Does geospace exercise
self control?
Bill Lotko, Dartmouth College
MFLFM Study Group
Oliver Brambles, Peter Damiano, John Lyon, Binzheng Zhang 1
Mike Wiltberger 2
Katie Garcia, Slava Merkin 3
1
2
3
Systems Thinking
The whole is greater than the sum of the parts.
– Aristotle
?
… a framework based on the belief that the
component parts of a system can best be
understood in the context of relationships with each
other and with other systems, rather than in
isolation.
– Wikipedia
A system is what a system is doing. And we had
better not say what a system is.
– Tom Mandel
Systems Thinking
The overall name of these interrelated structures is
system The motorcycle is a system … a system of
system.
concepts worked out in steel. There's no part in it, no
p in it that is not in someone's mind. I've noticed
shape
that people who have never worked with steel have
trouble seeing this – that the motorcycle is primarily
a mental phenomenon.
– Robert Pirsig
Zen and the Art of Motorcycle Maintenance
Systems Thinking
The overall name of these interrelated structures is
system The motorcycle is a system … a system of
system.
concepts worked out in steel. There's no part in it, no
p in it that is not in someone's mind. I've noticed
shape
that people who have never worked with steel have
trouble seeing this – that the motorcycle is primarily
a mental phenomenon.
– Robert Pirsig
Zen and the Art of Motorcycle Maintenance
Systems Thinking
The overall name of these interrelated structures is
system The magnetosphere is a system … a system
system.
of concepts worked out in plasma. There's no part in
p in it that is not in someone's mind. I've
it,, no shape
noticed that people who have never worked with
plasmas have trouble seeing this – that the
magnetosphere is primarily a mental phenomenon.
– Motorcycle-Magnetosphere Equivalency
Zen and the Art of Magnetosphere Maintenance
Systems Thinking
• holistic → integration,
integration synthesis
• framework → relational
• doing → behavioral
• mental → conceptual
Geospace System
≡
Coupled SW,
M
Magnetosphere,
t
h
Ionosphere,
Thermosphere
Limits
• MA, β >> 1 (HD)
–∇P dominant
• MA, β >
~ 1 ((MHD))
j×B dominant
r ds
j = − B ∫ ∇ ⋅ j⊥
B
s
n
LLBL
d Ω ds
j = B∫ ρ
dt B B
s
n
LLBL → MAGNETOSHEATH
r
r
B ⎡ d r
⎤
j⊥ = 2 × ⎢ ρ v + ∇P ⎥
B ⎣ dt
⎦
MAGNETOSPHERE
r
j = −∇ ⋅ J P
MAGNETOSHEATH
r
t r
J P = ∇ ⋅ Σ ⋅ EPC
d r r r
ρ v = j × B − ∇P
dt
IONOSPHERE
MAGNETOPAUSE
r
EPC → Φ PC
r
ERec → Φ Rec
1945 UT
30º Lat
30
20 Nov 2003
Foster et al. 2005
1945 UT
30º Lat
30
20 Nov 2003
Foster et al. 2005
O+ Outflow Flux
Southern Summer 1997-98
(15 eV – 33 keV)
12
O+ ions/m2-s
1012
18
06
1011
1010
109
55°
24
Polar / 7600 km
Lennartsson et al. 2004
Outflow Mechanics
guiding center equations (ε
ambipolar field
centrifugal force
v ⊥ ωc l 1 ωcτ
collisional drag
r
dv
eE
r
r r
=
− μ ∇ B + v E ⋅ Dt b − g ⋅ b − ν c v
dt
m
(ponderomotive)
mirror force
Dt μ = 0
gravity
v ⊥2
where μ =
2B
r
r r
r
r
∂
Dt ≡
+ ( v b + v E ) ⋅ ∇, v E = E × b B
∂t
1)
Causal Relations
1
2
3
Strangeway et al. 2005
Empirical Model for Ionospheric Outflow
FAST data near 4000-km altitude in the low-altitude cusp
Strangeway et al. 05; Zheng et al. 05
Storm-Driven
Outflow
Storm Simulation
MA ≈ 7,, β ≈
1
O+ Outflow Number Flux
North
South
1013 #/m2-s
s
2
1
0
1.06 × 1026 #/s
