Earth ID: 589

African Vegetation: Comparing July 1984 and July 1994

Visualizations by Jesse Allen Released on January 1, 1999

For many years, scientists have believed that the southern expansion of the Sahara has been due to human activity. However, results from the AVHRR instrument and its measurements of vegetation suggest a different explanation: rainfall patterns. In drier years (1984 was one of the driest summers in recorded history in Northern Africa), the Sahara expands south, but in wetter years (such as 1994), vegetation moves back and there is no net expansion of the Sahara as had been previously suggested.

For More Information

http://svs.gsfc.nasa.gov/stories/NDVI/africa_july8494.html

Visualization Credits

Jesse Allen (Raytheon): Lead Animator
Compton Tucker (NASA/GSFC): Scientist
Sharon Nicholson (Florida State University): Scientist

Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio

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https://svs.gsfc.nasa.gov/589

Data Used:

NOAA-8/AVHRR

1984/07

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NOAA-7/AVHRR

1984/07

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NOAA-12/AVHRR

1994/07

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NOAA-11/AVHRR

1994/07

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Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.

Keywords:
DLESE >> Climatology
DLESE >> Physical geography
SVS >> Sahara
GCMD >> Location >> Africa
NASA Science >> Earth

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0