NASA - National Aeronautics and Space Administration

NASA's DC-8 airborne science laboratory has returned to its base after completing the six-week GCPEx snowfall precipitation mission in eastern Canada. (NASA / Tony Landis) › View Larger Image

The snow-covered city of Barrie, Ontario, Canada, surrounds ice-bound Lake Simcoe in this view from NASA's DC-8 airborne science laboratory during a flight Feb. 20 in NASA's Global Precipitation Measurement Cold-season Precipitation Experiment, or GCPEx, mission. (NASA / Joe Munchak) › View Larger Image NASA's DC-8 airborne science laboratory has returned to its home base in Palmdale, Calif., after completing 13 data-collection flights over the past six weeks during NASA's Global Precipitation Measurement Cold-season Precipitation Experiment, or GCPEx, snow study over Ontario, Canada.

The converted jetliner returned to its home hangar at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., Feb. 25, after a six-hour flight from Bangor, Maine. The aircraft flew almost 80 hours during its 13 science flights in the mission.

"The GCPEx mission has been a real success," said Walter Petersen, the Global Precipitation Measurement ground validation scientist at NASA's Wallops Flight Facility in Virginia. "The majority of the mission objectives were accomplished, especially as they pertain to collecting a broad spectrum of snowfall, mixed phase, and even rain precipitation events.

"All indications are that the airborne and ground-based instruments worked very well, meaning we expect to have a robust set of data to analyze toward supporting the development of GPM falling-snow retrieval algorithms," Peterson added.

Air Force pilot / navigator Greg Schaeffer and NASA research pilot Dick Ewers guide NASA's DC-8 flying laboratory toward landing at Bangor International Airport, Maine, following a science flight in NASA's Global Precipitation Measurement Cold-season Precipitation Experiment, or GCPEx, snow study over Ontario, Canada. (NASA / Joe Munchak) › View Larger Image The last science mission Feb. 24, was a 6.8-hour flight over a storm system in the Boston area, followed by multiple passes over the Environment Centre for Atmospheric Research Experiments, or CARE, location in Egbert, Ontario, and atmospheric convection over Lake Ontario. Data on various types of precipitation was collected by the two primary instruments used for this experiment, the APR-2 Airborne Precipitation Radar and the Conical Scanning Millimeter-wave Imaging Radiometer, or CoSMIR.

A prior five-hour flight Feb. 21 targeted the CARE area. Additional passes over Lake Ontario captured good mixed snow and rain data. The previous day, a four-hour flight was flown in clear air over the CARE site for CoSMIR calibration.

The goal of the GCPEx field experiment was to help scientists match measurements of snow in the air and on the ground with measurements to be taken by the Global Precipitation Measurement satellite, due to launch in 2014.

In addition to CARE's ground network of snow gauges and sensors and measurements from aircraft, advanced ground radars scanned the entire air column from the clouds to the Earth's surface.

During GCPEx, the DC-8 flew above the clouds as a Cessna Citation from the University of North Dakota and a Convair 580 from the Canadian National Research Council flew through the clouds while their specialized meteorological instruments measured the microphysical properties of the raindrops and snowflakes inside.

For more information about GCPEx, visit:
Beth Hagenauer, public affairs
NASA Dryden Flight Research Center