Two NASA environmental research aircraft – a DC-8 flying science laboratory and an unmanned long-endurance Global Hawk – completed coordinated science flights over the AL-92 tropical disturbance southeast of Haiti and the Dominican Republic in the Caribbean Sept. 12, with a follow-up flight by the DC-8 over the same storm system Sept. 13. The flights were part of NASA's six-week Genesis and Rapid Intensification Processes, or GRIP, mission that is studying how and why some tropical storms rapidly intensify into hurricanes while others diminish just as rapidly.
All nine instruments installed on the DC-8 collected data during its Sunday flight over the storm system, and 21 dropsondes were launched successfully to aid the other instruments in gauging wind profiles and moisture content. After some early difficulties were resolved in flight path coordination with the Global Hawk flying some 20,000 feet above, both aircraft flew two coordinated data-collection passes over the storm at the same time. The passes were also coordinated with a Gulfstream IV operated by the National Oceanic and Atmospheric Administration in the same area.
The Global Hawk, operated remotely from NASA's Dryden Flight Research Center at Edwards Air Force Base in Southern California, completed a 24.3-hour flight, including seven hours collecting data over the storm system itself, according to payload engineer Dave Fratello at Dryden. The aircraft had departed Edwards at 4:30 a.m. PDT Sunday, and landed at 4:50 a.m. Monday, Sept. 13. Mission scientists are downloading data recorded during the flight from the three specialized meteorological instruments installed on the Global Hawk for the GRIP campaign.
During its follow-up 8.5-hour flight over the storm system on Monday, the DC-8 completed four transects of the center of the system with all nine instruments operating, including the deployment of another 21 dropsondes. The modified jetliner conducted various maneuvers at 32,000 ft. altitude during which the Meteorological Measurement System in the aircraft's nose recorded barometric pressure, temperature, winds and turbulence before the aircraft returning to its deployment base at Fort Lauderdale, Fla.