Editing Tornado (section)

=== Sound and seismology ===
[[File:Tornado infrasound sources.png|thumb|upright=1.2|An illustration of generation of infrasound in tornadoes by the [[Earth System Research Laboratories]]'s Infrasound Program]]
Tornadoes emit widely on the [[acoustics]] [[Audio frequency|spectrum]] and the sounds are caused by multiple mechanisms. Various sounds of tornadoes have been reported, mostly related to familiar sounds for the witness and generally some variation of a whooshing roar. Popularly reported sounds include a freight train, rushing rapids or waterfall, a nearby jet engine, or combinations of these. Many tornadoes are not audible from much distance; the nature of and the propagation distance of the audible sound depends on atmospheric conditions and topography.<ref name="SPC FAQ" />

The winds of the tornado vortex and of constituent turbulent [[eddy (fluid dynamics)|eddies]], as well as airflow interaction with the surface and debris, contribute to the sounds. Funnel clouds also produce sounds. Funnel clouds and small tornadoes are reported as whistling, whining, humming, or the buzzing of innumerable bees or electricity, or more or less harmonic, whereas many tornadoes are reported as a continuous, deep rumbling, or an irregular sound of "noise".<ref name="tornado music">{{cite journal|first=Abdul|last=Abdullah|title=The "Musical" Sound Emitted by a Tornado"|journal=Mon. Wea. Rev.|volume=94|issue=4|pages=213–20|date=April 1966|doi=10.1175/1520-0493(1966)094<0213:TMSEBA>2.3.CO;2|bibcode=1966MWRv...94..213A|url=http://docs.lib.noaa.gov/rescue/mwr/094/mwr-094-04-0213.pdf|url-status=dead|archive-url=https://web.archive.org/web/20170921230829/https://docs.lib.noaa.gov/rescue/mwr/094/mwr-094-04-0213.pdf|archive-date=2017-09-21|citeseerx=10.1.1.395.3099}}</ref>

Since many tornadoes are audible only when very near, sound is not to be thought of as a reliable warning signal for a tornado. Tornadoes are also not the only source of such sounds in severe thunderstorms; any strong, damaging wind, a severe hail volley, or continuous thunder in a thunderstorm may produce a roaring sound.<ref name="sound obs">{{cite journal|first=David K.|last=Hoadley |title=Tornado Sound Experiences |journal=[[Storm Track]] |volume=6 |issue=3 |pages=5–9 |date=1983-03-31 |url=http://www.stormtrack.org/archive/0636.htm |url-status=dead |archive-url=https://web.archive.org/web/20120619210634/http://www.stormtrack.org/archive/0636.htm |archive-date=2012-06-19 }}</ref>

Tornadoes also produce identifiable inaudible [[infrasonic]] signatures.<ref name="tornado infrasonics">{{cite journal|first=A. J.|last=Bedard|title=Low-Frequency Atmospheric Acoustic Energy Associated with Vortices Produced by Thunderstorms|journal=Mon. Wea. Rev.|volume=133|issue=1|pages=241–63|date=January 2005|doi=10.1175/MWR-2851.1|bibcode = 2005MWRv..133..241B |s2cid=1004978|doi-access=free}}</ref>

Unlike audible signatures, tornadic signatures have been isolated; due to the long-distance propagation of low-frequency sound, efforts are ongoing to develop tornado prediction and detection devices with additional value in understanding tornado morphology, dynamics, and creation.<ref name="field programs history"/> Tornadoes also produce a detectable [[seismic]] signature, and research continues on isolating it and understanding the process.<ref name="tornado seismic signal">{{cite journal|first1=Frank|last1=Tatom |first2=Kevin R.|last2=Knupp |first3=Stanley J.|last3=Vitto  |name-list-style=amp |title=Tornado Detection Based on Seismic Signal|journal=J. Appl. Meteorol.|volume=34|issue=2|pages=572–82|doi=10.1175/1520-0450(1995)034<0572:TDBOSS>2.0.CO;2|bibcode = 1995JApMe..34..572T|year=1995 |doi-access=free}}</ref>