Smog |
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Dense smog blankets are light gray and reflect a small amount of the sun's energy back into space. This effect reduces the local degree of warming of the atmosphere by roughly 25 percent of the heating due to the greenhouse gases (Charleson and Wigley 1994). The location, size, movement, and duration of such smog blankets is of great interest to atmospheric scientists and climatologists. |
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According to atmospheric models, the greatest reflective cooling of this kind occurs over the major industrial regions of the world–Northwestern Europe, Northeastern North America, and East Asia. Thus, some models suggest that smog over industrial centers induces regional cooling, even though the greenhouse gases in the smog result in heating of other parts of the planet. Photographs from the Space Station will be useful for visualizing the
location, extent and rapid changes of smog palls over industrial regions
(Wilkinson et al. 2000). Oblique viewing angles amplify the apparent
density of the smog and make it easier to identify boundaries in
handheld photographs than in satellite images. |
The photograph (STS031-151-155) looks obliquely north up the east coast of the United States with the Florida peninsula in the foreground to the left. A smog pall from the northeastern U.S. industrial regions flows out into the Atlantic Ocean across the top of the view; it was thick enough on the day this photo was taken (26 April 1990) to obscure the coastline of the Mid-Atlantic states (top center). | ||
By combining photographs from the Space Station with other weather data, a greater understanding of movements of aerosols will be obtained. For example, the photograph above shows the leading edge of the pall (far right) curving back towards Florida, guided by the winds blowing around the high pressure system (arrows on line diagram). Within hours of this photo being taken, the smoggy air from the northeastern United States drifted across Miami from the sea (lower arrow in line diagram), an unexpected direction. As part of the Crew Earth Observations project, astronauts will photograph accumulations of smog, with emphasis on the Northeastern United States, China, Sub-Saharan Africa, and Europe. |
Weather charts from the National Climate Data Center on the date when the photograph was taken show that the Bermuda High pressure system was centered over the southeastern United States, its winds transporting the smog eastwards (upper arrow in line diagram) all the way to Bermuda (B on the photo), which is roughly 1500 km east of Cape Hatteras. | ||
