ste quiet-time observations during solar minimum
DESCRIPTION
STE quiet-time observations during solar minimum. Linghua Wang, Robert Lin and Janet Luhmann SSL, UC Berkeley. Outline 1. Superthermal electron tail in the quiet-time solar wind 2. Pick-up ions 3. The ion beam traveling radially towards the Sun ??. - PowerPoint PPT PresentationTRANSCRIPT
STE quiet-time observations during solar
minimum
Linghua Wang, Robert Lin and Janet Luhmann
SSL, UC Berkeley
Outline
1. Superthermal electron tail in the quiet-time solar wind
2. Pick-up ions
3. The ion beam traveling radially towards the Sun ??
1. Superthermal electron tail (~2-100 keV)
Sun
R
T
Parker’s spiral B field
D2D1
D0
D31000
0
-1000
1000 0 -1000
GSE Y (RE)
GS
E X
(R
E)
B
A
STE
Earth
2007 May01
19:00 20:00 21:00 22:00 23:00
2007 May 01 (STEREO B )
10-2
10-4
10-1
10-3
10-5
160120
80
4
2
0300
100
500
-50ΘB
Φ
B
|B
|
PA
Flu
x
Flu
x
ST
E D
0
ST
E D
2
D2D1D0D3
2007 May01
STE D0 D1 D2 D3
WIND/3DP EESA-L
WIND/3DP EESA-H
SEPT-E
105
100
10-5
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
Flu
x (c
m2 ·
s ·
sr
· eV
/nu
cleo
n )
-1
100 101 102 103 104 105 106
Energy (eV or eV/nucleon)
STE (STEREO B) +(STEREO B)
2007 May01 (STEREO B)
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-2
10-3
10-4
10-5
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-2.13
~ E-2.07
~ E-1.1
2007 May01 (STEREO B)
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-2
10-3
10-4
10-5
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-2.13
~ E-2.07
~ E-1.1
22:00 23:00 00:00
2007 May 01
STE
D3 D0 D1 D2
4.85 keV
49 keV
1.0
0.6
0.2
60 80 100 120
Pitch angle (degree)
Nor
mal
ized
f
D2D1D0D3
STEREO B 160120
8040
\
160120
8040
160
120
80
40
300
200
100
0
ΦB
P
A
PA
P
A
4.85 keV
49 keV
2007 May01 STEREO A
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-2
10-3
10-4
10-5
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-2.1
~ E-1.94
~ E-1.16
18:00 20:00
2007 May 01
STE
4.18 keV
40 keV 1.0
0.6
0.2
40 60 80 100
Pitch angle (degree)
Nor
mal
ized
f
D2D1D0D3
STEREO A 12080400
\
12080400
150
100
50
0
300
200
100
0
ΦB
P
A
PA
P
A
4.18 keV
40 keV
D2 D1 D0 D3
2007 Jun18 STEREO B
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-1
10-2
10-3
\
10-4
\
10-5\
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-2.1
~ E-1.92
~ E-1.03
2. Pick-up ions
~ E-1.74
2007 Jun18 STEREO B
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-1
10-2
10-3
\
10-4
\
10-5\
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-2.1
~ E-1.92
~ E-1.03
2. Pick-up ions
~ E-1.74
2103
Sun
R
T
D2D1
D0
D3
10:00 12:00 14:00 16:00 18:00
2007 Jun 18 (STEREO B )
150
100
50
0
150
100
50
0
300
200
100
0
ΦB
PA
P
A
D2D1D0D3
4.85keV
10:00 12:00 14:00 16:00 18:00
2007 Jun 18 (STEREO B )
150
100
50
0
150
100
50
0
300
200
100
0
ΦB
PA
P
A
D2D1D0D3
4.85keV
14:00 16:00 18:00
2007 Jun 18 (STEREO A )
150
100
50
0
150
100
50
0
300
200
100
0
ΦB
PA
P
A
D2D1D0D3
5.68keV
14:00 16:00 18:00
2007 Jun 18 (STEREO A )
150
100
50
0
150
100
50
0
300
200
100
0
ΦB
PA
P
A
2103
5.68keV
Sun
R
T
D2D1
D0
D3
Sun
Pick-up ions
SW ions
SC
Sun
Pick-up ions
SW ions
SC
Sun
Pick-up ions
SW ions
D3
Sun
VSW = 500 km/s
690 km/s ~ 10 keV
960 km/s ~ 19 keV in the SW frame
Assume He+
SC
2007 Aug19 STEREO B
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-1
10-2
10-3
\
10-4
\
10-5\
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-1.98
~ E-1.94
~ E-0.95
3. Ion beam traveling radially inward ?
~ E-2.12
D2D1D0D3
2007 Aug19 STEREO B
STE D0 D1 D2 D3
SEPT-E
+
103 104 105 106
Energy (eV)
10-1
10-2
10-3
\
10-4
\
10-5\
10-6
10-7
Flu
x (c
m2 ·
s ·
sr
· eV
)-1
~ E-1.98
~ E-1.94
~ E-0.95
3. Particles traveling radially inward ?
~ E-2.12
2103
Sun
R
T
D2D1
D0
D3
D2D1D0D3
10:00 12:00 14:00 16:00
2007 Aug19 (STEREO B )
120
80
40
0\\
120
80
40
0
300
200
100
0
ΦB
PA
P
A
D2D1D0D3
4.85keV
10:00 12:00 14:00 16:00
2007 Aug19 (STEREO B )
120
80
40
0\\
120
80
40
0
300
200
100
0
ΦB
PA
P
A
D2D1D0D3
4.85keV
D3
Sun
VSW = 350 km/s
690 km/s ~ 10 keV in the SC frame
870 km/s ~ 16 keV in the SW frame
Assume He ions
~18 keV
D0~21 keV
~22 keV D1
D2
Conclusions
1. Superthermal electron tail (~2-20 keV) in the solar wind during solar minimum:
Power law, ~ -2; isotropic
2. Pick-up ions , ~ 20 keV (if He+) in the solar wind frame
3. Ion beam traveling radially towards the Sun ??
+STE D0 D1 D2 D3
102
101
100
\
10-1
\ 103 104 105
Energy (eV)
Cou
nts
/s