VO: Launched from Japan on February 27,
2014. the NASA/JAXA Global Precipitation Measurement mission. or GPM.
has changed the way we see precipitation. It has
provided unprecedented three-dimensional views of everything from
light rain to intense thunderstorms. To mark its five years, we’re looking
back at five big moments in GPM’s history of observing storms.
[Music]
VO: Not long after its launch in 2014, the GPM Core
satellite captured Super Typhoon Vongfong as it headed for Japan.
Braun: Super Typhoon Vongfong was one of the first Category 5
intensity cyclones that GPM was able to observe. VO: The radar
data revealed a clear eyewall with bands of rain encircling it, forming a
secondary eyewall. GPM was able to observe Vongfong as it
weakened. Braun: So the reason that Vongfong was weakening at this time
is what we refer to as an eyewall replacement cycle. So those bands outside
of the eyewall, forming a circle. They essentially cut off the inflow to
the storm. [Music]
VO: Hurricane Harvey slammed into Texas and
Louisiana in August 2017, dumping feet of rain,
making it the wettest tropical cyclone on record in the United States.
GPM was able to see the full structure of the hurricane beyond
the reach of ground-based radars. Huffman: As Harvey perched over Houston,
it became highly asymmetric with a large area of rainfall to the north
and almost no rainfall to the south. VO: The GPM mission was able to observe
the historic rainfall estimates over land and ocean, shedding light
on the structure and magnitude of the storm’s impacts.
[Music]
VO: Later in the 2017 Atlantic Hurricane season, GPM was able to see
the evolution of Hurricane Ophelia. Braun: What was interesting about Ophelia
was the fact that it formed sort of from a decaying extratropical frontal system,
what we call a tropical transition, going from an extratropical system to a tropical
one. It managed to intensify up to a Category 3
hurricane in the eastern Atlantic, and this was the farthest east that we’ve had a storm
of that intensity in the satellite record.
VO: Later, Ophelia raced off to the northeast, bringing severe winds to the United Kingdom
and Ireland. [Music]
VO: On January 4, 2018, a large snowstorm
rapidly intensified as it moved from the southeastern U.S. up
the east coast. Braun: In fact it intensified so rapidly in terms of the drop of
pressure at the center it was called a “bomb cyclone” and intensified about as
much as you’d see with an intense hurricane. VO: GPM clearly depicted
the transition from rain to snow, shown here as the rain layer
in green, yellow and red becomes shallower and thinner as it progresses
northward into snow, show in blue.
[Music] VO: The GPM mission
joins together data from an international satellites to create a
global picture of precipitation in the Integrated Multi-satellitE
Retrievals for GPM, or IMERG for short. Huffman: The great thing about
IMERG is that the fine scale, in space and time, allows
you to really see the details, and they flow smoothly from image to the next.
When you look at this particular week of IMERG, you see some very general patterns:
You see the high precipitation in the tropics, lower
precipitation to the north and south of that, and then the storm tracks in midlatitudes.
VO: For five years, GPM data has advanced our understanding
of how hurricanes form and intensify, demonstrated how individual
raindrops are distributed inside storms, and produced
unparalleled global coverage of precipitation across land and sea.
[beeping]