African Vegetation: Comparing September 1984 and September 1994
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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.
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An animation of vegetation changes in North Africa from September 1984 to September 1994, from AVHRR data
Duration: 7.0 seconds
Available formats:
352x240 (29.97 fps)
MPEG-1
1 MB
320x242
JPEG
7 KB
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NDVI measures of African continent, September 1984
Available formats:
1152 x 1152
TIFF
2 MB
256 x 256
GIF
36 KB
512 x 512
JPEG
206 KB
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NDVI measures of African continent, September 1994
Available formats:
1152 x 1152
TIFF
2 MB
256 x 256
GIF
36 KB
512 x 512
JPEG
210 KB
160 x 80
PNG
19 KB
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NDVI measures of north Africa, September 1984
Available formats:
640 x 486
TIFF
581 KB
320 x 243
JPEG
65 KB
80 x 40
PNG
4 KB
160 x 80
PNG
17 KB
160 x 121
GIF
15 KB
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NDVI measures of north Africa, September 1984
Available formats:
640 x 486
TIFF
582 KB
320 x 243
JPEG
67 KB
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NDVI measures of north Africa, September 1994
Available formats:
640 x 486
TIFF
585 KB
320 x 243
JPEG
67 KB
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NDVI measures of north Africa, September 1994
Available formats:
640 x 486
TIFF
586 KB
320 x 243
JPEG
69 KB
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| Animation Number: | 591 |
| Animator: | Jesse Allen (SVS) (Lead) |
| Completed: | 1999-01-01 |
| Scientists: | Compton Tucker (NASA/GSFC) |
| | Sharon Nicholson (Florida State University) |
| Instruments: | NOAA-11/AVHRR
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| | NOAA-12/AVHRR |
| | NOAA-7/AVHRR |
| | NOAA-8/AVHRR |
| Data Collected: | 1984/09, 1994/09 |
| Video: | SVS1999-0008 * |
Keywords:
DLESE
>> Climatology
DLESE
>> Physical geography
SVS
>> Sahara
GCMD
>> Location
>> Africa
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More Information on this topic available at:
stories/NDVI/africa_sept8494.html
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Please give credit for this item to
NASA/Goddard Space Flight Center
Scientific Visualization Studio |
*Please note: the SVS does not fulfill requests for copies of the tapes in our library. On some of our animation pages, there is a direct link to a video distribution service from which tapes, handled by the Public Affairs Office (PAO)/Goddard TV, including some of our animations may be ordered. General information on this service can be found here. |
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