28 Aug 2010 Global Hawk Platform Scientist Report (Frank) - Gerry Heymsfield

28 Aug 2010 Global Hawk Platform Scientist Report (Frank) - Gerry Heymsfield

The Global Hawk performed its first flight over Frank that was a tropical storm the prior day and was rapidly weakening to a tropical depression and sub depression category during the flight.  The flight was fantastic for a first science flight and we learned a lot about the operation of the Global Hawk. The "square spiral" flight pattern was planned for Frank  since there was considerable convection observed on August 27.  The Global Hawk took off at 12:56 UTC and returned at approximately 04:00 UTC.   The convection and whole top of Frank was was sheared off to the northwest of the low, exposing the low level circulation.  The plane starting executing the square spiral pattern and near 22:45 UTC, a line of convection began rapidly building near the circulation center, and subsequently developed cold IR temperatures and an anvil.  The temperatures were never less than -60 C, so the pilot (Dee Porter) and co-pilot (Phil Hall) were eager to go directly overfly this convection. The square spiral pattern was terminated after one complete box around Frank, and the Global Hawk flew four northwest-southeast legs across the low level circulation center and the convective region.  We missed the peak of the convection so we did not catch very much heavy rain on any of these passes.  HAMSR saw some convection on the earlier legs.  The flight produced spectacular pictures of the low level circulation from the HDVIS camera.  The flight was great for the first time out and it allowed all the scientists, flight, and ground crew to figure out how to make this plane work for hurricane research.  

Dropsondes were not ready or approved for this flight so the instrument flew but no sondes were launched.  HAMSR and LIP performed nominally; there was virtually no lightning with this system so LIP did not capture anything interesting.  HIWRAP had startup issues during the first hour of flight due to a damaged connector on an ethernet hub that discovered just before flight; the the hub started working so the system functioned after that.