Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...
Transcript of Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...
![Page 1: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/1.jpg)
Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things Found In Our Atmosphere Joseph R. Dwyer Department of Physics and Space Science Center, University of New Hampshire
![Page 2: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/2.jpg)
Courtesy Steve Cummer
![Page 3: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/3.jpg)
Sprite as it would appear from across the state of Kansas
moon
Courtesy Steve Cummer
![Page 4: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/4.jpg)
Sprites are high-altitude discharges above thunderstorms
They are caused by powerful lighting flashes near the ground.
![Page 5: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/5.jpg)
They come in various shapes and sizes
Human-Resonance.org
![Page 6: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/6.jpg)
They come in various shapes and sizes
Human-Resonance.org
![Page 7: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/7.jpg)
They come in various shapes and sizes
Human-Resonance.org
![Page 8: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/8.jpg)
They come in various shapes and sizes
Human-Resonance.org
![Page 9: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/9.jpg)
Many of the long filamentary structures seen are actually moving balls of light
McHarg et al. 2010
![Page 10: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/10.jpg)
Streamers • Spites are not like ordinary
lightning, since they do not have hot channels.
• Streamers are propagating
discharge structures. • They carry current electric current
without heating the air very much. • Computer simulations (right)
show us how they work.
![Page 11: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/11.jpg)
The breakdown voltage of air is much lower at high altitudes
• A 12 V battery cannot create an electrical discharge (i.e. a spark) at sea-level pressures.
• That same voltage
would discharge at the pressures where sprites live.
electricalfun.com
![Page 12: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/12.jpg)
The charge motion caused by lightning makes sprites
Grant W. Petty
- - - - -
+++++
The pressures are very low up here and so even
small voltages can make a discharge
• A large positive cloud-to-ground lightning flash can transfer large amounts of positive charge to the ground, leaving negative charge in the cloud.
• The air above the thunderstorm
feels this negative charge, resulting in a voltage in the upper atmosphere.
• Just above the cloud this voltage is
too small to make a discharge. • At about 70 km, the pressure is low
enough so that a streamer discharge forms, making a sprite.
![Page 13: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/13.jpg)
Weird lightning: exhibit A Transient Luminous Events (TLEs)LE
NOAA National Severe Storms Laboratory, adapted from Carlos Miralles (AeroVironment) and Tom Nelson (FMA).
![Page 14: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/14.jpg)
ELVES stands for
Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse
Sources
Rapidly expanding ring of light in the lower ionosphere. Caused by the electromagnetic radiation from lightning near the ground.
![Page 15: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/15.jpg)
Jets
(Gigantic jets, blue jets and blue starters) These are forms of upward lightning.
![Page 16: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/16.jpg)
Pixies, Gnomes and TROLLs (for Transient Red Optical Luminous Lineament)
NOAA National Severe Storms Laboratory, adapted from Carlos Miralles (AeroVironment) and Tom Nelson (FMA).
Pixies and Gnomes
TROLLs
![Page 17: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/17.jpg)
There are other weird thing in our atmosphere: Compact Intracloud Discharges (CIDs)
Photo by Mindi Holcomb
![Page 18: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/18.jpg)
Volcanic Lightning (If the volcano doesn’t get you, the lightning will.)
Source Daily Mail Online
![Page 19: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/19.jpg)
Superbolts (big, bad lightning) 100 times brighter than normal lightning
http://www.erh.noaa.gov/lwx/lightning/va-lightning.htm
![Page 20: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/20.jpg)
Superbolts are similar to lightning on Jupiter (Big Planet = Big Lightning)
Courtesy NASA
![Page 21: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/21.jpg)
Sympathetic lightning
Courtesy NASA
![Page 22: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/22.jpg)
Spider lightning
From http://www.flickr.com
![Page 23: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/23.jpg)
Heat lightning
http://en.wikipedia.org/wiki/Heat_lightning
![Page 24: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/24.jpg)
Bead Lightning As the bright return stroke channel decays, it can break apart into longer lasting beads of light
![Page 25: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/25.jpg)
Ribbon Lightning
Wind blows the subsequent channels sideways
Image via: Disaster Strikes
![Page 26: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/26.jpg)
Rocket-triggered lightning
Credit UF
![Page 27: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/27.jpg)
X-rays from lightning
From Scientific American, May 2005
![Page 28: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/28.jpg)
Thunderstorms glow in gamma-rays.
