{{Short description|Lightning produced by a volcanic eruption}} {{Infobox weather type |name= Volcanic lightning |image= Taal Lightning Strike During Eruption (retouched).jpg |caption= Volcanic lightning during the January 2020 eruption of Taal Volcano |sign=Associated with volcanic eruptions |type=Thunderstorm |cloud=Ash |effect=Lightning }} {{Weather}} '''Volcanic lightning''' is an electrical discharge caused by a volcanic eruption rather than from an ordinary thunderstorm. Volcanic lightning arises from colliding and fragmenting particles of volcanic ash (and sometimes ice),<ref>{{Cite news|url=https://www.washingtonpost.com/news/capital-weather-gang/wp/2016/04/13/scientists-think-theyve-solved-the-mystery-of-how-volcanic-lightning-forms/|title=Scientists think they've solved the mystery of how volcanic lightning forms|last=Fritz|first=Angela|date=2016|newspaper=The Washington Post}}</ref><ref>{{Cite news|url=https://www.seeker.com/mystery-of-volcano-lightning-explained-1771209774.html|title=Mystery of Volcano Lightning Explained|last=Mulvaney|first=Kieran|date=2016|work=Seeker}}</ref> which generate static electricity within the volcanic plume,<ref>{{Cite news|url=https://blogs.agu.org/geospace/2016/04/12/new-studies-uncover-mysterious-processes-generate-volcanic-lightning/|title=New studies uncover mysterious processes that generate volcanic lightning|last=Lipuma|first=Lauren|date=2016|work=American Geophysical Union GeoSpace Blog}}</ref> leading to the name '''dirty thunderstorm'''.<ref>{{Cite journal|last=Hoblitt|first=Richard P.|date=2000|title=Was the 18 May 1980 lateral blast at Mt St Helens the product of two explosions?|journal=Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences|volume=358|issue=1770|pages=1639–1661|bibcode=2000RSPTA.358.1639H|doi=10.1098/rsta.2000.0608|s2cid=92549298 |doi-access=}}</ref><ref name=":6">{{Cite journal|last1=Bennett|first1=A J|last2=Odams|first2=P|last3=Edwards|first3=D|last4=Arason|first4=Þ|date=2010-10-01|title=Monitoring of lightning from the April–May 2010 Eyjafjallajökull volcanic eruption using a very low frequency lightning location network|journal=Environmental Research Letters|volume=5|issue=4|article-number=044013|bibcode=2010ERL.....5d4013B|doi=10.1088/1748-9326/5/4/044013|issn=1748-9326|doi-access=free}}</ref> Moist convection currents and ice formation also drive the eruption plume dynamics<ref name=":7">{{Cite journal|last=Woods|first=Andrew W.|date=1993|title=Moist convection and the injection of volcanic ash into the atmosphere |journal=Journal of Geophysical Research: Solid Earth|volume=98|issue=B10|pages=17627–17636|doi=10.1029/93JB00718|bibcode=1993JGR....9817627W}}</ref><ref name=":8">{{Cite journal|last1=Van Eaton|first1=Alexa R.|last2=Mastin|first2=Larry G.|last3=Herzog|first3=Michael|last4=Schwaiger|first4=Hans F.|last5=Schneider|first5=David J.|last6=Wallace|first6=Kristi L.|last7=Clarke|first7=Amanda B.|date=2015-08-03|title=Hail formation triggers rapid ash aggregation in volcanic plumes |journal=Nature Communications|volume=6|issue=1|page=7860|doi=10.1038/ncomms8860 |pmid=26235052|pmc=4532834|doi-access=free |issn=2041-1723|bibcode=2015NatCo...6.7860V}}</ref> and can trigger volcanic lightning.<ref>{{Cite journal|last1=Williams|first1=Earl R.|last2=McNutt|first2=Stephen R.