Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
The Relationship Between the Plasmapause
and Outer Belt Electrons
W.S
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
This Study
• RBSP A and B:
predawn sector, 15-20 Jan 2013
• REPT:
Electron flux > 2 MeV
=> Locations of PEAKS
and EDGES
LPEAK
LEDGE
• EMFISIS: [Goldstein et al., 2014]
Wave-derived electron density (Ne)
=> Plasmapause Location LP
Spatial Relationship Between Plasmasphere and Outer Belt(s)
LP (EMFISIS)
LPEAK
(REPT)
THIS STUDY:
LEDGE
RBSP A only
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Event: 15-20 January 2013
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Automated Extraction: Plasmapause, Outer Belts
• Plasmapause Finder
Peak and
Edge 20
Finder
• •Gradient
crossing
cm-3
dL < 0 and n > 20 cm-3
•dlogn
Peaks:
dlogf dL = 0 and d2 logf dL2 < 0
Connect
• Edges:Local to Global:
exp(-1)
• fpeak
Forf =this
event,
local EMFISIS
measurements good proxy for
global plasmapause.
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Automated Extraction: Plasmapause, Outer Belts
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Comparison: Plasmapause and Outer Belts
• Plasmapause and Outer Belts
Outer belt 1:
Stable zone >3 MeV
1-2 RE inside psphere
Outer belt 2:
Dynamic <3 MeV
within 0.5 RE of moving plasmapause
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
DL Plasmapause and Outer Belts
• Plasmapause and Outer Belts
Outer belt 1:
Stable zone >3 MeV
1-2 RE inside psphere
Outer belt 2:
Dynamic <3 MeV
within 0.5 RE of moving plasmapause
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Interpretation: Pre-Disturbance Outer Belt 1
Outer belt 1:
Decay, hiss
timescales
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Interpretation: Post Disturbance Outer Belt 2
Outer belt 2:
Emptied during disturbance
Restored within 24 hours
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Interpretation: Post Disturbance Outer Belt 1
Outer belt 1:
Partially depleted by disturbance
After: decay on hiss timescales
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Flux versus Energy
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
The Relationship Between the Plasmapause
and Outer Belt Electrons
•
Two outer belts:
1. stable zone (“storage ring”) within cold plasma
2. dynamic zone near plasmapause
•
Outer belt 1:
> 3 MeV, 1-2 RE inside cold plasma
Decaying at hiss time scales before 17 Jan disturbance
After partial dropout, continued to decay at initial rate
•
Outer belt 2:
< 3 MeV, 0.5 RE from plasmapause
Emptied out by disturbance, Restored within 24 hours
High energy electron storage rings can persist for weeks or even months if
prolonged quiet conditions prevail
Jerry Goldstein
SWG Telecon 18 Mar 2016
Plasmapause and Outer Belt Electrons
Local to Global Relationship (Using Model)
Connect Local to Global:
For this event, local EMFISIS measurements
good proxy for global plasmapause.