euv observations of the structure and dynamics of the plasmasphere bill r. sandel, jerry goldstein,...
TRANSCRIPT
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
?