|date=2005|title=Total water contents in volcanic eruption clouds and implications for electrification and lightning|url=http://www.giseis.alaska.edu/Input/steve/PUBS/williams-mcn-signpost.PDF|journal=Proceedings of the 2nd International Conference on Volcanic Ash and Aviation Safety|pages=67–71|archive-date=2019-02-24|access-date=2019-02-24|archive-url=https://web.archive.org/web/20190224173548/http://www.giseis.alaska.edu/Input/steve/PUBS/williams-mcn-signpost.PDF}}</ref><ref name=":9">{{Cite journal|last1=Van Eaton|first1=Alexa R.|last2=Amigo|first2=Álvaro|last3=Bertin|first3=Daniel|last4=Mastin|first4=Larry G.|last5=Giacosa|first5=Raúl E.|last6=González|first6=Jerónimo|last7=Valderrama|first7=Oscar|last8=Fontijn|first8=Karen|last9=Behnke|first9=Sonja A.|date=2016-04-12|title=Volcanic lightning and plume behavior reveal evolving hazards during the April 2015 eruption of Calbuco volcano, Chile |journal=Geophysical Research Letters|volume=43|issue=7|pages=3563–3571|doi=10.1002/2016gl068076 |doi-access=free |issn=0094-8276|bibcode=2016GeoRL..43.3563V|hdl=10533/238214|hdl-access=free}}</ref> Unlike ordinary thunderstorms, volcanic lightning can also occur when there are no ice crystals in the ash cloud.<ref>{{Cite journal|last1=Cimarelli|first1=C.|last2=Alatorre-Ibargüengoitia|first2=M.A.|last3=Kueppers|first3=U.|last4=Scheu|first4=B.|last5=Dingwell|first5=D.B.|date=2014|title=Experimental generation of volcanic lightning |journal=Geology|volume=42|issue=1|pages=79–82|doi=10.1130/g34802.1 |doi-access=free |issn=1943-2682|bibcode=2014Geo....42...79C}}</ref><ref>{{Cite journal|last1=Cimarelli|first1=C.|last2=Alatorre-Ibargüengoitia|first2=M. A.|last3=Aizawa|first3=K.|last4=Yokoo|first4=A.|last5=Díaz-Marina|first5=A.|last6=Iguchi|first6=M.|last7=Dingwell|first7=D. B.|date=2016-05-06|title=Multiparametric observation of volcanic lightning: Sakurajima Volcano, Japan |journal=Geophysical Research Letters|volume=43|issue=9|pages=4221–4228|doi=10.1002/2015gl067445 |doi-access=free |issn=0094-8276|bibcode=2016GeoRL..43.4221C}}</ref>
The earliest recorded observations of volcanic lightning<ref name=":4">{{cite journal|last1=Mather|first1=T. A.|last2=Harrison|first2=R. G.|date=July 2006|title=Electrification of volcanic plumes|journal=Surveys in Geophysics|volume=27|issue=4|pages=387–432|doi=10.1007/s10712-006-9007-2|issn=0169-3298|bibcode=2006SGeo...27..387M|s2cid=53140261 }}</ref> are from Pliny the Younger, describing the eruption of Mount Vesuvius in AD 79, "There was a most intense darkness rendered more appalling by the fitful gleam of torches at intervals obscured by the transient blaze of lightning."<ref name="volcano.oregonstate.edu">{{cite web|url=http://volcano.oregonstate.edu/history-volcanic-lightning|title=History of Volcanic Lightning {{!}} Volcano World {{!}} Oregon State University|website=volcano.oregonstate.edu|date=27 May 2010 |access-date=2018-05-09}}</ref> The first studies of volcanic lightning were also conducted at Mount Vesuvius by Luigi Palmieri<ref>{{cite web |last1=Perrone |first1=Alessio |title=A Defiant Volcanologist Survived 5 Eruptions while Living on Mount Vesuvius |url=https://www.scientificamerican.com/article/a-defiant-volcanologist-survived-5-eruptions-while-living-on-mount-vesuvius/ |website=Scientific American |publisher=Springer Nature |access-date=19 April 2024 |language=en}}</ref> who observed the eruptions of 1858, 1861, 1868, and 1872 from the Vesuvius Observatory. These eruptions often included lightning activity.<ref name="volcano.oregonstate.edu"/>
