1

Lecture 30

• Solar Wind: Stix pp. 403-412,

• Knipp, pp. 200-207

Last time…

• How to take limits

• Partial derivatives commute

• Wave trains

• Working with Kronecker deltas

• Chromosphere

• Corona

• Solar Wind

Last time…

Last time…

Last time…

Last time…

Resit homework 2Halpha:

Large-scale

network

Resit homework 2

Resit homework 2

Resit homework 2

2 tails

Resit homework 2

2 tails

• Gas tail ionized

– Follows solar Wind

– Dust tail trails behind

• Mariner II direct evidence for wind

– 400 km/s

• Apollo took samples

• Ulysses: high speed wind: 800 km/s

Resit homework 2

Properties

• Proton temperature 1.5x105 K

• Electron temperature 7.5x105 K

• Speed 400-800 km/s

• Mach number u/cs=10-20

• Alfven Mach number u/vA=5-10

• Magnetic field 5 nT

• Fast wind from coronal holes

Properties

Properties

Resit homework 2

Resit homework 2

20

Non-static corona

Momentum eqn

02 rurdr

d

Continuity eqn

isert

Critical point

2

2 ln

r

GM

dr

dc

dr

duu s

rr

2

222 2ln

r

GM

r

c

dr

udcu sr

sr

21

Logarithmic differentiation

0lnlnln 2

dr

ud

dr

d

dr

rd r

Continuity eqn

Numerical solutions

What we learned today

• Corona: heating and wind acceleration

• Solar Wind

– Smooth transition to supersonic

– Critical point

– Logarithmic differentiation