Overview
The satellite page contains links to National-scale and regional-scale satellite images from the
GOES-11 (West) and
GOES-13 (East) satellites.
There are also links to satellite images with the
LIFR/IFR/VFR/MVFR
icons overlaid. Images are provided for three of the different wavelength sensors on the satellite:
Visible
The visible images display the Earth similarly to how humans see it
with their eyes or how typical cameras view it. Clouds and snow appear
bright white (high albedo/reflectance) but oceans and trees are much
dimmer.
IR
The infrared images display the Earth in a manner that correlates
with temperature. Generally speaking, the warmer an object, the more
infrared energy it emits (gives off). The satellite sensor measures
this energy and calibrates it to temperature using a very simple
physical relationship (Planck's Law). In the real world, clouds that
are very high in the atmosphere are generally quite cold (perhaps -50
°C) whereas clouds that are very near the earth's surface can be
quite warm (perhaps +5 °C). Likewise, the land may be even warmer
than the lower clouds (perhaps +20 °C). Those colder clouds emit
much less infrared energy than the warmer clouds and the land emits
more than those warm clouds. The data measured by the satellite are
calibrated and colorized according to the temperature with red shades
representing higher (warmer) temperatures and blue shades representing
lower (cooler) temperatures. If the temperature of the atmosphere
decreases with height (which is typical), a user can get an idea of
which clouds are high-level and which are low-level based on the cloud
top temperature.
Water vapor
The water vapor images display the Earth in a manner that correlates
to quantity of water vapor in the upper portions of the atmosphere
(25,000 feet and higher in general). The actual numbers displayed on
the water vapor images correspond to temperature but there is no direct
relationship between these values and the temperatures of clouds (as is
the case for infrared images) since this channel doesn't really "see"
clouds but "sees" high-level water vapor instead. The most useful
information to be gained from the water vapor images is the locations
of storm systems and the jet stream. The color scale on the images can
be helpful in interpreting the water vapor images. In general, regions
displayed in shades of red are VERY dry in the upper atmosphere and MAY
correlate to crisp blue skies from a ground perspective. On the
contrary, regions displayed in shades of blue or green are indicative
of a significant amount of high-level moisture and may also indicate
cloudiness. This cloudiness could be high-level cirrus types or serious
storms. That determination can only be made when this image is used in
conjunction with the other channels.