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Ann. Geophys., 24, 163-172, 2006
www.ann-geophys.net/24/163/2006/
© European Geosciences Union 2006
A global climatology for equatorial plasma bubbles in the topside ionosphere
L. C. Gentile1, W. J. Burke2, and F. J. Rich2
1Institute for Scientific Research, Boston College, Chestnut Hill, MA, USA
2Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, MA, USA
Abstract. We have developed a global climatology of equatorial
plasma bubble (EPB) occurrence based on evening sector plasma density
measurements from polar-orbiting Defense Meteorological Satellite Program
(DMSP) spacecraft during 1989-2004. EPBs are irregular plasma density
depletions in the post-sunset ionosphere that degrade communication and
navigation signals. More than 14400 EPBs were identified in
~134000 DMSP orbits. DMSP observations basically agree with Tsunoda's (1985)
hypothesis that EPB rates peak when the terminator is aligned with the
Earth's magnetic field, but there are also unpredicted offsets in many
longitude sectors. We present an updated climatology for the full database
from 1989-2004 along with new plots for specific phases of the solar cycle:
maximum 1989-1992 and 1999-2002, minimum 1994-1997, and transition years
1993, 1998, and 2003. As expected, there are significant differences between
the climatologies for solar maximum and minimum and between the two solar
maximum phases as well. We also compare DMSP F12, F14, F15, and F16
observations at slightly different local times during 2000-2004 to examine
local time effects on EPB rates. The global climatologies developed using
the DMSP EPB database provide an environmental context for the long-range
prediction tools under development for the Communication/Navigation Outage
Forecasting System (C/NOFS) mission.
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