Instances of volcanic lightning have also been reported above Alaska's Mount Augustine volcano,<ref name="Handwerk">{{cite web|url=http://news.nationalgeographic.com/news/2007/02/070222-volcano-lightning.html|archive-url=https://web.archive.org/web/20070225100233/http://news.nationalgeographic.com/news/2007/02/070222-volcano-lightning.html|archive-date=February 25, 2007|title=Volcanic Lightning Sparked by "Dirty Thunderstorms"|last=Handwerk|first=Brian|date=February 22, 2007|publisher=National Geographic|access-date=2009-01-09}}</ref> Iceland's Eyjafjallajökull and Grimsvötn,<ref>{{cite web|url=http://news.nationalgeographic.com/news/2010/04/photogalleries/100419-iceland-volcano-lightning-ash-pictures/|archive-url=https://web.archive.org/web/20100421081030/http://news.nationalgeographic.com/news/2010/04/photogalleries/100419-iceland-volcano-lightning-ash-pictures/|archive-date=April 21, 2010|title=Iceland Volcano Pictures: Lightning Adds Flash to Ash|date=April 19, 2010|publisher=National Geographic|access-date=2010-04-20}}</ref> Mount Etna in Sicily, Italy,<ref>{{cite web|title = Sky lights up over Sicily as Mount Etna's Voragine crater erupts|url = https://www.theguardian.com/world/2015/dec/03/sicily-mount-etna-voragine-crater-erupts-lightning|website = The Guardian|access-date = 2015-12-03|first = Ian |last = Sample| date=3 December 2015 }}</ref> Taal Volcano in the Philippines,<ref>{{cite news |last1=Borbon |first1=Christian |title=Philippines: Volcano near Manila spews giant ash column |url=https://gulfnews.com/photos/news/philippines-volcano-near-manila-spews-giant-ash-column-1.1578821858529 |access-date=12 January 2020 |publisher=Gulf News}}</ref> Mount Ruang in Indonesia,<ref>{{cite news |title=Gunung Ruang Kembali Erupsi, Warga Diimbau Mengungsi|url=https://www.cnnindonesia.com/nasional/20240417205442-24-1087445/video-gunung-ruang-kembali-erupsi-warga-diimbau-mengungsi|access-date=17 April 2024 |publisher=CNN Indonesia}}</ref> and Volcán de Fuego in Guatemala.<ref>{{cite news|url=https://www.smithsonianmag.com/smart-news/lightning-dazzles-onlookers-watching-the-eruption-of-volcan-de-fuego-in-guatemala-180984367/|title=Lightning Dazzles Onlookers Watching the Eruption of Volcán de Fuego in Guatemala|first=Sarah|last=Kuta|publisher=Smithsonian Magazine|date=15 May 2024}}</ref>
==Charging mechanisms==
=== Ice charging === [[File:Rinjani 1994.jpg |thumb|1994 eruption of Mount Rinjani]] Ice charging is thought to play an important role in certain types of eruption plumes{{mdash}}particularly those rising above the freezing level or involving magma-water interaction.<ref name=":10">{{Cite journal|last1=Arason|first1=Pordur|last2=Bennett|first2=Alec J.|last3=Burgin|first3=Laura E.|date=2011|title=Charge mechanism of volcanic lightning revealed during the 2010 eruption of Eyjafjallajökull |journal=Journal of Geophysical Research|volume=116 |issue=B12|pages=B00C03|doi=10.1029/2011jb008651 |doi-access=free |issn=0148-0227|bibcode=2011JGRB..116.0C03A}}</ref> Ordinary thunderstorms produce lightning through ice charging<ref>{{Cite journal|last=Saunders|first=C.P.R.|date=1993|title=A Review of Thunderstorm Electrification Processes |journal=Journal of Applied Meteorology|volume=32|issue=4|pages=642–65 |doi=10.1175/1520-0450(1993)032<0642:AROTEP>2.0.CO;2 |doi-access=free|bibcode=1993JApMe..32..642S}}</ref> as water clouds become electrified from colliding ice crystals and other hydrometeors.