NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
First Test of Stochastic Growth Theory for Langmuir Waves in Earth's ForeshockThis paper presents the first test of whether stochastic growth theory (SGT) can explain the detailed characteristics of Langmuir-like waves in Earth's foreshock. A period with unusually constant solar wind magnetic field is analyzed. The observed distributions P(logE) of wave fields E for two intervals with relatively constant spacecraft location (DIFF) are shown to agree well with the fundamental prediction of SGT, that P(logE) is Gaussian in log E. This stochastic growth can be accounted for semi-quantitatively in terms of standard foreshock beam parameters and a model developed for interplanetary type III bursts. Averaged over the entire period with large variations in DIFF, the P(logE) distribution is a power-law with index approximately -1; this is interpreted in terms of convolution of intrinsic, spatially varying P(logE) distributions with a probability function describing ISEE's residence time at a given DIFF. Wave data from this interval thus provide good observational evidence that SGT can sometimes explain the clumping, burstiness, persistence, and highly variable fields of the foreshock Langmuir-like waves.
Document ID
19990009117
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Cairns, Iver H.
(Iowa Univ. Iowa City, IA United States)
Robinson, P. A.
(Sydney Univ. Australia)
Date Acquired
August 19, 2013
Publication Date
February 15, 1997
Publication Information
Publication: Geophysical Research Letters
Publisher: American Geophysical Union
Volume: 24
Issue: 4
ISSN: 0094-8534
Subject Category
Geophysics
Report/Patent Number
Paper 97GL00084
Funding Number(s)
CONTRACT_GRANT: NAGw-2040
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available