Astronaut Photography - Observing Earth's Systems from Space
by Rebecca Dodge in collaboration with NASA scientists
Aerosols and particulates introduced into the atmosphere by fires not only threaten life in the ocean, but also create health threats on land by contributing to fire-generated smog23. Crew Earth Observations photographed a portion of widespread fires in San Bernardino Mountains of southern California24 in late October of 2003 (top left).
23. (http://eol.jsc.nasa.gov/EarthObservatory/FiresinSouthernCalifornia.htm Fires in Southern California
24. (http://earthobservatory.nasa.gov/Library/BiomassBurning/biomass_burning.html Biomass Burning)
Over one week later atmospheric conditions still trapped the extensive pall of smoke and ash that had moved northwards into the California Central Valley24, creating "fire smog" conditions and associated health hazards.
25. (http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16369 Fire Smog in the Central Valley of California)
Atmospheric observations are needed to evaluate the effects of every source of aerosols - dust, smoke, and smog. Recent research suggests that aerosols from dust, biomass-burning smoke and urban air pollution all serve to reduce local rainfall wherever they enter the atmosphere, and over the typically broad regions into which the aerosol matter moves26. Crew Earth Observations will observe smog in support of scientists' efforts to understand smog and other aerosols' effect on both local and global climate. Smog has relatively high albedo and tends to reflect sunlight, lowering ground temperatures in smog-covered locations. Smog is mobile, achieving regional impact beyond its source. As with dust observations, the oblique viewing angles available from the astronaut photographs enables scientists to better discriminate smog pall thickness and boundaries within the atmosphere.
26. (http://earthobservatory.nasa.gov/Newsroom/NasaNews/2001/200105154721.html Droughts Aggravated by Dust in the Wind)
The ISS is particularly well-situated to observe the atmosphere with its capability to view the Earth's limb27, the thin layer of atmosphere surrounding Earth. Astronauts use this viewing capability as part of the Crew Earth Observations program to support scientists' study of the distribution of gases, clouds, and aerosols in the atmosphere.
27. (http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=13773 Viewing Earth's Limb
28. (http://earthobservatory.nasa.gov/Library/Aerosols/aerosol.html Aerosols and Climate Change)
Crew Earth Observations >>
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Coral Reefs >>
El Nino >>
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