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

Hurricane and Severe Storm Sentinel (HS3): A Multi-year Investigation of Atlantic
Hurricanes
Scott A. Braun 1 , Paul A. Newman 1 , Marilyn Vasques 2
(scott.a.braun@nasa.gov)
1 NASA/GSFC; , 2 NASA/ARC
HS3 is a five-year mission specifically targeted to enhance our understanding of the processes
that underlie hurricane intensity change in the Atlantic Ocean basin. The HS3 science questions
can be distilled down to the extent to which either the environment or processes internal to the
storm are key to intensity change. Is storm formation and intensification mainly a result of
characteristics of the large-scale environment or internal processes? Are these internal processes
driven by large-scale forcing or do they act independently of this forcing?
The HS3 objectives are:
• To obtain critical measurements in the hurricane environment in order to identify the role of
key factors such as large-scale wind systems (troughs, jet streams), Saharan air masses, African
Easterly Waves and their embedded critical layers (that help to isolate tropical disturbances from
hostile environments).
• To observe and understand the three-dimensional mesoscale and convective-scale internal
structures of tropical disturbances and cyclones and their role in intensity change.
The mission objectives will be achieved using two Global Hawk (GH) Unmanned Airborne
Systems (UASs) with separate comprehensive environmental and over-storm payloads. The GH
flight altitudes (>16.8 km) allow overflights of most convection and sampling of uppertropospheric
winds. Deployments from Goddard’s Wallops Flight Facility and 30-hour flight
durations will provide coverage of the entire Atlantic Ocean basin, and on-station times up to 10-
24 h depending on storm location. Deployments will be in September of 2012 and from mid-
August to mid-September 2013-2014, with ten 30-h flights per deployment.
HS3’s suite of advanced instruments will measure key characteristics of the storm
environment and its internal structures. The measurements include:
Measurements from the Environmental GH Payload
• Continuous sampling of temperature and relative humidity in the clear-air
environment from the scanning High-resolution Interferometer Sounder (S-HIS).
• Continuous wind profiles in clear air from the TWiLiTE instrument. TWiLiTE is a
direct detection Doppler lidar capable of measuring the motion of air molecules in clear
air environments.
Session 10 – Page 1