65th IHC Booklet/Program (pdf - 4.9MB) - Office of the Federal ...

Microwave sounder observations during GRIP: Preliminary results
Bjorn Lambrigtsen, Shannon Brown
(lambrigtsen@jpl.nasa.gov)
Jet Propulsion Laboratory, California Institute of Technology
The High Altitude MMIC Sounding Radiometer (HAMSR), a microwave sounder similar to but
more advanced than the AMSU sounders now operating on multiple satellites, was deployed on
the Global Hawk unmanned aircraft during the Genesis and Rapid Intensification Processes
(GRIP) hurricane field campaign during August and September 2010. HAMSR was developed at
the Jet Propulsion Laboratory more than ten years ago and has been flown in several hurricane
field campaigns. It was recently upgraded with the latest technology and is now the most
sensitive and accurate sensor of its kind. Using observations from previous field campaigns, a
new algorithm has been developed that makes it possible to emulate a radar and derive
reflectivity profiles from the observed brightness temperatures. We present preliminary results
from GRIP, including close-up views of the convective structure of Hurricane Karl as it
intensified to category 3. The Global Hawk flew over Karl for 13 hours and passed over the eye
20 times during this period, and with HAMSR it is possible to analyze the three-dimensional
convective structure of the inner core as it evolves. And since HAMSR is a sounder, it is also
possible to analyze the thermodynamic structure in areas surrounding the core. GRIP was
operated in coordination with NOAA and the NSF, and observations were collected from
numerous sensors on multiple aircraft platforms. The analysis of this rich data set is just
beginning.
Copyright 2011 California Institute of Technology. Government sponsorship acknowledged.
Session 3 – Page 1