NASA's Global Hawk Completes Second GloPac Science Flight
NASA's Global Hawk environmental science aircraft took to the skies again April 13 on the second flight in the 2010 Global Hawk Pacific (GloPac) atmospheric sampling mission. Lasting more than 24 hours and covering almost 9,000 miles, the flight left NASA's Dryden Flight Research Center at Edwards Air Force Base shortly before 7 a.m. Tuesday and returned at 7:12 a.m. Wednesday morning April 14.
According to NASA Dryden's Global Hawk project manager Chris Naftel, the second data-collection flight in the series took the autonomously operated aircraft along a pre-programmed flight path over the Pacific Ocean to just south of Alaska, then southward to just east of Hawaii to about 15 degrees north latitude, and then eastward back to North America with a final northbound leg back to Edwards in Southern California. The mission reached a maximum altitude of 62,000 feet and included two planned data-collection descents from 59,000 to 43,000 feet as it explored the atmosphere at latitudes between 52 degrees north in the Arctic and 12 degrees north in the tropics.
GloPac researchers are measuring and sampling greenhouse gases, ozone-depleting substances, aerosols, and constituents of air quality in the upper troposphere and lower stratosphere. Because of the Global Hawk's long endurance, the GloPac measurements cover longer time periods and greater geographic distances than can be achieved with any other science aircraft.
During the long southbound leg over the Pacific, the Global Hawk flew under the tracks of two of NASA's "A-train" satellites – Aura and CALIPSO – while a Gulfstream V aircraft operated by the National Center for Atmospheric Research flew the same track at a much lower altitude. All three air- or space-borne platforms collected data at the same time, with data from the science instruments aboard the aircraft used verify data obtained by the satellites.
Atmospheric physicist Paul Newman, co-mission scientist for GloPac, said one of the goals of the flight was to obtain air samples from fragments of the polar vortex as the dominant wintertime weather and wind pattern in the Arctic starts to break up during spring. Newman said mission scientists also hoped to obtain samples of a large dust plume coming across Pacific from Asia.
On the eastbound leg along the 15-degree latitude, scientists sampled very cold air at temperatures as low as minus 100 degrees Celsius in the stratosphere above the tropics.
The first science data-collection flight in the GloPac mission April 7 took NASA's Global Hawk over the Pacific Ocean and then up toward the Aleutians before it turned back. That 14-hour flight, covering more than 4,500 nautical miles at altitudes up to 61,000 feet, was the first of five scheduled for the GloPac mission to study atmospheric science over the Pacific and Arctic oceans.