Dwyer, Smith and Cummer (2012)
DailyGalaxy.com
Gamma-Ray glows recorded by ADELE
NCAR/NSF GV
![Page 29: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/29.jpg)
CGRO/BATSE Terrestrial Gamma-ray Flash (TGF) (Fishman et al. 1994)
http://www.batse.msfc.nasa.gov/batse/tgf/
Explosive production of energetic particles
![Page 30: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/30.jpg)
Terrestrial gamma-ray flash (TGF)
and electron-positron beam seen from space
Courtesy NASA
![Page 31: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/31.jpg)
Courtesy NASA
Terrestrial gamma-ray flash (TGF)
and electron-positron beam seen from space
![Page 32: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/32.jpg)
Global distribution of TGFs seen by RHESSI
Figure from Splitt et al. (2010)
![Page 33: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/33.jpg)
Where do they come from?
http://www.holoscience.com/news/balloon.html http://www.holoscience.com
![Page 34: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/34.jpg)
Where do they come from?
http://www.holoscience.com
1994 – 2005: Here
![Page 35: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/35.jpg)
Where do they come from?
http://www.holoscience.com/news/balloon.html
1994 – 2005: Here
After 2005: Here
http://www.holoscience.com
![Page 36: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/36.jpg)
How do thunderstorms make
terrestrial gamma-ray flashes?
There are two leading models: • Lightning leader emission, similar to x-ray
emission seen near the ground. • Dark Lightning!
![Page 37: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/37.jpg)
Dark Lightning The central avalanche is due to the injection of a single, 1 MeV seed electron. All the other avalanches are produced by x-ray and positron feedback. The top panel is for times, t < 0.5 µs. The middle panel is for t < 2 µs, and the bottom panel is for t < 10 µs.
From Dwyer (2007)
![Page 38: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/38.jpg)
Dark lightning
• A new kind of lightning. • Generates so many high-energy particles that it
discharges the thunderstorm faster than normal lightning.
• Makes currents as big as normal lightning, e.g. > 100,000 amps.
• Emits very little visible light, i.e. appears dark. • Can explain TGFs. • Cosmic rays are not needed.
![Page 39: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/39.jpg)
Multi-pulsed TGFs
From Dwyer (2012)
CGRO/BATSE TGFs
![Page 40: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/40.jpg)
Multi-pulsed TGFs
Dark lightning model result
From Dwyer (2012)
CGRO/BATSE TGFs
![Page 41: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/41.jpg)
Dark Lightning • A new kind of lightning • Among the most powerful discharges on the planet • Invisible to the human eye • Makes TGFs as a by-product
• A radiation hazard for airline passengers and crew • First identified in 2012
The name “dark lightning” was introduced over 100 years ago to describe the Clayden effect, seen in photographs of lightning.
![Page 42: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/42.jpg)
Dark Lightning
August 2012 Scientific American
![Page 43: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/43.jpg)
Radiation doses received by individuals inside aircraft struck by a TGF
From Dwyer et al. (2010)
![Page 44: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/44.jpg)
Wikimedia Commons
And of course ball lightning is very weird.
![Page 45: Sprites, Elves, Trolls, Pixies, Gnomes and Other Strange Things ...](https://reader038.fdocuments.us/reader038/viewer/2022102720/586a14b21a28aba27d8bb884/html5/thumbnails/45.jpg)
Summary
• There are many strange things in our atmosphere that
we are just now learning about. • Who knows what other interesting things we will find
if we just look. • We understand the insides of stars halfway across the
universe better than we understand the insides of thunderstorms 5 miles over our heads.