Fire season in Manitoba, Canada lasts from April until October,
and numerous smoke plumes caused by lightning strikes are captured
in these Multi-angle Imaging SpectroRadiometer (MISR) views of the
northwestern part of the province. The data were acquired on
June 20, 2001 during Terra orbit 8015.
On the left is a true-color image acquired by MISR's vertical-
viewing (nadir) camera. The area covered measures 232 kilometers x
80 kilometers. The greenish area on the right-hand side of the image,
partially obscured by clouds, is Southern Indian Lake. This landscape
is predominantly boreal, and contains deciduous and evergreen conifer
forests, deciduous broadleaved forests, fens, and lakes. Tree species
found within the area include white and black spruce, jack pine,
tamarack, willow, and birch. Human population density is sparse,
averaging about 1 person per 10 square kilometers.
During the fire season, information is updated daily on the
Manitoba Conservation website (http://www.gov.mb.ca/natres/fire/).
The large plume northwest of Big Sand Lake, above image
center, was reported to be under control on June 20, whereas the
plume at lower left, to the west of Gold Sand Lake, was classified
"out of control". In the next two days, an additional 27 out-of-control
fires in the area were started by lightning strikes arriving with a
slow-moving northerly cold front. By June 29, all but six of the fires
had been brought under control.
The picture on the right is a height field derived using automated
computer processing of the data from several of MISR's cameras.
The results indicate that the smoke plumes reach altitudes a few
kilometers above the surface terrain, nearly as high as the cumulus
cloud field in the lower right quadrant. The height retrievals make
use of geometric parallax associated with observing the features at
multiple angles. A few artifacts are visible in this early version
of the MISR stereoscopic product, e.g., linear discontinuities in
the elevation field, isolated elevation "spikes" (appearing as red),
and black areas where no result was obtained. Nevertheless, this first
version of the algorithm, which is designed to operate autonomously and
rapidly without human intervention, is doing a good job at detecting
the smoke plumes and cloud field. Improvements are anticipated in the
future. The product was generated as part of operational processing
at the NASA Langley Atmospheric Sciences Data Center.
Image credit: NASA/GSFC/LaRC/JPL, MISR Team.
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