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 Jupiter: Recirculation Process of MeV Electrons 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

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.

Jovian synchrotron radiation

Recirculation Model of Jovian Electrons Nishida, JGR, 81, 1771, 1976

Fujimoto and Nishida, JGR, 95, 3840, 1990

Earth’s magnetosphere

Fujimoto and Nishida, JGR, 95, 4265, 1990

The Russell-McPherron Effect Russell and McPherron, JGR, 78, 92, 1973

Spacecraft charging

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