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Topics in Space Weather Earth Atmosphere & Ionosphere

Topics in Space Weather Earth Atmosphere & Ionosphere. Sun and Earth: Overview Physical Processes Effects on Technological Systems. Robert R. Meier School of Computational Sciences George Mason University rmeier@gmu.edu CSI 769 30 August 2005.

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Topics in Space Weather Earth Atmosphere & Ionosphere

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  1. Topics in Space WeatherEarth Atmosphere & Ionosphere • Sun and Earth: Overview • Physical Processes • Effects on Technological Systems Robert R. Meier School of Computational Sciences George Mason University rmeier@gmu.edu CSI 769 30 August 2005

  2. Sun-Earth System:Energy Coupling SUN EARTH convection zone radiative zone core particles and magnetic fields photons bow shock surface surface solar wind sunspot atmosphere atmosphere plage plasmasphere heliosphere coronal mass ejection magnetosphere Lecture 11 not to scale

  3. Solar Radiative Output Lecture 11

  4. Solar Radiation Establishes the Thermal Structure of the Earth and its Atmosphere wavelengths < 100 nm thermosphere/ionosphere Thermosphere Ionosphere wavelengths 100-300 nm mesosphere/stratosphere Mesosphere wavelengths > 300 nm troposphere & surface Stratosphere 315 Troposphere SUN (255 K) + GHG (33 K) = 288 K Lecture 11

  5. Why does the Atmospheric Temperature vary with Altitude? Ionization: O, N2, O2 + sunlight  e + … Lecture 12 Oxygen Heating: O2 + sunlight  O + O Lecture 11 Ozone Heating: O3 + sunlight  O + O2 Surface Heating

  6. SOLAR CYCLE CHANGES IN EUV RADIATION IMPACT UPPER ATMOSPHERE TEMPERATURE and DENSITY Solar Cycle Changes at 700 km: Neutral Temperature: 2 times Neutral Density: 50 times Electron Density: 10 times Lecture 12-13

  7. Solar Energy in the Upper Atmosphere ENERGETIC SUNLIGHT AND PARTICLES IONIZATION DISSOCIATION EXCITATION NEUTRAL CHEMISTRY ION CHEMISTRY COLLISIONAL DEACTIVATION PHOTOELECTRONS SPECTRAL EMISSIONS ELECTRON HEATING ION HEATING NEUTRAL HEATING Lecture 11-13

  8. Why Do We Care About Space Weather?

  9. Solar Particles and Plasma Can Affect Earth Lecture 12 • Solar, magnetospheric and galactic particles ionize and heat Earth’s atmosphere and ionosphere March 1989: Auroral Oval Power System Events • spacecraft drag, collisions, loss • communications & navigation • aurora • currents induced in power grids • spacecraft detector upsets • hazards to humans in space • ozone depletion in major events • speculated climate impacts LASCO Detector: 1997-11-06 www.nas.edu.ssb/cover.html Lecture 14

  10. Solar Variability Can Affect Human Space Flight •Radiation Protection operations for future human missions (both to the ISS and to Mars) should be provided with observations of CME’s from several vantage points, such as would be provided by SOHO and STEREO. • • Space Station Orbit is Exposed to High Energy Solar Particles • Space debris can collide with the Space Station Oct 20, 1989 Solar Protons NOAA-10 Lecture 14

  11. IONOSPHERE ELECTRON DENSITIES Communication, Navigation • disrupts communications • degrades radar accuracy • space-based & surveillance • radars, HF OTH • disrupts/degrades navigation • VLF Omega, GPS • degrades precision targeting Lecture 14

  12. Thousands of Objects Orbit the Earth in the Upper Atmosphere • remote sensing • surveillance • weather monitors • communications • navigation • science The Naval Space Surveillance radar tracks 12,000 + resident space objects larger than 20 cm Lecture 14

  13. Space Weather Data Sites • National Space Science Data Center • http://nssdc.gsfc.nasa.gov/space/ • OmniWeb • solar wind and geomagnetic data • http://nssdc.gsfc.nasa.gov/omniweb/ • Space Physics Models • http://nssdc.gsfc.nasa.gov/space/model • Solar Activity Reports • http://www.dxlc.com/solar/ • Current Space Weather Conditions • www.spaceweather.com • Space Weather Today • http://www.windows.ucar.edu/spaceweather/

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