Fluence
6.41 × 1025 #/s
equatorial plane, SM coordinates
15:50 UT, 31 Aug 2005
AC Poynting Flux
S||ac
12
mW/m2
EM Power In
0.8
O+ Flux Out
0.6
18
06
0.4
0.2
0
Polar / 4-6 RE
24
O+ Up Flux
12
nO+ V||O+
ions/m2-s
1012
Keiling et al. 03
1011
DC Poynting
y
g Flux
S||dc
18
06
12
1010
mW/m2
8.6
109
65
6.5
18
06
4.3
2.2
0
Astrid-2 / 1000 km
24
Olsson et al. 04
Polar / 7600 km
24
Lennartsson et al. 04
r ds
j = − B ∫ ∇ ⋅ j⊥
B
s
n
LLBL
d Ω ds
j = B∫ ρ
dt B B
s
n
LLBL → MAGNETOSHEATH
r
r
B ⎡ d r
⎤
j⊥ = 2 × ⎢ ρ v + ∇P ⎥
B ⎣ dt
⎦
MAGNETOSPHERE
r
j = −∇ ⋅ J P
MAGNETOSHEATH
r
t r
J P = ∇ ⋅ Σ ⋅ EPC
d r r r
ρ v = j × B − ∇P
dt
IONOSPHERE
MAGNETOPAUSE
r
EPC → Φ PC
r
ERec → Φ Rec
Storm-Driven Outflow
No outflow
O+ outflow
Log N
XZ plane, GSE coordinates
Log N
Convection
No outflow
O+ outflow
equatorial plane, SM coordinates
Fractional O+ Pressure
PO/PT
15:50 UT, 31 Aug 2005
1
.8
.6
6
.4
.2
0
6.6 RE
XY plane
SM coordinates
Ring Current
No outflow
O+ outflow
equatorial plane, SM coordinates
r ds
j = − B ∫ ∇ ⋅ j⊥
B
s
n
LLBL
d Ω ds
j = B∫ ρ
dt B B
s
n
LLBL → MAGNETOSHEATH
r
r
B ⎡ d r
⎤
j⊥ = 2 × ⎢ ρ v + ∇P ⎥
B ⎣ dt
⎦
MAGNETOSPHERE
r
j = −∇ ⋅ J P
MAGNETOSHEATH
r
t r
J P = ∇ ⋅ Σ ⋅ EPC
d r r r
ρ v = j × B − ∇P
dt
IONOSPHERE
MAGNETOPAUSE
r
EPC → Φ PC
r
ERec → Φ Rec
Vorticity (Ω||/B)
No outflow
O+ outflow
equatorial plane, SM coordinates
How do J⊥ and J×B in the magnetosheath
change when outflow is added?
Sample
Line
Magnetosheath
g
J⊥, J×B
decrease with outflow
LARGER
– flow diversion away
from stagnation
region is diminished
– more magnetic flux
is reconnected
– reconn. potential,
CPCP are larger
LARGER
r ds
j = − B ∫ ∇ ⋅ j⊥
B
s
n
LLBL
d Ω ds
j = B∫ ρ
dt B B
s
n
LLBL → MAGNETOSHEATH
r
r
B ⎡ d r
⎤
j⊥ = 2 × ⎢ ρ v + ∇P ⎥
B ⎣ dt
⎦
MAGNETOSPHERE
r
j = −∇ ⋅ J P
MAGNETOSHEATH
r
t r
J P = ∇ ⋅ Σ ⋅ EPC
d r r r
ρ v = j × B − ∇P
dt
IONOSPHERE
MAGNETOPAUSE
r
EPC → Φ PC
r
ERec → Φ Rec
J⋅E
No outflow
O+ outflow
equatorial plane, SM coordinates
Dayside
Reconnection
Line
LFM simulation
V = 400 km/s
n = 5 cm-3
Cs = 40 km/s
Bz = -5
5 nT
Σp = 5 mhos
Color-coded density
with streamlines
Lopez et al. 2009
Streamlines in Z = 0.2 RE plane at
±Y = 10,, 5.2,, 4.6,, 4,, 3.7,, 2.9,, and 2.5 RE
Lope
ez et al. 20
009
Comparison of Φrec with ΦPC
V = 400 km/s, n = 5 cm-3, Cs = 40 km/s, Σp = 5 mhos
r ds
j = − B ∫ ∇ ⋅ j⊥
B
s
n
LLBL
d Ω ds
j = B∫ ρ
dt B B
s
n
LLBL → MAGNETOSHEATH
r
r
B ⎡ d r
⎤
j⊥ = 2 × ⎢ ρ v + ∇P ⎥
B ⎣ dt
⎦
MAGNETOSPHERE
r
j = −∇ ⋅ J P
MAGNETOSHEATH
r
t r
J P = ∇ ⋅ Σ ⋅ EPC
d r r r
ρ v = j × B − ∇P
dt
IONOSPHERE
MAGNETOPAUSE
r
EPC → Φ PC
r
ERec → Φ Rec
MI Interaction
With O+ Outflow
– CPCP ↑
– Hemispheric FAC ↓
– Dayside mean conductance ↓
– Precipitating electron power ↓
– Ionospheric Joule diss. ↓
Key Points
• Geospace exercises (some) self control
• Thermosphere-ionosphere
Th
h
i
h
actively
ti l
responds to magnetosphere
• Ionospheric outflows modify
– magnetotail
g
state
– upstream state
– inner
i
magnetosphere
t
h
• Understanding this behavior requires
system thinking
Geospace System Focus Group?
Icebreaker
10:30-12:00 AM today, Erickson Room
“Penetration” electric fields
John Foster
Magnetospheric-ionospheric plasma
circulation Frank Toffoletto
Reconnection and transpolar potentials
Sl
Slava
Merkin
M ki
Global oscillation, periodicity, sawtooth
phenomena Joe Borovsky