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The 3D Space Environment Possible topics to be covered. Outline of Concepts. What is the space environment, what is space weather? How does space compare with Earth’s atmospheric environment and weather? What fills space, how does it get there? How does the Sun affect the Earth?
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Outline of Concepts • What is the space environment, what is space weather? • How does space compare with Earth’s atmospheric environment and weather? • What fills space, how does it get there? • How does the Sun affect the Earth? • What other systems are affected by what’s going on in space?
What is the space environment • Space is not an empty vacuum; there are atoms in space, the building blocks of all matter. • In a cubic centimeter in space there are 5 atoms. • In air on Earth there are billions and billions and billions of atoms in a single cubic centimeter. • The atoms in space come from the atmosphere of the Sun. • The atoms move away from the Sun in a stream called the solar wind. • The atoms make up the solar wind plasma
The Sun • The Sun is 4.6 billion years old! • More than 1 million Earths are needed to fill a ball the size of Sun. • The Sun has a wind that blows at 1 million miles/hr • The Sun is very very hot (millions of degrees F). • The solar wind carries away 1 million tons of material per second--but the Sun will still last at least 4.5 million years beyond today. • The Sun has a very strong magnetic field that reaches out to the edge of the solar system.
The Sun-Earth System: The Earth • The Earth is 4.5 billion years old. • It is the third planet from the Sun, orbiting the Sun once each year. • The distance from center to surface is nearly 4,000 miles (e.g. Detroit to Paris, France) • It has a magnetic field generated in the molten core Images courtesy NASA, spacespin.org
Courtesy Britannica.com Courtesy bbc.co.uk Courtesy physics.gla.ac.uk Magnetic Fields • Types of Magnets • Electromagnets -- electric currents (moving electrons) create magnetic fields • Magnetic fields on the Sun are electromagnetic • Permanent magnets--iron bar magnets
The Solar Magnetic Field Movie #1 -- Magnetic fields • A movie showing the magnetic field of the Sun and the plasma flowing outward as the solar wind. Perhaps showing interactions with the Earths magnetic field.
The Solar Wind • Continuously emits 1 billion kg/s (1 million tons/s) of material into interplanetary space. • Solar wind has speeds averaging 400 km/s (Detroit to Mackinaw in 1 second) • Consists of charged particles (protons, electrons, and heavier ions) • Solar rotation causes the magnetic field to form a spiral pattern known as the Parker spiral • The heliosphere is a bubble in space created by the solar wind.
Magnetic Features on the Sun Small magnetic fields on the Sun can cause explosions on the surface • http://www.bbso.njit.edu/Images/daily/images/hfull2.jpg www.windows.ucar.edu
Movie #2 • Actual STEREO movie showing magnetic fields and movement of plasma on the Sun • Say something about how the sun just looks like a bright yellow ball in the sky, but through telescopes, it looks much different
What is Solar Activity? Solar activity refers to the increase in the presence or occurrence of the following • Sunspots, Active Regions, Prominences • Solar Flares - Intense energy release observed with strong electromagnetic emissions • Coronal Mass Ejections - Eruptions of mass and magnetic fields • Driven by magnetic fields • Strong, disordered fields result in increased solar activity • The frequency of these events/phenomena varies with the solar cycle • Sun is most active during solar maximum
What is Space Weather? • Space weather is created by electromagnetic energy (light and radiation) from the Sun and by the Sun’s out-flowing atmosphere that streams by Earth (and all planets) at tremendous speeds. • It is a consequence of the behavior of the Sun and other stars, as well as the nature of Earth's magnetic field and atmosphere, and our location in the solar system.
Solar Activity and Space Weather • Enhanced solar activity can lead to more frequent and disruptive space weather events. • The Sun’s and Earth’s magnetic field are key in space weather.
Solar Explosions! • Abrupt changes in the magnetic connections on the Sun release lots of energy. • Solar Flares and Coronal Mass Ejections quickly release vast amounts of energy and material into interplanetary space!
Effects of CMEs • Accelerate atoms in the solar wind. • Make the Northern and Southern Lights on Earth • Causes drag on LEO spacecraft, making the last shorter than planned • Often associated with flares • High radiation • Danger to spacecraft • Drive space weather to a large degree
Movie #4 Affects at Earth • Make a new movie like this showing how the Earth is affected by CMEs
Again, possible content to Movie #4 Simulations • The Earth’s magnetic field responds to changes in the solar wind
Space Weather at Earth -- More possible content for Movie 4 showing interaction of Earth and Sun. Make new movies that incorporate these ideas.
Space Weather Effects • Geosynchronous satellites may end up outside the magnetosphere and can lose their bearings. • The thermosphere can be significantly heated which increases satellite drag. • Induced currents in the ground can cause power disruptions. • Total electron content changes effecting GPS navigation (changes conductivity). • Radiation belt enhancements can cause severe degradation of hardware and electronics. • Solar energetic particles can damage electronics and pose a health risk to astronauts and high altitude pilots.
Space Weather Effects -- Examples • In 1989 The HydroQuebec power grid collapsed after geomagnetically induced currents caused a transformer failure. A 9 hour blackout ensued, affecting 6 million people. All of this was due to a CME. • The AT&T Telstar 401 communication satellite (a $200 million value) was lost in 1997 due to a CME. • Airplanes and pilots on routes near the magnetic pole can be affected. Communications can be disrupted by geomagnetic disturbances. To prevent this, flights are rerouted, costing up to $100,000. • So far, no astronauts have been in space during a large SEP event. If they were up in 1972, they would have received a lethal dose of radiation.
Movie #5 • Put in a movie which describes how we need to use spacecraft to study the Sun. • Highlight the funding missions, WIND, Ulysses, Voyager, ACE (?), STEREO (?)
Conclusions • Space weather is driven by solar phenomena • The Sun couples to the Earth’s magnetic field and the near Earth environment through magnetic fields. • Coronal mass ejections, solar flares and the solar wind are the drivers of space weather. • Space weather events can damage space and ground systems and cause health risks to humans. • In order to improve our understanding and predictive capabilities, we must monitor and model the space environment.
Acknowledgements • Some content provided by D. Knipp (Department of Physics, USAF Academy), T. Bogdan (NOAA SEC), A. Ridley (Department of Atmospheric and Space Science, U of M) • Aly, J.J., On some properties of force-free magnetic fields in infinite regions of space, ApJ, 283, 349-362, 1984. • Antiochos, S. K., DeVore, C. R., & Klimchuck, J. A., A model for solar coronal mass ejections, ApJ, 510, 485-493, 1999. • Chen, J., Physics of coronal mass ejections: A new paradigm of solar eruptions, Sp. Sci. Rev., 95, 165-190, 2001. • Forbes, T. G., A review on the genesis of coronal mass ejections, J. Geophys. Res., 105, 23,153-23,165, 2000. • Low, B.C., Solar activity and the corona, Solar Phys., 167, 217-265, 1996. • Lynch, B.J., Antiochos, S.K., MacNeice, P.J., Zurbuchen, T.H., and Fisk, L.A., Observable properties of the breakout model for coronal mass ejections, ApJ, 617, 589-599, 2004. • Space Science Reviews, March 2006 issue.