| This is a TIMS image acquired over southwestern France during the HAPEX-MOBILHY
experiment in 1986. The image was taken in mid-afternoon from a 6 km altitude yielding 15
m resolution and is roughly 15 km by 10 km. The range of temperature is from high 20's to
the low 50's. There are 3 fields identified in the scene for which surface flux
measurements were made. A well irrigated oat field (T = 30C), a corn field with
significant bare soil showing (T = 45 C) and a pine forest (T = 30C). The sensible heat
flux for the corn and oat fields reflect the differences in surface temperature,with it
being about 0 for the oat field and 110 W/M*M for the hotter corn field, while for the
pine forest the sensible heat was much greater, about 200 W/M*M, because of its more
efficient heat transfer. These results show that it is possible to estimate the heat flux
from surface temperature measurements provided we know something about nature of the
surface that we are observing. An example of this will be given on the next page. The
redness in the fields is due to the emissivity differences amongst the 3 TIMS channels
shown. Channel 5 is on the red gun and thus has the greater emissivity than channels 3 and
1 on the green and blue guns. |
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