Hurricane and Severe Storm Sentinel (HS3): the 2014 Season BeginsAugust 28th, 2014 by Mary Morris
Welcome to the HS3 blog! My name is Mary Morris and I am a graduate student studying atmospheric science at the University of Michigan. Over the next few weeks I will be posting about my experiences while I participate in the HS3 mission at NASA Wallops Flight Facility.
HS3 is a mission designed to investigate the processes that control hurricane formation and intensification. In order to collect observations of hurricanes we have two unmanned aerial vehicles (UAVs) outfitted with meteorological instruments that we can fly for long distances to reach hurricanes and storms forming in the Atlantic Ocean basin. On one of those UAVs, AV-1, is an instrument called the Hurricane Imaging Radiometer, or HIRad. My graduate research is currently focused on extracting surface wind speed and rain observations from HIRad data, so participating in the collection of HIRad data is an exciting opportunity. While the HIRad team has been here at Wallops since August 25th, we are still awaiting AV-1’s arrival. Until then, HS3 scientists will be relying solely on the other UAV, AV-6, to investigate hurricanes.
Wallops Flight Facility (WFF) welcomed AV-6 back from Armstrong Flight Research Center (AFRC) on August 27th. On the way to WFF, AV-6 was able to get a good set of observations of Hurricane Cristobal. In order to collect data on the storm’s environment, AV-6 uses three types of instruments. First, dropsondes are—you guessed it—dropped from AV-6 to gather information about air temperature, dewpoint, atmospheric pressure, and winds. Dropsondes are similar to weather balloons. The Scanning High-resolution Interferometer Sounder, or S-HIS, is used to gather information about air temperature and water vapor. And finally, the Cloud Physics Lidar, or CPL, is used to gather information about clouds and aerosols in the atmosphere. All of these observations are helpful for analyzing the environment of a hurricane.
Since the UAVs can fly long distances, we are going to get a good second look at Cristobal later tonight and tomorrow. HS3 scientists are particularly interested in observing Cristobal as it interacts with a frontal zone. As Cristobal interacts with the frontal zone, it will lose the characteristics that make it a tropical cyclone and gain characteristics that will make Cristobal an extratropical cyclone. In short, the differences between these two types of cyclones have to do with where the cyclones get their energy. With the NOAA Hurricane Hunters collecting data on Cristobal from the beginning, and with HS3 following up on Cristobal tonight, atmospheric scientists will have lots of observations that document Cristobal’s life cycle. These observations will then help scientists as they continue to research the processes that underlie hurricane formation and intensification.