CSI 769 Fall 2009 Jie Zhang
Solar and Heliospheric Physics
•Magnetism (corona)•MHD (Magnetohydrodynamics) Physics
•Fluid Physics + Maxwell Equations (EM)•Magnetic Reconnection•Particle Acceleration and Transportation
•Not “Plasma Physics”•Not “Introduction to Space Weather”•Not “Magnetospheric and Ionospheric Physics”
What Physics?
We are located in Milky Way Galaxy
28,000 light yearsfrom the center
One of 200 billionstars in our Galaxy
The Cosmological Context
The Sun: an Ordinary Star
•An ordinary main sequence star
•5 billion years old
•5 billion years more to go
Local Interstellar space
Solar wind creates a big teardrop-shaped heliosphere around the solar system, by interacting with the interstellar wind
Local Interplanetary SpaceThe Earth
3rd planet from the Sun
1 AU = 150 million km
Travel time:By light --8 minutes
By Solar Wind-- ~ 100 hrs
•The Sun is the source of energy for life on Earth
•The Sun (and surrounding heliosphere) is the best lab for studying our universe
•The Sun is the driving source of Space Weather, that has adverse effects on technological system and life on Earth
What Impacts
"Space weather describes the conditions in space that affect Earth and its technological systems. Our space weather is a consequence of the behavior of the sun, the nature of Earth's magnetic field, and our location in the solar system” ----National Academy of Science, 1997
Space Weather
Space Weather: the ProcessSpace Weather: the ProcessSpace Weather: the ProcessSpace Weather: the Process
It starts from an eruption from the Sun.
Prediction depends on how it propagates
Space Weather: effectsSpace Weather: effectsSpace Weather: effectsSpace Weather: effects
Aurora; Geomagnetic Storm
From Space
Space Weather: effectsSpace Weather: effectsSpace Weather: effectsSpace Weather: effects
An adverse effect
Damaged transformer
Power failure due to March 1989 storm
Space Weather: effectsSpace Weather: effectsSpace Weather: effectsSpace Weather: effects
On Human Space Exploration
On crew and passengers of polar-route airplanes
Space Weather: effectsSpace Weather: effectsSpace Weather: effectsSpace Weather: effects
On Satellite Operation
Space Weather: effectsSpace Weather: effectsSpace Weather: effectsSpace Weather: effects
On Communication and Navigation
Space Weather: the SystemsSpace Weather: the SystemsSpace Weather: the SystemsSpace Weather: the Systems
Planet
The Source of the Energy?The Source of the Energy?The Source of the Energy?The Source of the Energy?
Magnetic energy through magnetic field generated by solar dynamo, which has 11-year solar cycle
Solar Cycle(SOHO/MDI)
Planet
Storage of Energy?Storage of Energy?Storage of Energy?Storage of Energy?
Energy stored and released in magnetic field
PFSS Model
TRACE
Planet
Release of Energy: FlaresRelease of Energy: FlaresRelease of Energy: FlaresRelease of Energy: Flares
GOES/SXIRHESSI & TRACE
Planet
Release of Energy and the Release of Energy and the driver?driver?Release of Energy and the Release of Energy and the driver?driver?
Coronal mass ejections
SOHO/LASCO/C2
CME in Interplanetary SpaceCME in Interplanetary Space
STEREO/SECCHI/HI-1
CME Simulation (Credit: Odstrcil)CME Simulation (Credit: Odstrcil)CME Simulation (Credit: Odstrcil)CME Simulation (Credit: Odstrcil)
On Satellite Operation
Planet
Heliosphere: solar windHeliosphere: solar windHeliosphere: solar windHeliosphere: solar wind
Spiral solar wind magnetic field: radial motion of solar wind combined with Sun’s rotation
Sprinkler Analogy
Planet
MagnetosphereMagnetosphereMagnetosphereMagnetosphere
A comet-shaped region around the Earth
Planet
Magnetosphere: SimulationMagnetosphere: SimulationMagnetosphere: SimulationMagnetosphere: Simulation
Planet
MagnetosphereMagnetosphereMagnetosphereMagnetosphere
Electric Currents in Magneto-sphere
Planet
MagnetosphereMagnetosphereMagnetosphereMagnetosphere
Energetic particles in Van Allen radiation belt
Planet
IonosphereIonosphereIonosphereIonosphere
Density fluctuation affects radio wave reflection and transmission
Planet
Neutral Upper AtmosphereNeutral Upper AtmosphereNeutral Upper AtmosphereNeutral Upper Atmosphere
It is coupled with ionosphere
Now, the golden age!
HINODE
Now, the golden age!
STEREO
Now, the golden age!
SDO
Now, the golden age!
•The stunning new observations•More importantly, the mind-opening observations, which provide the instinct insight for scientific understanding
•Advancing in theory•Advancing in computer modeling and computational data processing
•Most importantly, your knowledge of physics principles - what this class cares most!
The Syllabus
Content1. Introduction/Overview: Solar Physics and Space Weather2. MHD Equations including Maxwell Equations3. Solar Magnetism 1: Potential Field, Force Free Field4. Solar Magnetism 2: Helicity, Separators5. Magnetic Reconnection 1: Current Sheet 6. Magnetic Reconnection 2: Magnetic Annihilation7. Magnetic Reconnection 3: Steady Reconnection8. Magnetic Reconnection 4: Unsteady Reconnection 9. Solar Applications: Models of CMEs and Flares10.Solar Applications: Models (student presentation) 11. Heliosphere and Solar Wind12.Shock Formation and Particle Acceleration13. ICMEs and Magnetic Clouds
Text Book• Required:
1. Magnetic Reconnection - MHD Theory and Applications– By Eric Priest and Terry Forbes
• Supplement: 1. Physics of the Solar Corona
• By Markus Aschwanden
2. An Introduction to Plasmas and Particles in the Heliosphere and Magnetosphere– By May-Britt Kallenrode
3. Online Resources
Assignments• Homework
– ~ weekly homework
• Project– Proj 1: PFSS model calculation– Proj 2: pick one from the following two options
• Observing CME/flare Initiation (SDO)• Observing CME Propagation (STEREO)
Grading
• Homework (25%)• Projects (30%)• One mid-term (20%)• One final (25%)
Contact
• Instructors: Prof. Jie Zhang• Contact Info: [email protected] (e-mail)
1-703-993-1998 (phone)• Office Hour: 2:00 PM to 3:30 PM, Thursday
or by appointment• Office: Room 351, Research Bldg 1
The End