{{Short description|Series of intense solar storms in 2003}} {{Use American English|date=March 2021}} {{Use mdy dates|date=March 2021}} {{Infobox solar storm | title = Halloween solar storms, 2003 | image = Aurora dmsp.jpg | alt = | caption = Composite image showing aurorae over northern Europe, taken by DMSP on October 30, 2003 | g-onset = {{Start date|2003|10|df=y}} | g-ended = {{End date|2003|11|df=y}} | g-impacts = Electrical faults and wear to various satellites; satellite communications blackouts; localized power outage in Sweden | solar-cycle = 23 |dst=−383 nT|k-index=9|a-index=204|ar-sxr-flares=X40+|g-scale=5|noaa=10486}}

The '''Halloween solar storms''' were a series of solar storms involving solar flares and coronal mass ejections that occurred from mid-October to early November 2003, peaking around October 28–29.<ref name=USGS2013>{{cite news|title=The Magnetic Storm of Halloween 2003|url=https://www.usgs.gov/blogs/features/usgs_top_story/the-magnetic-storm-of-halloween-2003-2/|accessdate=15 May 2014|newspaper=United States Geological Survey: Science Features|date=15 October 2013}}</ref><ref name=NASA2008>{{cite news|title=NASA - Halloween Storms of 2003 Still the Scariest|url=http://www.nasa.gov/topics/solarsystem/features/halloween_storms.html#.U3TQ_yj9wjI|accessdate=15 May 2014|newspaper=NASA/SOHO|date=27 October 2008}}</ref><ref>{{cite book |last = Balch |first = Christopher |display-authors = et al |title = Service Assessment: Intense Space Weather Storms October 19 – November 07, 2003 |publisher = Department of Commerce |series = NOAA Technical Memorandum |date = 2004 |location = Silver Spring, MD |url = https://www.weather.gov/media/publications/assessments/SWstorms_assessment.pdf}}</ref> This series of storms generated the largest solar flare ever recorded by the GOES system, modeled as strong as X45 (initially estimated at X28 due to saturation of GOES' detectors).<ref>{{cite web|title=2003 Halloween solar storms, sunspot region 2192|url=https://www.spaceweatherlive.com/en/news/view/46/20141028-2003-halloween-solar-storms-sunspot-region-2192|accessdate=9 August 2017|publisher=SpaceWeatherLive.com|date=28 October 2014}}</ref><ref>{{cite web|title=Biggest ever solar flare was even bigger than thought|url=http://www.spaceref.com/news/viewpr.html?pid=13844|accessdate=9 August 2017|publisher=American Geophysical Union|website=SpaceRef.com|date=15 March 2004}}</ref>

==Effects== ===On Earth=== [[File:Winzerla Polarlicht 2003.jpg|thumb|Aurora as seen from Jena, Germany (51°N)]] Satellite-based systems and communications were affected, aircraft were advised to avoid high altitudes near the polar regions,<ref name=NOAA2004>{{cite book|title=NOAA Technical Memorandum OAR SEC-88: HALLOWEEN SPACE WEATHER STORMS OF 2003|date=June 2004|publisher=NOAA Office of Oceanic and Atmospheric Research|location=Boulder, Colorado|url=http://www.swpc.noaa.gov/Services/HalloweenStorms_assessment.pdf|url-status=dead|archiveurl=https://web.archive.org/web/20110728172705/http://www.swpc.noaa.gov/Services/HalloweenStorms_assessment.pdf|archivedate=2011-07-28}}</ref> and a one-hour-long power outage occurred in Sweden as a result of the solar activity.<ref name=NASA2008/> Aurorae were observed at latitudes as far south as Texas<ref name=NASA2008/> and the Mediterranean countries of Europe.<ref name=NOAA2004/> Twelve transformers in South Africa were disabled and had to be replaced, despite the country's low geomagnetic latitude.<ref name=Lloyds-AER-2013-NA-risk>{{cite book |department=Lloyd's of London and Atmospheric and Environmental Research |year=2013 |title=Solar storm risk to the north American electric grid |publisher=Lloyd's of London |url=http://www.lloyds.com/~/media/lloyds/reports/emerging%20risk%20reports/solar%20storm%20risk%20to%20the%20north%20american%20electric%20grid.pdf |access-date=2019-07-31 |archive-date=December 5, 2016 |archive-url=https://web.archive.org/web/20161205115544/http://www.lloyds.com/~/media/lloyds/reports/emerging%20risk%20reports/solar%20storm%20risk%20to%20the%20north%20american%20electric%20grid.pdf |url-status=dead }}</ref>

===On satellites and spacecraft=== The SOHO satellite failed temporarily and the Advanced Composition Explorer (ACE) was damaged by the solar activity.<ref name=NASA2008/> 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.<ref name=NOAA2004/> Astronauts aboard the International Space Station (ISS) had to stay inside the more shielded parts of the Russian Orbital Segment to protect themselves against the increased radiation levels.<ref name=Discover2005>{{cite news|last=Levin|first=Eric|title=2003 Halloween Storms Still Rock Solar System|url=http://discovermagazine.com/2005/jan/halloween-storms-rock-solar-system|accessdate=15 May 2014|newspaper=Discover|date=2 January 2005 |archive-url= https://web.archive.org/web/20170511072828/https://www.discovermagazine.com/2005/jan/halloween-storms-rock-solar-system |archive-date= May 11, 2017 |url-status= dead}}</ref>

Emissions from the CME were later observed by the ''Mars Odyssey'' spacecraft orbiting Mars, ''Ulysses'' spacecraft near Jupiter, and the ''Cassini'' spacecraft en route to Saturn. In April 2004, ''Voyager 2'' was also able to detect them as they reached the spacecraft.<ref name=Discover2005/>

==Analysis== thumb|Various data recorded during the Halloween solar storms One of the solar storms was compared by some scientists in its intensity to the Carrington Event of 1859.<ref>{{cite journal |last = Cid |first = Consuelo |author2=E. Saiz |author3=A. Guerrero |author4=J. Palacios |author5=Y. Cerrato |title = A Carrington-like Geomagnetic Storm Observed in the 21st Century |journal = J. Space Weather Space Clim. |volume = 5 |issue = A16 |pages = A16 |date = 2015 |doi = 10.1051/swsc/2015017 |arxiv = 1505.07028 |bibcode = 2015JSWSC...5A..16C |s2cid = 59019585 }}</ref>

These events occurred during solar cycle 23, approximately three years after its peak in 2000, which was marked by another occurrence of solar activity known as the Bastille Day event.

==See also== * List of solar storms

==References== {{reflist|2}}

{{Solar storms}}

Category:Geomagnetic storms Category:2003 in science Category:2003 natural disasters Solar storm of 2003 Category:October 2003 Category:Meteorological events in 2003