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Cold, keV, & MeV ion signatures of westward moving auroral bulge at L=4 in equatorial plane. M. Yamauchi 1 , I. Dandouras 2 , P.W. Daly 3 , H. Frey 4 , P.-A. Lindquvist 5 , G. Stenberg 6 , Y. Ebihara 7 , R. Lundin 1 , H. Nilsson 1 , H. Reme 2 , M. Andre 6 , E. Kronberg 3 , and A. Balogh 8 - PowerPoint PPT Presentation
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Cold, keV, & MeV ion signatures of westward moving auroral
bulge at L=4 in equatorial plane
M. Yamauchi1, I. Dandouras2, P.W. Daly3, H. Frey4, P.-A. Lindquvist5, G. Stenberg6, Y. Ebihara7, R. Lundin1, H. Nilsson1, H. Reme2, M. Andre6, E. Kronberg3, and A. Balogh8
(1) IRF, Kiruna, Sweden, (2) CESR, Toulouse, France, (3) MPS, Katlenburg-Lindau, Germany, (4) UCB/SSL, Berkeley, CA, USA, (5) Alfven Lab., KTH, Stockholm, Sweden, (6) IRF, Uppsala, Sweden, (7) IAR, Nagoya U., Nagoya, Japan, (8) Blackett Lab., ICL, London, UK
ICS-9, Graz, 2008-5 / revised for IMC-workshop, Espoo, 2008-7
25 minH+
O+
H+
He+
0.01~40 keV
102 keV
MeV
Clusterperigee(19 MLT, R≈4 RE, Z=0 RE)
90 minoverview
Z=0 Re, R=4 Re
What do these events indicate?From 06:43 UT event(a) Composition of cold plasma plasmasphere-magnetosphere coupling in the inner magnetosphere.
(b) Mass-dependent filling of medium-energy ring current ions (and by auroral bulge?) drift motion
(c) Propagation of large DC electric field in the equatorial plane.
(d) Inter-SC difference of energetics non-gyrotropic
From 06:48 UT event (not today)(d) Bi-parallel beams in the equatoral plane
(e) Equatorial signature of the transpolar arc.
* Near equator (Z ≈ 0 RE)* Perigee (R ≈ 4 RE)
Spacecraft
SC1-SC4 ≈ 25 sec
SC1-SC3 ≈ 1 min
* 19 MLT
S/C
north
south
dawndusk
sun
tailU
E
IMAGE/FUV 06:26~06:56 UT
06:26 UT
06:28 UT
06:30 UT
06:32 UT
06:34 UTS/C
06:36 UT
06:38 UT
06:40 UT
06:42 UT
06:44 UT
06:46 UT
06:48 UT
06:50
06:52
06:54
06:56
IMAGE/FUV 06:26~06:56 UT
06:26 UT
06:28 UT
06:30 UT
06:32 UT
06:34 UTS/C
06:36 UT
06:38 UT
06:40 UT
06:42 UT
06:44 UT
06:46 UT
06:48 UT
06:50
06:52
06:54
06:56
~06:43 event
IMAGE/FUV 06:26~06:56 UT
06:26 UT
06:28 UT
06:30 UT
06:32 UT
06:34 UTS/C
06:36 UT
06:38 UT
06:40 UT
06:42 UT
06:44 UT
06:46 UT
06:48 UT
06:50
06:52
06:54
06:56
~06:43 event ~06:48 event
Observation of 06:43 UT (#1) event1. Sudden change in particle flux (> 40 keV, > 10 keV,
and < 100 eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
25 minH+
O+
H+
He+
0.01~40 keV
102 keV
MeV
Clusterperigee(19 MLT, R≈4 RE, Z=0 RE)
90 minoverview
Z=0 Re, R=4 Re
keV ions of ionospheric origin?
No mass-energy dispersionBi-directional
= not auroral ions
06:43 UT 06:43 UT
//
//
//
Observation of 06:43 UT (#1) event1. Sudden change in particle flux (> 40 keV, > 10 keV, and < 100
eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
Observation of 06:43 UT (#1) event1. Sudden change in particle flux (> 40 keV, > 10 keV, and < 100
eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
increase in 101~2 keV ion flux
decrease in 102~3 keV ion flux
He < 350 keV
He > 700 keV
O < 0.9 MeV
O > 1.4 MeV
Observation of 06:43 UT (#1) event1. Sudden change in particle flux (> 40 keV, > 10 keV, and < 100
eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
Observation of 06:43 UT (#1) event1. Sudden change in particle flux (> 40 keV, > 10 keV, and < 100
eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
Observation of 06:43 UT (#1) event1. Sudden change in particle flux (> 40 keV, > 10 keV, and < 100
eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
Composition
0643 0644 0645 0646 0647 0648 0649
06:44:00 UT 06:48:30 UT
H+
He++
He+
O+
contamination
(2) TOF mass analyser: He+ rich
No oxygen!
