Topics in Space Weather Earth Atmosphere

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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_at_gmu.edu CS
I 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
plage
atmosphere
plasmasphere
heliosphere
coronal mass ejection
magnetosphere
Lecture 11
not to scale
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Solar Radiative Output
Lecture 11
4

Solar Radiation Establishes the Thermal Structure
of the Earth and its Atmosphere
wavelengths lt 100 nm thermosphere/ionosphere
Thermosphere Ionosphere
wavelengths 100-300 nm mesosphere/stratosphere
Mesosphere
wavelengths gt 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
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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
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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
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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 Earths 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 CMEs
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
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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/