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Analysis and modeling of microburst precipitation
Author(s) -
Datta S.,
Skoug R. M.,
McCarthy M. P.,
Parks G. K.
Publication year - 1996
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl01672
Subject(s) - microburst , pitch angle , physics , electron precipitation , spectral line , electron , scattering , range (aeronautics) , computational physics , rocket (weapon) , van allen radiation belt , isotropy , diffusion , atomic physics , magnetosphere , optics , nuclear physics , plasma , geophysics , materials science , meteorology , astronomy , wind speed , wind shear , engineering , composite material , thermodynamics , aerospace engineering
Observations from a recent rocket experiment that measured electrons over the energy range of 1–300 keV shows that microburst temporal structures exist from about 20 keV to >120 keV. Simultaneous observations at five different pitch‐angles (0°–90°) show the distribution is nearly isotropic during the bursts, while at low activity (quiet times and the valleys between microbursts) the distribution is anisotropic with higher fluxes at larger pitch‐angles. The energy spectra were reasonably fit with a Maxwellian, with an e‐folding energy E o ≈6–9 keV for α=0°, which increases to ≈ 10 keV at 67°. A modeling of electron spectra using the theory of pitch‐angle diffusion can reproduce the observed spectra, suggesting pitch‐angle scattering of electrons due to a wave‐particle interaction is the primary mechanism responsible for microbursts.