He+ convection ExB velocity
ExB drift velocity = 25~50 km/s4-15 eV for H+
=> 15-60 eV for He+60-250 eV for O+
Detail on Ion dynamics
(spin)Cold ion moving in one (perpendicular) direction
15-60 eV for He+
4-15 eV for H+
Ion drift direction vs E
X (sunward)
Y (duskward)
//
drift direction
- UxB (estimated E) direction
U ≈ -ExB in direction (but no guarantee of frozen-in
Observation Summary (06:43 UT)1. Sudden change in particle flux (>40 keV, >10 keV, and <100
eV) when aurora bulge arrived Cluster’s conjugate ~19 MLT.
2. Change is simultaneous at all SC (SC-3 leading by 1~10 sec).
3. Simultaneous DC field change (tailward E~8mV/m, Pi2-like rarefaction |B|≈|BZ| up to 20%) without special wave activity.
4. Increase in medium energy (~100 keV, mass dependent) ion flux. Diamagnetic effect by ∆PP can quantitatively explain ∆PB.
5. Decrease in energetic e- (>30 keV) and ions (> 0.1 MeV)
6. Temporal (about 1 min) change of pitch-angle of 10-40 keV to more field-aligned than perpendicular.
7. Bulk motion of cold He+ and H+ (no cold O+ or He++). The ion velocity (20km/s, duskward) agrees with the ExB velocity.
Indications (conclusion)E-field propagates together with the auroral bulge
at ground, which is in the same direction as convection direction.
cold He+ flux >> cold O+ flux: plasmaspheric He+ at 4 RE.
No local acceleration: Mass dependent drift ? How did they come on time?
Large-scale configuration change: pseudo-onset?
Energy source? / Can minor auroral activity produce ring current ions?
ion-scale ?All SC should observe the same behavior of ions if ion gyro-radius (RB = mv/qB) >> inter-S/C distance
RB for B ≈ 200 nT condition
10 keV 100 keV 1 MeV
H+ v = 1400 km/s
RB = 70 km
v = 4000 km/s
RB = 200 km
v = 14000 km/s
RB = 700 km
He+ v = 700 km/s
RB = 140 km
v = 2000 km/s
RB = 400 km
v = 7000 km/s
RB = 1400 km
O+ v = 350 km/s
RB = 300 km
v = 1000 km/s
RB = 800 km
v = 3500 km/s
RB = 3000 km
consolation
S/C distance ≈ 100 km in z direction & 50 km in x-y direction
≈ RB for 10~20 keV H+ << RB for Ring current ions
H+ > 20 keV (O+ > 2 keV) should behave the same at all SCs if the gyrotropic assumption is correct
For flux increase: (1) SC-2 < SC-1 < SC4=SC3
H+: 80~160 keVHe+: 200~300 keV
(2) SC-2 > SC-1 > SC4=SC3H+: ~60 keV O+: 500~600 keV
For flux decrease: (3) SC-2 < SC-1 < SC4=SC2
He+: 400~700 keV(4) SC-2 > SC-1 > SC4=SC3
O+: ~400 keV
inter-SC difference !
Hybrid: (5) SC-2 > SC-1 > SC4 > SC3
O+: 400~500 keV
End
Now is the time to analyse/simulate Inter-SC difference of energetic particles with
ion gyro-radius (RB) >> inter-S/C distance
IMAGE/FUV 06:26~06:56 UT
06:26 UT
06:28 UT
06:30 UT
06:32 UT
06:34 UTS/C
06:36 UT
06:38 UT
06:40 UT
06:42 UT
06:44 UT
06:46 UT
06:48 UT
06:50
06:52
06:54
06:56
~06:43 event ~06:48 event
All info
ET
PA
O+ 30~500 eVETPA
ET
PA
25~150 eV
5-25 eV
25~150 eV
5-25 eV
25~150 eV
5-25 eV
25~150 eV
5-25 eV
all at 06:48:30 UT (12s resolution)SC-1: leading
SC-3: 60s behind SC-1
SC-4: 25s behind SC-1
0642 0644 0646 0648 0650 0652 0654 0656
Observation of event #21. Simultaneous at SC-1, 4 and -3 within 1 sec sudden
activation
2. Bi-directional along B, and DC E-field disturbance double parallel potential is carried by convection?
3. Wave with randomly changing Pointing flux direction (not shown here) wave is caused by the bi-parallel beam
4. Decrease 5~70 keV large-scale configuration change
5. More O+ than He+ not from cold plasma
6. Filamentation in the transpolar arc but, the relation is not clear (?)
7. Only minor magnetospheric activity Why do we observed only once in 5 years ?
no wave@06:43 UT, wave@06:48 UT
ion
dE
dB
S//
E/B
dBZ
dBXstagnant
BB-EM
spin effects
150 nT ΩP = 4 Hz
ΩHe?
Composition from energy ratio(1) From energy peak: plasmaspheric He+ rich
= 0°
= 180°
= 360°
10 100 [eV] 10 100 [eV]
Precursor (06:44 UT) Heating (06:49 UT)
H+ He+ O+
ratio=4: O+/He+ or He+/H+
18eV 70eVH+ He+
//
//
SC location* Near equator (Z ≈ 0 RE)* Perigee (R ≈ 4 RE)* 19 MLT* Short distance (mainly in Z direction) SC1-SC4 ≈ 25 sec SC1-SC3 ≈ 1 min
SC
mot
ion
SC
mot
ion
SC motion
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