investigations on atmospheric acceleration of energetic electrons by erg and scope
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Investigations on Atmospheric Acceleration of Energetic Electrons by ERG and SCOPE. Wing-Huen Ip Institutes of Space Science and Astronomy National Central University March 17, 2009. Outline. TGFs TLEs Saturn: Extreme Electrostatic Charging - PowerPoint PPT PresentationTRANSCRIPT
Investigations on Atmospheric Acceleration of Energetic
Electrons by ERG and SCOPE
Wing-Huen IpInstitutes of Space Science and Astron
omyNational Central University
March 17, 2009
Outline
• TGFs• TLEs• Saturn: Extreme Electrostatic Charging • Jupiter: Recirculation Process of MeV Elec
trons • Earth: The Russel-McPherron Effect• Space Weather
Terrestrial Gamma-ray Flashes (TGFs)
Terrestrail Gamma-ray Flashes:CGRO-BATSE Observations
• NASA Compton Gamma-ray Observatory (CGRO) BATSE detected atmospheric gamma-ray bursts at 10’s MeV (Fishman et al. 1994)
• Close association with thunderstorm and lightning activity (Inan et al., 1996)
• Events lasted for a few mseconds to few tens of mseconds
Fishman et al., Science, 264, 1313, 1994
RHESSI observations of TGFs
• RHESSI showed seasonal and geographic correlation of TGFs with lightning hot spots (Smith et al., 2005)
Smith et al., Science, 307, 1085, 2005
• ~17% of TGFs detected by CGRO/BATSE have been reclassified to be 30 MeV electrons/positrons (Dwyer et al., 2008)
Smith et al., Science, 307, 1085, 2005
Theory
• Relativistic runaway electron beams driven upward by intense QE field following positive cloud-to-ground discharges (Gurevich et al., Phys. Lett., A, 165, 463, 1992)
• DC electric field ~ potential drop of about 30 MV (Tonev and Velinov, Adv. Space Res., 31, 1443, 2003)
Transient Luminous Events(LTEs)
First color image of a sprite
http://sprite.phys.ncku.edu.tw/new/news/0626_presss/big_red_sprites_sentman_s.jpg
Valdivia et al., GRL, 24, 3169, 1997
Trapped relativistic electrons from lightning
Lehtinen et al., GRL, 27, 1095, 2000
Saturnian rings
Formation of radial spokes
Jones, et al. GRL, 33, L21202, 2006.
Jones, et al. GRL, 33, L21202, 2006.
Jovian synchrotron radiation
http://www.atmos.ucla.edu/~bhattach/sr.gif
Recirculation Model of Jovian Electrons
Nishida, JGR, 81, 1771, 1976
Fujimoto and Nishida, JGR, 95, 3840, 1990
Earth’s magnetosphere
http://farm4.static.flickr.com/3097/3128294877_2558320fbc.jpg
Fujimoto and Nishida, JGR, 95, 4265, 1990
The Russell-McPherron Effect
Russell and McPherron, JGR, 78, 92, 1973
Spacecraft charging
http://sd-www.jhuapl.edu/UPOS/SCA/spacecraft-charging-assessment-final-report.pdf
Thanks