Transcript Topics in Space Weather Earth Atmosphere & Ionosphere Sun and Earth: Overview

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
[email protected]
CSI 769
30 August 2005
Sun-Earth System: Energy Coupling
SUN
EARTH
convection zone
radiative zone
core
particles and
magnetic fields
photons
bow
shock
surface
atmosphere
not to scale
sunspot
plage
coronal mass ejection
solar wind
heliosphere
surface
atmosphere
plasmasphere
magnetosphere
Lecture 11
Solar Radiative Output
Lecture 11
Solar Radiation Establishes the Thermal
Structure of the Earth and its Atmosphere
wavelengths < 100 nm
thermosphere/ionosphere
wavelengths 100-300 nm
mesosphere/stratosphere
wavelengths > 300 nm
troposphere & surface
Thermosphere
Ionosphere
Mesosphere
Stratosphere
315
Troposphere
SUN (255 K) + GHG (33 K) = 288 K
Lecture 11
Why does the Atmospheric
Temperature vary with Altitude?
Lecture 12
Ionization:
O, N2, O2 + sunlight  e + …
Lecture 11
Oxygen Heating:
O2 + sunlight  O + O
Ozone Heating:
O3 + sunlight  O + O2
Surface Heating
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
Solar Energy in the Upper Atmosphere
ENERGETIC SUNLIGHT AND PARTICLES
IONIZATION
DISSOCIATION
EXCITATION
NEUTRAL
CHEMISTRY
ION CHEMISTRY
COLLISIONAL
DEACTIVATION
PHOTOELECTRONS
ELECTRON HEATING
SPECTRAL
EMISSIONS
ION HEATING
NEUTRAL HEATING
Lecture 11-13
Why Do We Care About Space Weather?
Lecture 12
Solar Particles and
Plasma Can Affect Earth
Solar, magnetospheric and galactic
particles ionize and heat Earth’s
atmosphere and ionosphere
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
March 1989:
Auroral Oval
Power System Events

www.nas.edu.ssb/cover.html
Lecture 14
LASCO Detector:
1997-11-06
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
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
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
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/