VO: The Tropical Rainfall Measuring Mission, or TRMM, was launched in November
of 1997 to precisely measure falling rain throughout
the tropics. Eighteen years and thousands of storms later, TRMM has contributed
to the advancement of scientific milestones.
TRMM has advanced
research in the areas of agriculture, disease tracking,
precipitation physics, and natural hazards. Scott: We get
roughly three hourly rainfall estimates across much of the globe
at fairly high resolution, and these rainfall estimates are used to
monitor major rainfall events and to look for events
that might lead to significant flooding, even landslides,
and there are a number of groups that have been using it as sort of an early warning
system.
VO: TRMM's unforeseen
longevity has provided more robust information on weather and climate patterns
that can only be seen after years of observations. This nearly two decades
of data lets scientists see variations in rainfall from year to year,
how El Nino effects rain patterns worldwide, and the anatomy
and life cycle of major storms, like hurricanes. Scott: It's also proven to be
an extremely useful satellite for understanding hurricanes
partly because its orbit stays within the tropics so you get much more
frequent observations. And it's just provided a wealth of
rainfall information over its relatively short time period that
in many ways surpasses all of the information that we had prior
to that.
VO: From giant storms
to individual droplets, TRMM also provides scientists with data on the
precise physics of falling raindrops. Scott: TRMM has a unique set of
instruments, including the first and only precipitation radar in space,
it also has a microwave imager, which is an instrument that can give you
the equivalent of an X-ray of a storm, whereas the radar is giving you
more of a CAT scan of the storm. It provides
extremely valuable information on the structure, rainfall structure,
of storms, which tells us something about how the
storm is responding to its environment, whether or not it might intensify
or weaken in the upcoming hours.
VO: As TRMM's mission ends, the Global Precipitation Measurement mission builds
on TRMM's objectives. Launched in early 2014,
GPM's two instruments are more advanced and more sensitive versions of TRMM's microwave
imager and precipitation radar. GPM's orbit extends
coverage beyond the tropics and provides measurements of light to heavy rain and snow,
expanding TRMM's legacy into the future.