El Niño cycles |
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El Niño Southern Oscillation (ENSO) cycles occur every few years, disrupting weather patterns around the world. The human and economic tolls from extreme droughts and floods can be great (see the Earth Observatory Reference on ENSO). ENSO events affect rainfall patterns, leading to droughts in some places and extraordinary rainfall in others. Astronauts track indicators of drought such as increased incidence of wildfires and lowered levels of lakes and reservoirs. Where rainfall increases, they observe floods and vegetation greening. The International Space Station crews will collect comparative photographs over parts of the world that were hardest hit by precipitation anomalies associated with the 1997-1998 El Niño. These new observations will build on the unprecedented data on El Niño-related floods and droughts that were collected by astronauts living on Mir (Evans et al. 2000). |
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Imagery from space provides regional context for local events like
floods or fires. The presence of smoke, the boundaries of smoke palls,
and lake level fluctuations can be compiled for a regional and global
assessment of El Niño impact. Rising and falling water levels in
lakes, reservoirs and rivers, and vegetation characteristics can be
monitored repeatedly to determine responses and rates of response to
extreme weather events. |
Fires resulting from severe drought choke Indonesia during the beginning of the 1997-98 El Niño event. The photographs were taken from the Space Shuttle in September 1997 using an electronic still camera as part of the EarthKAM Project (STS086.ESC.00215701) | ||
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Heavy rainfall over the Horn of Africa resulted in flooding. This pair of images shows the remarkable greening of desert vegetation in Somalia. The first image, NM21-727-6was taken in March 1996. | ||
Other sites that are targeted for Crew Earth Observations include Lake Poopó, Bolivia; Lake Eyre Australia; Central California; Lake Nasser, Egypt (See Earth Observatory Image); and the lower Paraná River, Argentina. |
The second image, NASA6-708-56 ],was taken in January 1998. The large light-colored patches on the coast are dune fields. | ||
