Polar cap plasma patch primary linear instability growth rates compared. Issue 4 (9th April 2016)

• Record Type: Journal Article
• Authors: Burston, Robert; Mitchell, Cathryn; Astin, Ivan
• Is Part Of: Journal of geophysical research. Volume 121:Issue 4(2016:Apr.)
• Page Start: 3439
• Page End: 3451
• Publication Date: 2016-04-09
• Subjects: plasma -- patch -- linear -- instability -- growth -- rates; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2015JA021895
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: Four primary plasma instability processes have been proposed in the literature to explain the generation of phase scintillation associated with polar cap plasma patches. These are the gradient drift, current convective, and Kelvin‐Helmholtz instabilities and a small‐scale "turbulence" process. In this paper the range of possible values of the linear growth rates for each of these processes is explored using Dynamics Explorer 2 satellite observations. It is found that the inertial turbulence instability is the dominant process, followed by inertial gradient drift, collisional turbulence, and collisional shortwave current convective instabilities. The other processes, such as Kelvin‐Helmholtz, collisional gradient drift, and inertial shortwave current convective instabilities, very rarely (<1% of the time) give rise to a growth rate exceeding 1/60, that is deemed to be significant (in publications) to give rise to GPS scintillation. Key Points: Growth rates for plasma linear instability processes are investigated Turbulence, gradient drift, and current convective instabilities can all be important Kelvin‐Helmholtz instability is relatively unimportant