EUV Observations of the Structure and Dynamics
of the Plasmasphere
Bill R. Sandel, Jerry Goldstein, Dennis Gallagher, & Don Carpenter
The Plan
EUV Measurements
Trough Formation
Plasmasphere Erosion
Bite-Outs (Low Density Regions)
Flux Tube Refilling
The scattering rate or “g-value”:
g = ~1.1 10-4 sec-1
for He+ at 1 AU
S unlight at30.4 nm
Scatte
r ing in a ll directions
The light detected by EUV comes from
Resonant Scattering
Surface Brightness of the Plasmasphere
The surface brightness is a line integral along the line of sight for each pixel:
Mapping image field points to the equatorial plane
To Sun
Earth’s Shadow
Aurora
Imperfect Flat-Fielding Between Cameras
Plasma Tail
Plasmapause Plasmasphere
Extended Plasmasphere
Small Plasmasphere
(Thanks to Mark Moldwin)
Trough Forms by Wrapping a Tail
9 May 2001
2001-129
Plasmasphere Erosion Events 10 July 2000
Distance, Content vs. Time
Plasmasphere Erosion Events 2 June 2001
Bite-Outs in the Plasmasphere
CRRES Results
Carpenter et al., JGR 105, 23,323 (2000)
Green et al., JGR in press
2001-097 & 098
(7 & 8 April)
87% CoR
2000-187 to 189
(5-7 July)
84% CoR
2000-176 to 177
(24-25 June)
98% CoR
Same as inner cavities observed by e.g. CRRES?
CRESS* EUV
Frequency 13% less frequent
Contrast 5-10x 2-4x
Azimuthal Extent up to 20° 10-18°
Inner Boundary L < 3 ~same
LT Distribution < morning ?
*Carpenter et al., JGR, 2000
2000-176
2001-097
Real Modelled
90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
Dst
(nT
)
-120
-100
-80
-60
-40
-20
0
20
40
60
80
180 185 190 195 200 205 210 215 220 225 230 235 240 245 250 255 260 265 270 275
Dst
(nT
)
-120
-100
-80
-60
-40
-20
0
20
40
60
80
Time (Days of 2000)
270 275 280 285 290 295 300 305 310 315 320 325 330 335 340 345 350 355 360 365
Dst
(nT
)
-120
-100
-80
-60
-40
-20
0
20
40
60
80
dst2000.jnb
90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
Dst
(nT
)
-120
-100
-80
-60
-40
-20
0
20
40
60
80
Time (Days of 2001)
180 185 190 195 200 205 210 215 220 225 230 235 240 245 250 255 260 265 270 275
Dst
(nT
)
-120
-100
-80
-60
-40
-20
0
20
40
60
80
90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
Kp
0
2
4
6
8
10
Time (Days of 2001)
180 185 190 195 200 205 210 215 220 225 230 235 240 245 250 255 260 265 270 275
Kp
0
2
4
6
8
10
90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
Kp
0
2
4
6
8
10
Time (Days of 2001)
180 185 190 195 200 205 210 215 220 225 230 235 240 245 250 255 260 265 270 275
Kp
0
2
4
6
8
10
from Wilson et al., Adv. Space Res., 1993.
Flux Tube Refilling--Expectations
Latitude (degrees)
H+ D
en
sity
(cm
-3)
26 August 2000
Isolated Refilling Flux Tube
20 August 2000 08:26 UTC
Model of an Isolated Filled Flux Tube
Range 7.9 RE
Latitude 49 N
?