<ref>{{Cite journal|last1=Deierling|first1=Wiebke|last2=Petersen|first2=Walter A.|last3=Latham|first3=John|last4=Ellis|first4=Scott|last5=Christian|first5=Hugh J.|date=2008-08-15|title=The relationship between lightning activity and ice fluxes in thunderstorms |journal=Journal of Geophysical Research|volume=113|issue=D15|pages=D15210|doi=10.1029/2007jd009700 |doi-access=free |issn=0148-0227|bibcode=2008JGRD..11315210D}}</ref> Volcanic plumes can also carry abundant water.<ref>{{cite journal|last1=Glaze|first1=Lori S.|last2=Baloga|first2=Stephen M.|last3=Wilson|first3=Lionel|date=1997-03-01|title=Transport of atmospheric water vapor by volcanic eruption columns|journal=Journal of Geophysical Research: Atmospheres|volume=102|issue=D5|pages=6099–6108|bibcode=1997JGR...102.6099G|doi=10.1029/96jd03125 |doi-access=free |issn=0148-0227}}</ref> This water is sourced from the magma,<ref>{{Citation|last1=Cashman|first1=Katharine V.|title=Magmatic Fragmentation|date=2015 |encyclopedia=The Encyclopedia of Volcanoes|pages=459–471|publisher=Elsevier|isbn=978-0-12-385938-9 |doi=10.1016/b978-0-12-385938-9.00025-0 |last2=Scheu|first2=Bettina}}</ref> vaporized from surrounding sources such as lakes and glaciers,<ref>{{Citation|last1=Houghton|first1=Bruce|title=Phreatomagmatic and Related Eruption Styles|date=2015 |encyclopedia=The Encyclopedia of Volcanoes |pages=537–552|publisher=Elsevier|isbn=978-0-12-385938-9 |doi=10.1016/B978-0-12-385938-9.00030-4 |last2=White|first2=James D.L.|last3=Van Eaton|first3=Alexa R.}}</ref> and entrained from ambient air as the plume rises through the atmosphere.<ref name=":7" /> One study suggested that the water content of volcanic plumes can be greater than that of thunderstorms.<ref>{{Cite journal|last1=McNutt|first1=Stephen R.|last2=Williams|first2=Earle R.|date=2010-08-05|title=Volcanic lightning: global observations and constraints on source mechanisms|url=https://www.researchgate.net/publication/225173821|journal=Bulletin of Volcanology|volume=72|issue=10|pages=1153–1167|doi=10.1007/s00445-010-0393-4|issn=0258-8900 |via=Research Gate|bibcode=2010BVol...72.1153M|s2cid=59522391 }}</ref> The water is initially transported as a hot vapor, which condenses to liquid in the rising column and ultimately freezes to ice if the plume cools well below freezing.<ref>{{Cite journal|last1=Durant|first1=A. J.|last2=Shaw|first2=R. A.|last3=Rose|first3=W. I.|last4=Mi|first4=Y.|last5=Ernst|first5=G. G. J.|date=2008-05-15|title=Ice nucleation and overseeding of ice in volcanic clouds |journal=Journal of Geophysical Research|volume=113|issue=D9|pages=D09206|doi=10.1029/2007jd009064 |doi-access=free |issn=0148-0227|bibcode=2008JGRD..113.9206D|url=https://digitalcommons.mtu.edu/cgi/viewcontent.cgi?article=1030&context=geo-fp|url-access=subscription}}</ref> Some eruptions even produce volcanic hail.<ref name=":8" /><ref>{{Cite journal|last1=Arason|first1=Þórdur|last2=Þorláksdóttir|first2=S.B. |display-authors=etal |date=2013|title=Properties of ash-infused hail during the Grímsvötn 2011 eruption and implications for radar detection of volcanic columns|url=http://hergilsey.is/arason/rit/2013/arason_et_al_2013_egu_hagl_e.pdf|journal=Geophysical Research Abstracts|volume=15|pages=EGU2013–EGU4797|bibcode=2013EGUGA..15.4797A}}</ref> Support for the ice-charging hypothesis includes the observation that lightning activity greatly increases once volcanic plumes rise above the freezing level,<ref name=":0">{{cite journal|last=McNutt|first=S. R.