Hurricane Earl's eye, as measured by NASA's HAMSR intrument on Sept. 2, 2010. The data reflect the brightness temperatures of the storm with cooler temperatures in shades of blue and green and warmer temperatures in oranges and reds. The pink crosses represent lightning. Image credit: NASA-JPL/Data SIC/NOAA/U.S. Navy/NGA/GEBCO/Google
› Larger view NASA's remotely operated Global Hawk environmental science aircraft returned to Edwards Air Force Base in Southern California late Thursday evening Sept. 2 after a more than 24-hour mission to track the path and intensity of Hurricane Earl off the east coast of the United States.
The flight was flown in coordination with NASA's DC-8 flying science laboratory over the hurricane, both of which made repeated passes over Earl. The flights were part of the aerospace agency's Genesis and Rapid Intensification Processes, or GRIP, hurricane research campaign.
Earl's intensity was downgraded to a Category 2 hurricane Friday morning as its maximum winds dropped below 115 mph as it sideswiped the outer banks of the Carolinas and Virginia and turned more toward the northeast. As of mid-day Friday, it was still considered a threat to outer Long Island, Nantucket, Cape Cod and the east coast of Maine along New England coastline.
The high-altitude Global Hawk had departed NASA's Dryden Flight Research Center at Edwards shortly before 9 p.m. PDT Wednesday evening, and touched down just after 9 p.m. PDT Thursday. After a seven-hour cross-country transit, the Global Hawk overflew the hurricane eight times in nine hours while its suite of three advanced weather instruments monitored the storm's characteristics. Data from the instruments were then transmitted via Satcom links to the aircraft's operations center at NASA Dryden.
› More on the Global Hawk's weather instruments
Hurricane Earl, as seen from a high-definition camera aboard NASA's Global Hawk uninhabited aerial vehicle on Sept. 2. Image credit: NASA-JPL/DFRC
› Larger view
While the unmanned aircraft was making repeated passes over the eye of Earl at altitudes in the 60,000-foot range, the DC-8 flew coordinated passes at altitudes of 35,000 to 40,000 feet while scientists aboard the converted jetliner collected data from its suite of nine instruments to characterize the powerful storm. Based at the Dryden Aircraft Operations Facility in Palmdale, Calif., The DC-8 is currently deployed to Ft. Lauderdale, Fla., for the GRIP research mission.
The Global Hawk was not scheduled to fly over the Labor Day weekend, but the DC-8 completed two data-collection flights from Ft. Lauderdale and St. Croix Sept. 5 and 6, with another missions scheduled Sept. 7.
NASA's WB-57 weather reconnaissance aircraft, based at the Johnson Space Center's Ellington Field near Houston, is currently deployed to Tampa, Fla., and was also scheduled to overfly Hurricane Earl.
The flights by the NASA science aircraft are in close support of operations being flown by four aircraft operated by the National Oceanic and Atmospheric Administration and the National Science Foundation that are also involved in the six-week GRIP campaign.
› Read more on GRIP Mission
› Dryden News Photos