 Composite image showing aurorae over northern Europe, taken byDMSP on October 30, 2003 | |
| Associated solar active region | |
|---|---|
| NOAA regionno. | 10486 |
| Largest SXR flares | X40+ |
| G5 "Extreme" geomagnetic storm | |
| G-scale (NOAA/SWPC) | |
| Initial onset | October 2003 (2003-10) |
| Dissipated | November 2003 (2003-11) |
| PeakKp-index | 9 |
| PeakAp-index | 204 |
| PeakDst | −383 nT |
| Impacts | Electrical faults and wear to various satellites; satellitecommunications blackouts; localizedpower outage inSweden |
Part ofsolar cycle 23 | |
TheHalloween solar storms were a series ofsolar storms involvingsolar flares andcoronal mass ejections that occurred from mid-October to early November 2003, peaking around October 28–29.[1][2][3] This series of storms generated the largest solar flare ever recorded by theGOES system, modeled as strong as X45 (initially estimated at X28 due to saturation of GOES' detectors).[4][5]
Satellite-based systems and communications were affected, aircraft were advised to avoid high altitudes near thepolar regions,[6] and a one-hour-long power outage occurred inSweden as a result of the solar activity.[2]Aurorae were observed at latitudes as far south asTexas[2] and theMediterranean countries ofEurope.[6] Twelve transformers inSouth Africa were disabled and had to be replaced, despite the country's lowgeomagnetic latitude.[7]
TheSOHO satellite failed temporarily and theAdvanced Composition Explorer (ACE) was damaged by the solar activity.[2] Numerous other spacecraft were damaged or experienced downtime due to various issues. Some of them were intentionally put into safe mode in order to protect sensitive equipment.[6] Astronauts aboard theInternational Space Station (ISS) had to stay inside the more shielded parts of theRussian Orbital Segment to protect themselves against the increased radiation levels.[8]
Emissions from the CME were later observed by theMars Odyssey spacecraft orbitingMars,Ulysses spacecraft nearJupiter, and theCassini spacecraft en route toSaturn. In April 2004,Voyager 2 was also able to detect them as they reached the spacecraft.[8]
One of the solar storms was compared by some scientists in its intensity to theCarrington Event of 1859.[9]
These events occurred duringsolar cycle 23, approximately three years after its peak in 2000, which was marked by another occurrence of solar activity known as theBastille Day event.