GRIP Flights Focusing on Tropical Storm Gaston
Visible imageshows the remnant clouds from what was Tropical Depression Gaston over the Leeward Islands.This visible image from the GOES-13 satellite at mid-day Sept. 7, 2010, shows the remnant clouds from what was Tropical Depression Gaston over the Leeward Islands and northeastern Caribbean Sea. (NOAA/NASA GOES Project) NASA aircraft carrying specialized weather instruments are continuing to monitor tropical storms and potential hurricanes in the Atlantic Ocean as part of the agency's Genesis and Rapid Intensification Processes mission, or GRIP, which continues through Sept. 25. GRIP is designed to help improve our understanding of how hurricanes such as Earl form and intensify rapidly.

After numerous flights by NASA's DC-8 flying science laboratory and Global Hawk remotely operated aircraft over Hurricane Earl as it swept up the eastern seaboard last week, scientists aboard the DC-8 turned their attention to Tropical Storm Gaston over the Labor Day weekend.

On Sunday Sept. 5, The DC-8 flew from its deployment base at Ft. Lauderdale to St. Croix in the Virgin Islands. Scientists aboard the converted jetliner used suite of instruments to sample atmospheric dust layers and calibrate instruments during the three-hour flight.

The following day, the DC-8 flew a 7.4-hour mission from St. Croix over the Gaston system, now downgraded to a tropical depression. Sixteen dropsondes were launched while the aircraft flew a box spiral and butterfly pattern over Gaston.

Another data-collection flight on Tuesday, Sept. 7, saw the DC-8 conduct an octagonal perimeter survey over the same storm, and then flew over its center, according to mission manager Bob Curry, director of Science Missions for NASA's Dryden Flight Research Center. After launching 19 dropsondes over the east and west sides and the central region of Gaston, the flying science lab conducted various maneuvers to aid the scientists on board in their data collection efforts as it headed back to Ft. Lauderdale..

NASA�s DC-8 flew to Hurricane Earl four times in the past week to collect data as Earl both strengthened and weakened.NASA’s DC-8 flew to Hurricane Earl four times in the past week to collect data as the storm both strengthened and weakened. This image shows one of the DC-8’s passes through the eye of Earl on Aug. 30. NASA’s Genesis and Rapid Intensification Processes (GRIP) experiment was designed to collect new data on how hurricanes form and how they strengthen and weaken, which remain elusive questions for hurricane scientists. Credit: NASA/Jane Peterson At mid-day Sept. 7, Gaston's remnants were located over the Leeward Islands and the northeastern Caribbean Sea, and the National Hurricane Center gave Gaston only a 10 percent chance of rebuilding into a major storm over the next 48 hours.

On Sept. 2, NASA's Global Hawk flew a 24-hour mission from its Southern California base, amassing about 10 hours of data-collection passes over Hurricane Earl, much of it in coordination with the DC-8. While the Global Hawk monitored the hurricane from about 60,000 feet altitude, the DC-8 flew a three-leaf clover pattern with five passes through the eye at about 35,000 feet while scientists launched 35 dropsondes and recorded data on the storm's progress and intensity.

"The success of this mission is hard to comprehend," related NASA Dryden's Global Hawk project manager Chris Naftel after the craft returned to Edwards Air Force Base. "We crossed the eye of Hurricane Earl seven times and made two other passes near the eye. Twice we coordinated eye crossings at the same time as the DC-8, which was flying about 25,000 feet below the Global Hawk. The scientists are overjoyed with the data they were able to collect."

The Global Hawk is not expected to fly another mission in the GRIP campaign until at least Friday, Sept. 10. In the meantime, engineers and technicians for the National Center for Atmospheric Research are working on a fix to NCAR's autonomous dropsonde deployment system that failed during a check flight in late August. All other instruments on the aircraft are functioning properly.

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