Our Magnetic Sun and its Effects on Earth Dr. E.J. Zita The Evergreen State College Women in Science Symposium 12 April 2006, TESC Chemistry Club This work was supported by NASA's Sun-Earth Connection Guest Investigator Program, NRA 00-OSS-01 SEC
Energy flows out of the Sun
Magnetic fields channel energy flow
Magnetic waves heat the Sun’s atmosphere to millions of degrees T h
Magnetic sunspots → solar flares
Solar outbursts → auroral effects
What causes cycles of solar magnetism?
Sun’s magnetic field flips ↑ ↑ tachocline photosphere
Solar magnetic activity → solar atmosphere heating → warmer Earth? Solar max: more sunspots Strong, twisted B fields Magnetic tearing releases energy and radiation Cell phone disruption Bright, widespread aurorae Solar flares, prominences, and coronal mass ejections Global warming? next solar max around 2011
Does solar variability change Earth’s climate? Friis-Christensen & Lassen (1991) Lean & Rind (2002) Lean & Rind (2001)
Other factors affecting Earth’s climate Fire & Water, Fall 2006
What does the future hold? Global warming? Ice age? More extreme weather!
Acknowledgements We thank the High Altitude Observatory (HAO) at the National Center for Atmospheric Research (NCAR) for hosting our summer visits; computing staff at Evergreen for setting up Linux boxes with IDL in the Computer Applications Lab and Physics homeroom; and NASA and NSF for funding this research. The National Center for Atmospheric Research is sponsored by the National Science Foundation.
References Song, N., Zita, E.J., McDonald, E., Dikpati, M., “Influence of depth-dependent magnetic diffusivity on poloidal field evolution in the Sun,” 2005, Proceedings of the Astronomical Society of the Pacific Bogdan, T.J., Carlsson, M, Hansteen, V., McMurray, A, Rosenthal, C.S., Johnson, M., Petty-Powell, S., Zita, E.J., Stein, R.F., McIntosh, S.W., Nordlund, Å. 2003, “Waves in the magnetized solar atmosphere II”, ApJ 597 Bogdan, T.J., Rosenthal, C.S., Carlsson, M, Hansteen, V., McMurray, A, Zita, E.J., Johnson, M.; Petty-Powell, S., McIntosh, S.W., Nordlund, Å., Stein, R.F., and Dorch, S.B.F. 2002, “Waves in magnetic flux concentrations: The critical role of mode mixing and interference,” Astron. Nachr. 323, 196 Canfield, R.C., Hudson, H.S., McKenzie, D.E. 1999, “Sigmoidal morphology and eruptive solar activity,” Geophysical Research Letters, 26, 627 * Noah Heller, E.J. Zita, 2002, “Chromospheric UV oscillations: frequency spectra in network and internetwork regions” * Matt Johnson, Sara Petty-Powell, E.J. Zita, 2001, “Energy Transport by MHD waves above the photosphere” B.C. Low, 1988, Astrophysical Journal 330, 992 * Zita, E.J. 2002, “Magnetic waves in sheared field regions” HAO = High Altitude Observatory: NCAR= National Center for Atmospheric Research: Montana St. Univ., SOHO = Solar Heliospheric Observatory: SUMER = Solar Ultraviolet Measurements of Emitted Radiation: Papers online:
Sources of figures Shindell et al. ( Robert Stewart ( ETE team ( Judith Lean and David Rind, Sun-Climate Connections: Earth's Response to a Variable Sun, Science, Vol 292, Issue 5515, (2001 ) Friis-Christensen, E.Friis-Christensen, E.; Lassen, K., Science, 254, (1991)Lassen, K. D. Rind (courtesy of J. Lean), The Sun's Role in Climate Variations Science, Vol 296, Issue 5568, (2002) Jada Maxwell’s auroral research: energy0405/students/jada/ auroral_waves.htm
Sources of figures … The Earth Institute, Columbia University ( Atelier Changement Climatique, ENPC ( carbone.htm) carbone.htm Richard Dewey, UVic, BC ( Scott Rutherford, Roger Williams Univ., RI, Milankovitch Cycles in Paleoclimate, ( E.J. Zita, solar physics research at Evergreen and HAO/NCAR
NOAA News: Arthropolis: daftanddemented.moonfruit.com/storms Wilcox Solar Observatory: NASA Solar Physics – Marshall Institute – Greenwich Observatory: Bjorn Jorgensen, 18 January 2005, near Tromsø, Norway Tom Michalik - Sources of figures …