ISS004-E-11807
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Contrail Web over the Central Rhône Valley, Eastern France:
This digital photograph taken through the windows of the
International Space Station on May 15, 2002, shows condensation
trails over the Rhône Valley in the region west of Lyon. Condensation
trails—or contrails—are straight lines of ice crystals that form in
the wake of jet liners where air temperatures at altitude are lower
than about –40°C. Newer contrails are thin whereas older trails
have widened with time as a result of light winds. Because of this
tendency for thin contrails to cover greater areas with time, it is
estimated that these “artificial clouds” cover 0.1% of the planet’s
surface. Percentages are far higher in some places such as southern
California, the Ohio River Valley and parts of Europe, as illustrated
here. The climatic impact of such clouds is poorly understood. In
an unprecedented experiment following the September 11 grounding of
all aircraft in the United States, researchers reported in the August
8 issue of Nature that temperatures in areas usually affected by
contrail blankets fluctuated higher and lower during the
contrail-free period. Despite this dramatic conclusion, it is
nevertheless too early to know whether contrails produce a net
warming or cooling of the atmosphere. Whereas cirrus clouds seem to
have a net warming effect, contrails are denser and thus may produce
the opposite effect. References:
Travis, D. J.,
Carleton, A. M. and R. G. Lauritsen. 2002. Contrails reduce daily
temperature range. Nature 418:601.
9/11 study: Air traffic
affects climate (CNN)
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ISS004-E-11958
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Fires in Central and Southern Africa: Fire scars and smoke
plumes result from biomass burning in the savannas of southern
Democratic Republic of Congo. Astronauts aboard the International
Space Station observed the seasonal increase in savanna burning,
which traditionally peaks in June in southern Democratic Republic of
Congo. This image, taken on May 16, 2002, is centered near 8.6S, 27.4
E. These fires, likely the result of human activities, are thought to
contribute significant emissions to the atmosphere (Cahoon, et al,
1992). The darker area in the foreground is a more heavily wooded
hillside; most burning occurs in the grassier savannas which appear
red-brown. Additional Information:
Seasonal
distribution of African savannah fires, Cahoon, J.; Stocks, B.;
Levine, J.; Cofer, W.; O’Neill, K. , 1992, Nature v.359, p. 812
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ISS004-E-10921
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Pacific NW—Washington, Vancouver Island: This cloudless view
of northwestern Washington and southeastern British Columbia is a
study in varied land-use patterns: the forested Olympic Peninsula and
Cascade Range contrast with the wheatlands of the drier east side of
the mountains. The checkerboard pattern of clearcut forest is
accented by snow in the range east of Seattle. Major cities and
seaports of the Pacific Northwest—Seattle, Tacoma and Vancouver—take
advantage of the deep, sheltered channels. The natural beauty and
safe harbors of the region are products of tectonic processes acting
on the western margin of North America. Mt. Rainier and Mt. Baker are
just two in a line of recently active volcanoes extending from the
Coast Mountains of British Columbia to Mt. Shasta in northern
California. Strong earthquakes are also frequent, as exemplified by
the Nisqually quake (magnitude Mw 6.8) of February 28, 2001, which
rocked Tacoma, Seattle and the surrounding area. Information
Source: Nisqually Earthquake Information Clearinghouse at:
http://maximus.ce.washington.edu/~nisqually/.
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ISS004-E-13304
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Widlfires: Using a handheld digital camera as part of the
ongoing Crew Earth Observations research program aboard the
International Space Station, station crew members took this photo
June 7, 2002, of wildfires in the hills north and northwest of Los
Angeles. Visible in the picture are details of a fire to the north of
Los Angeles.
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ISS004-E-5201
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New Cornelia Mine, Arizona: Although this photograph may
appear to be a small pit mine as photographed from the air, it is
actually a pit mine that is about a mile wide and just over a
thousand feet deep and was photographed by astronauts orbiting the
Earth on board the International Space Station. The New Cornelia Mine
is located just south of Ajo, Arizona. Small-scale mining of copper
in this area began with the Spaniards and Mexicans as early as 1750.
This large-scale, systematic operation began in 1912 and expanded
rapidly for the next 50 years. Since the mid 1980s, activity has been
limited because of low prices for copper on the world market. Note
the tailings deposits to the east (right) and the larger containment
ponds for extraction processes to the northeast.
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ISS004-E-13300
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Wolf and Copper Fires Near Los Angeles: This photograph taken
from the International Space Station on June 7, 2002, shows the Wolf
and Copper Fires burning in the hills outside Los Angeles. Astronauts
use a variety of lenses and look angles as their orbits pass over
wildfires to document the long-distance movements of smoke from the
fires as well as details of the burning areas. In this persepctive
view, you can see the southern end of the San Joaquin Valley at upper
left, and the Channel Islands at lower left. In the background is the
Mojave Desert.
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ISS004-E-13303
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Wolf and Copper Fires Near Los Angeles: This photograph taken
from the International Space Station on June 7, 2002, shows the
Copper Fire burning in the hills outside Los Angeles. Astronauts use
a variety of lenses and look angles as their orbits pass over
wildfires to document the long-distance movements of smoke from the
fires as well as details of the burning areas. This image clearly
illustrates the difficult, rugged terrain that firefighters must face
when fighting these wildland fires.
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ISS004-E-12080
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Saharan Dust over Senegal: Airborne African dust regularly
reaches northeastern South America and the Caribbean. Westward dust
transport from the Sahara across the central Atlantic has been a
common occurrence this spring, with major events visible in both
satellite images and photographs. Cap Vert, the westernmost point of
Senegal, is dimly visible beneath the dust mass (center); the
Arquipélago dos Bijagós in Guinea Bissau lies opposite the mouth of
the sediment-laden Rio Corubal.
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ISS004-E-12328
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Bullock Fire, near Tucson, Arizona: This image of the Bullock
Fire was taken by the crew of the International Space Station using a
digital camera on May 23, 2002, two days after the fire began. By May
25, fighting the fire was listed as the top national priority. The
mountainous region of the Coronado National Forest, northeast of
Tucson, Arizona, is highlighted by the low sun angle when the
photograph was taken. Around 30,560 acres were consumed by the blaze
(which was 85% contained by June 3) but it is still considered
dangerous. Data and maps on the Bullock fire can be found at the
Coronado National Forest Website.
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ISS004-E-10288
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San Francisco Bay: Astronauts aboard the International Space
Station (ISS) recently photographed the San Francisco Bay area. The
gray urban footprint of San Francisco, Oakland, San Jose, and their
surrounding suburbs contrast strongly with the green hillsides. Of
particular note are the Pacific Ocean water patterns that are
highlighted in the sun glint. Sets of internal waves traveling east
impinge on the coastline south of San Francisco. At the same time,
fresher bay water flows out from the bay beneath the Golden Gate
Bridge, creating a large plume traveling westward. Tidal current
channels suggest the tidal flow deep in the bay. Because the ISS
orbits are not synchronous with the sun, astronauts view the Earth
with variable solar illumination angles. This allows them to document
phenomena such as the sun reflecting differentially off surface
waters in a way that outlines complicated water structures.
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