|date=June 2, 2008|title=Volcanic lightning: global observations and constraints on source mechanisms|url=https://www.researchgate.net/publication/225173821|journal=Bulletin of Volcanology|volume=72|issue=10|pages=1153–1167|via=Research Gate|bibcode=2010BVol...72.1153M|doi=10.1007/s00445-010-0393-4|s2cid=59522391 }}{{clarify|reason=citation date (2008) does not match date at url (December 2010);|date=February 2019}}</ref><ref name=":10" /> and evidence that ice crystals in the anvil top of the volcanic cloud are effective charge-carriers.<ref name=":9" />
=== Frictional charging === Triboelectric (frictional) charging within the plume of a volcano during eruption is thought to be a major electrical charging mechanism. Electrical charges are generated when rock fragments, ash, and ice particles in a volcanic plume collide and produce static charges, similar to the way that ice particles collide in regular thunderstorms.<ref name=":4" /> The convective activity causing the plume to rise then separates the different charge regions, ultimately causing electrical breakdown.
=== Fractoemission === Fractoemission is the generation of charge through break-up of rock particles. It may be a significant source of charge near the erupting vent.<ref>{{cite journal|last1=James|first1=M. R.|last2=Lane|first2=S. J.|last3=Gilbert|first3=J. S.|date=2000|title=Volcanic plume electrification: Experimental investigation of a fracture-charging mechanism|journal=Journal of Geophysical Research: Solid Earth|volume=105|issue=B7|pages=16641–16649|doi=10.1029/2000JB900068|issn=2156-2202|bibcode=2000JGR...10516641J|doi-access=free}}</ref>
=== Radioactive charging === Although it is thought to have a small effect on the overall charging of volcanic plumes, naturally occurring radioisotopes within ejected rock particles may nevertheless influence particle charging.<ref name=":2">{{cite web|url=http://www.electrostatics.org/images/ESA_2014_G_Aplin_et_al.pdf|title=Electronic Charging of Volcanic Ash|last=Alpin|first=Karen|display-authors=etal|date=2014|website=Electrostatics.org|access-date=May 8, 2018|archive-date=May 6, 2021|archive-url=https://web.archive.org/web/20210506195919/http://www.electrostatics.org/images/ESA_2014_G_Aplin_et_al.pdf}}</ref> In a study performed on ash particles from the Eyjafjallajökull and Grímsvötn eruptions, scientists found that both samples possessed a natural radioactivity above the background level, but that radioisotopes were an unlikely source of self-charging in the Eyjafjallajökull plume.<ref name=":5">{{Citation|last1=Aplin|first1=K.L.|title=Electrostatics and In Situ Sampling of Volcanic Plumes|date=2016|work=Volcanic Ash|pages=99–113|publisher=Elsevier|isbn=978-0-08-100405-0|last2=Bennett|first2=A.J.|last3=Harrison|first3=R.G.|last4=Houghton|first4=I.M.P.|doi=10.1016/b978-0-08-100405-0.00010-0}}</ref> However, there was the potential for greater charging near the vent where the particle size is larger.<ref name=":2" /> Research continues, and the electrification via radioisotopes, such as radon, may in some instances be significant and at various magnitudes a somewhat common mechanism.<ref name="Nicoll">{{cite journal |last = Nicoll |first = Keri |author2 = M. Airey |author3 = C. Cimarelli |author4 = A. Bennett |author5 = G. Harrison |author6 = D. Gaudin |author7 = K. Aplin |author8 = K. L. Koh |author9 = M. Knuever |author10 = G. Marlton |title = First In Situ Observations of Gaseous Volcanic Plume Electrification |journal = Geophys. Res. Lett. |volume = 46 |issue = 6|pages = 3532–3539|date = 2019 |doi = 10.1029/2019GL082211 |bibcode = 2019GeoRL..46.3532N |url = https://research-information.bristol.ac.uk/files/196236580/Full_text_PDF_final_published_version_.pdf |doi-access = free }}</ref>
