NASA's Hurricane Severe Storms Sentinel (HS3) Mission is in full-swing and one of the unmanned Global Hawk aircraft investigate Tropical Storm Nadine on Sept. 14 and 15, while NASA satellites continued to obtain imagery of the storm as seen from space.
The Moderate Resolution Imaging Spectroradiometer aboard NASA's Terra satellite captured a true-color image of Hurricane Nadine in the Atlantic Ocean on Sept. 16 at 1345 UTC (9:45 a.m. EDT) while NASA's Global Hawk was flying around the storm. Nadine strengthened to a hurricane on Friday, Sept. 14 at 11 p.m. EDT, and weakened back to a tropical storm on Sunday, Sept. 16 at 11 p.m. EDT. Nadine's highest wind speed as a hurricane was 80 mph (130 kmh).
NASA's Global Hawk landed back at the Wallops Flight Facility, Wallops Island, Va., in the morning hours on Sept. 15 after spending a full day gathering data from Hurricane Nadine. "During the flight, Nadine strengthened from a tropical storm to a hurricane despite being hit by very strong westerly winds at upper levels and very dry air on its periphery," said Scott Braun, HS3 Mission Principal Investigator from NASA's Goddard Space Flight Center, Greenbelt, Md. Data from this flight will help scientists determine how a storm like Nadine can intensify even in the presence of seemingly adverse conditions. Nadine is currently a tropical storm.
"The Global Hawk, one of two associated with the HS3 mission, sought to determine how the structure of Nadine might change under the influence of strong vertical wind shear as it moved northward in the Atlantic, " Braun said. During its 22.5 hour flight around Nadine, the Global Hawk covered more than one million square kilometers (386,100 square miles) going back and forth over the storm in what's called a "lawnmower pattern." The Global Hawk captured data using instruments aboard and also dropping sensors called sondes into the storm. The dropsonde system ejected the small sensors tied to parachutes that drift down through the storm measuring winds, temperature and humidity.
At 11 a.m. EDT) on Sept. 17, Tropical Storm Nadine had maximum sustained winds near 70 mph (100 kmh). It was located about 585 miles southwest of the Azores, near 32.9 North and 35.3 East. Nadine is moving to the northeast near 15 mph (24 kmh). The National Hurricane Center forecasts some weakening in the next day.