figure 40c. MCC
GOES 7, IR. July 25, 1993–2200 CDT.
image courtesy of M. Ramamurt h y, University of Illinois, Urbana/Champaign
During summer and fall months, the most arresting weather developments are tropical
hurricanes. Because hurricanes travel long distances during their lifetimes, the best
way to observe them is through a series of GOES images. Hurricanes are observed in
the eastern Pacific in the summer months and become frequent in the Atlantic during
the late summer and early fall. The strongest Atlantic hurricanes typically develop from
waves in the easterly trade-wind-flow off the coast of Africa. Clusters of convective
clouds with cold tops can be seen in GOES IR images and can then be tracked across
the Atlantic. As the hurricane moves closer to land, polar-orbiter images can be used to
resolve the finer scale of the hurricane, including the bands of clouds that circle around
the core ( ) of the hurricane. In figure 41 (page 60), a polar orbiter image of
Hurricane Emily is shown off the coast of North Carolina.
noise
Reception of satellite images is often affected by local sources of interference—
noise. Common sources of interference are household appliances, motors
(heating and cooling, vacuum cleaners, etc.), radio and aircraft transmissions,
automobiles, and fluorescent lights. The higher the frequency, the less suscepti-
ble the receiving equipment is to noise (geostationary reception is less affected
than polar-orbiting satellite reception). On satellite images, interference typically
appears as horizontal stripes. Examples of noise appear in figures 40a and 40b.MCC