=== Plume height === The height of the ash plume appears to be linked with the mechanism which generates the lightning. In taller ash plumes (7–12 km) large concentrations of water vapor may contribute to lightning activity, while smaller ash plumes (1–4 km) appear to gain more of their electric charge from fragmentation of rocks near the vent of the volcano (fractoemission).<ref name=":0" /> The atmospheric temperature also plays a role in the formation of lightning. Colder ambient temperatures promote freezing and ice charging inside the plume, thus leading to more electrical activity.<ref>{{cite journal|last1=Bennett|first1=A. J.|last2=Odams|first2=P.|last3=Edwards|first3=D.|last4=Arason|first4=Þ.|date=2010|title=Monitoring of lightning from the April–May 2010 Eyjafjallajökull volcanic eruption using a very low frequency lightning location network|journal=Environmental Research Letters|volume=5|issue=4|article-number=044013|doi=10.1088/1748-9326/5/4/044013|bibcode=2010ERL.....5d4013B|doi-access=free}}</ref><ref name=":5" />
== Lightning-induced volcanic spherules == Experimental studies and investigation of volcanic deposits have shown that volcanic lighting creates a by-product known as "lightning-induced volcanic spherules" (LIVS).<ref name=":3">{{cite journal|last1=Genareau|first1=Kimberly|last2=Wardman|first2=John B.|last3=Wilson|first3=Thomas M.|last4=McNutt|first4=Stephen R.|last5=Izbekov|first5=Pavel|date=2015|title=Lightning-induced volcanic spherules|journal=Geology|volume=43|issue=4|pages=319–322|doi=10.1130/G36255.1|issn=1943-2682|bibcode=2015Geo....43..319G|doi-access=free}}</ref><ref name=":1">{{cite web|url=https://www.science.org/content/article/flash-glass-lightning-inside-volcanic-ash-plumes-create-glassy-spherules|title=Flash glass: Lightning inside volcanic ash plumes create glassy spherules|last=Perkins|first=Sid|date=March 4, 2015|publisher=American Association for the Advancement of Science}}</ref> These tiny glass spherules form during high-temperatures processes such as cloud-to-ground lightning strikes, analogous to fulgurites.<ref name=":3" /> The temperature of a bolt of lightning can reach 30,000 °C. When this bolt contacts ash particles within the plume it may do one of two things: (1) completely vaporize the ash particles,<ref>{{Cite journal|last1=Genareau|first1=K.|last2=Gharghabi|first2=P.|last3=Gafford|first3=J.|last4=Mazzola|first4=M.|date=2017|title=The Elusive Evidence of Volcanic Lightning|journal=Scientific Reports|volume=7|issue=1|page=15508|doi=10.1038/s41598-017-15643-8|pmid=29138444|pmc=5686202|issn=2045-2322|bibcode=2017NatSR...715508G}}</ref> or (2) cause them to melt and then quickly solidify as they cool, forming orb shapes.<ref name=":1" /> The presence of lightning-induced volcanic spherules may provide geological evidence for volcanic lightning when the lightning itself was not observed directly.<ref name=":3" />
==References== {{reflist|33em}}
==External links== *{{commons-inline}}
Category:Severe weather and convection Category:Lightning Category:Electrical phenomena Category:Volcanic eruptions