMAGNET and the British Geological Survey. We thank the national institutes that support the observatories and INTERMAGNET for promoting high standards of magnetic observatory practice (intermagnet.org). The data is preliminary.
The Dst index: World Data Center for Geomagnetism, Kyoto (wdc.kugi.kyoto-u.ac.jp), provisional values via NOAA.
Ejection catalog: NASA CCMC DONKI. Multi-year series for forecast validation: NASA OMNIWeb and SuperMAG (supermag.jhuapl.edu).
SunSonde is not an official warning service. For safety-critical decisions rely on your national space weather service.