Space Weather

1. Space Weather The coupling of the Solar-terrestrial systems

2. Unit Outline • Earth’s internal structure, atmospheric structure, and magnetosphere • Solar General Structure • Solar activity at or above the photosphere • Space Weather

3. Earth structure

4. The Atmosphere

5. Sources for any natural magnet Imbalanced atomic dipole moments result in orientation of field lines and bulk magnetic properties of some elements and compounds. Geomagnetism a form of ferromagnetism resulting from the atomic properties of the iron, cobalt, and nickel that make up the internal portions of the earth as well as the coupling forces of the crystal lattices in the solid state which serve to align the atomic dipoles and generate bulk magnetic fields. Further reading on magnetism Geo-magnetism http://www.rare-earth-magnets.com/t-magnetism.aspx

6. Complex Fields that are ever changing Images on wikipedia common media license

7. Solar Structure Solar Structure

8. General Structure • The sun contains no solid matter • Light we ‘see’ is from photosphere (very thin, 500 km thick) • This gives the sun the appearance of having a sharp edge to it.

9. General Structure Interior Model • Assume Hydrostatic Equilibrium • Outward pressure of hot gas balances the inward pull of gravity Outward force = inward force

10. Patterns of Density and TemperatureBoth decrease with distance from the core General Structure

11. General Structure Evidences of internal structure Spectral lines of certain elements are doppler shifted Images on wikipedia common media license

12. General Structure Evidence of internal structure • Surface of the sun oscillates or vibrates with certain frequency • Surface patterns result from internal pressure waves that reflect off of the photosphere • Propagation of these pressure waves through the interior allows scientists to model the density and temperature profiles as well as internal movement of material. Images on wikipedia common media license

13. General Structure Evidence cont. • From the photospheric expression of moving (doppler shifted) gas, we can map out the internal structure • Models match observations quite well Images on wikipedia common media license

14. Active features of the photosphere Sunspots appear dark because slightly cooler than surroundings. Images on wikipedia common media license

15. 9.4 The Active Sun Active features of the photosphere Sunspots come and go, typically in a few days. Sunspots are linked by pairs of magnetic field lines. http://www.windows2universe.org/sun/sun_polar_regions.html

16. The Active Features of the Photosphere 9.4 The Active Sun The Sun has an 11-year sunspot cycle, during which sunspot numbers rise, fall, and then rise again.

17. The Active Features of the Photosphere 9.4 The Active Sun This is really a 22-year cycle, because the spots switch polarities between the northern and southern hemispheres every 11 years. Maunder minimum: few, if any, sunspots. Images on wikipedia common media license

18. The Active Features of the Photosphere Areas around sunspots are active; large eruptions may occur in photosphere. Solar prominence is large sheet of ejected gas. http://soho.nascom.nasa.gov/gallery/

19. 9.4 The Active Sun Active features of the photosphere The rotation of the Sun drags magnetic field lines around with it, causing kinks. A Prominence can be seen when a loop is near the edge.

20. A Solar flare is a large explosion on Sun’s surface, emitting a similar amount of energy to a prominence, but in seconds or minutes rather than days or weeks. http://soho.nascom.nasa.gov/gallery/

21. A coronal mass ejection emits charged particles that can affect the Earth. http://soho.nascom.nasa.gov/gallery/

22. 9.4 The Active Sun Solar wind escapes Sun mostly through coronal holes, which can be seen in X-ray images. http://soho.nascom.nasa.gov/gallery/

23. 9.4 The Active Sun Solar corona changes along with sunspot cycle; is much larger and more irregular at sunspot peak.

24. Solar wind – a fast moving flux of radiation and charged particles interacting with earth’s magnetic field. "Parts of the Sun." SOHO-Gallery. Web. 01 Aug. 2014. http://soho.nascom.nasa.gov/gallery/

25. Solar inputs and Earth’s Outputs http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php

26. The paths of energy through the atmosphere Images on wikipedia common media license

27. Space Weather Detection of a Solar Flare Solar Flare events happen in stages The first stage, or the precursor stage, the build-up of magnetic energy triggers the event and can be seen via soft x-rays The second stage, impulsive stage is where the massive amount of energy is released across almost all spectra Especially the Radio Spectrum!!!

28. Space Weather The Ionosphere - As a boundary between the solar wind magnetosphere and atmosphere, it can be a sensor for the influence of space weather on the atmosphere

29. Space Weather Interactions of solar wind and earths magnetosphere

30. Space Weather Coronal Mass Ejections (CMEs) Often associated with solar flares Extremely large ejections of solar wind and energy Has a larger push on Earth’s magnetosphere than normal causing more extreme disturbances in our upper atmosphere http://en.wikipedia.org/wiki/File:Solar_Storm_on_August_1,_2010.OGG http://en.wikipedia.org/wiki/File:Close-up_on_launching_filament_%28SDO-AIA,_304_%C3%85%29.ogv http://en.wikipedia.org/wiki/File:A_Coronal_Mass_Ejection_strikes_the_Earth.ogv

31. Space Weather Case Study: The 2003 Halloween Storm This solar CME caused a massive geomagnetic storm that resulted in power outages in northern Europe. "Parts of the Sun." SOHO-Gallery. Web. 01 Aug. 2014. http://soho.nascom.nasa.gov/gallery

32. Space Weather Aurora Borealis (The Northern Lights) Images on wikipedia common media license

33. Space Weather The Halloween storm of 2003 created many disturbances in the atmosphere were studied for years afterward

34. Studying the Ionosphere with Radio waves Two methods: Ionosonde Use radar from the ground or from satellite. • A huge pulse of radio waves (Megawatts) is reflected off of ionosphere • Return signal contains information about the structure, temperature, and ion content of the ionosphere. Image from: http://www.amateur-radio-wiki.net/index.php?title=File:Ionosonde.jpg

35. Studying the ionosphere with Radio Use current GPS/GNSS system • For GPS navigation our receivers are constantly sending radio signals back and forth from the satellites. • The ionosphere interferes with these signals and the level of interference can be used by scientists to estimate properties of the ionosphere. A. Coster 2013 MIT Haystack

36. Summary Geospace environment includes solar inputs of radiation and high energy particles Variations in the solar wind from events like CMEs, flares, promenances, faculae,…. May cause geomagnetic disturbances or storms Monitoring the ionosphere is important for understanding the effect of solar variability on earths environment for engineering purposes as well as climate change.

37. References • http://www.rare-earth-magnets.com/t-magnetism.aspx • Free GNU license agreement http://www.gnu.org/copyleft/fdl.html • "Parts of the Sun." SOHO-Gallery. Web. 01 Aug. 2014. http://soho.nascom.nasa.gov/gallery/ • http://gnss.be/atmosphere_tutorial.php • Hathaway, David H. "Sun Spot Cycles." NASA/Marshall Solar Physics. NASA/Marshall, 4 July 2014. Web. 04 Aug. 2014. http://solarscience.msfc.nasa.gov/SunspotCycle.shtml • http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php • "Climate and Earth’s Energy Budget : Feature Articles." Climate and Earth’s Energy Budget : Feature Articles. Web. 08 Aug. 2014. <http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php>.

38. Shapley, Patricia. "Our Energy Budget." Our Energy Budget. University of Illinois, 2012. Web. 08 Aug. 2014. <http://butane.chem.uiuc.edu/pshapley/GenChem2/C1/1.html>.