When it comes to hurricanes, research has come a long
way to help predict when and where a storm will hit.
Forecasting intensity is a much bigger challenge, and
an instrument called HIWRAP will investigate the strength of a storm.
The HIWRAP instrument will fly aboard an aircraft to study storms
from the very large down to the very small scale. Braun: And because those smaller
scales tend to be much chaotic and difficult to predict,
and the interactions between those smaller scales and the large scales is far more
complex, it makes it a huge challenge to try to
improve intensity forecasts. The High-Altitude Imaging
Wind and Rain Airborne Profiler, or HIWRAP, is a
radar designed to examine the factors of storm intensity.
Braun: The HIWRAP Doppler radar is a dual-frequency radar, so it has two frequencies
that measure at two different angles and as the plane is
flying, it's sort of scanning in a cone.
And as it's flying over a particular target--say, the eyewall of a storm--by scanning
in a cone it looks first one way, and then sees the storm from a different direction.
And that's what allows us then to measure the three-dimensional
winds and precipitation within the storm. Because the storm and the aircraft
are both moving, the HIWRAP must send out 5,000 pulses
a second to get an accurate read on precipitation particles,
like rain or ice. The signals that bounce back reveal the type,
size, and distribution of rain or ice particles, as well as
how fast the particles are moving. The speed of the particles can help determine
the wind and circulation in a storm. HIWRAP will provide
scientists with years of unprecedented data that will allow them to
decipher the formation, structure, and intensification
of hurricanes.