Conjugate observation of electron microburst groups by Bremsstrahlung X-ray and riometer techniques

Journal Article · Mon Dec 01 00:00:00 EST 1980 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA085iA12p06760· OSTI ID:6659101

Siren, J C; Rosenberg, T J; Detrick, D; Lanzerotti, L J

The first evidence is reported of simultaneous conjugate electron microburst group precipitation. Groups of bremsstrahlung X ray microbursts (E>25 keV) were observed during a substorm recovery phase by a balloon-borne scintillation counter over Roberval, Quebec, Canada. The microburst groups were accompanied one-to-one by time-delayed and broadened pulses of ionospheric absorption measured by a high sensitivity 30-MHz riometer at Siple Station, Antarctica (Lapprox. =4.1). For the interval of highest correlation, the absolute lag between the two data sets was 4 +- 1 s, to the limit of the relative timing accuracy. Approximately 2 s of the observed lag had been introduces by a low-pass filter in the riometer data acquistion unit. The remainder (2 s) was due to the ionospheric recombination process, which evidently had a response time (tauapprox.5 s) during this event much shorter than that ordinarily associated with the D region of the ionosphere. Model calculations of the ionspheric response to time-varying precipitation, derived from the profile of the measurement X ray flux, provide a consistent picture of simultaneous microburst group precipitation at conjugate points, absolute absorption and the electron spectrum derived from X rays, the degree of variation in absorption and X ray fluxes, and the characteristic ionospheric time constant at the altitude of maximum energy deposition.

• Research Organization: Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742
• OSTI ID: 6659101
• Journal Information: J. Geophys. Res.; (United States), Vol. 85:A12
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTRON PRECIPITATION
GEOMAGNETIC CONJUGACY
MAGNETOSPHERE
BREMSSTRAHLUNG
IONOSPHERE
MAGNETIC BAYS
RIOMETERS
X-RAY DETECTION
CHARGED-PARTICLE PRECIPITATION
DETECTION
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
MEASURING INSTRUMENTS
PLANETARY IONOSPHERES
RADIATION DETECTION
RADIATIONS
640203* - Atmospheric Physics- Magnetospheric Phenomena- (-1987)