NASA’s Operation IceBridge is an airborne survey of polar ice. This year marks the eighth consecutive year that NASA aircraft have flown science flights over Arctic sea and land ice. NASA flies research flight over the Arctic in the spring and over the Antarctic in the fall.
The mission of Operation IceBridge is to collect data on changing polar land and sea ice and to maintain the continuity of measurements between NASA’s Ice, Cloud and Land Elevation Satellite (ICESat) missions. The original ICESat mission ended in 2009, and its successor, ICESat-2, is scheduled for launch in 2017. Operation IceBridge, which began in in 2009, is currently funded until 2019. The planned two-year overlap with ICESat-2 will help scientists validate the satellite’s measurements.
The extensive data IceBridge has gathered over the Greenland ice sheet during its six years of operations have provided an invaluable picture of the surface, the bed and the internal structures of Greenland’s ice sheet and it has allowed scientists to create more accurate models of the melting glaciers’ contribution to sea level rise. As for sea ice, IceBridge’s measurements of the thickness of sea ice and its snow cover have assisted in improving forecasts for summertime melt, enhanced the understanding of variations in ice thickness distribution from year to year, and updated the climatology of the snow depth over the sea ice.
Last year, the Arctic campaign was based in the Thule Air Base in northern Greenland and it also including a short deployment to Fairbanks, Alaska. The 2015 research focused on the sea ice in the Arctic Ocean north of Greenland and in the Beaufort and Chukchi Seas north of Alaska.
NASA is using two different types of venerable aircraft that have been totally retrofitted for the polar flights. Some of the flights are flown in Lockheed C-130 Hercules cargo aircraft retired by the US Air Force. C-130’s were the workhorses of the Vietnam War. NASA’s C-130 research aircraft fly to Thule Greenland from NASAs Wallops Flight Facility in Wallops Island, Virginia. Other flights are flown in Lockheed P-3 Orion aircraft, which the National Oceanic and Atmospheric Administration (NOAA) has used for years as hurricane hunters. They are based at MacDill Air Force Base in Florida.
I recent years climate scientists have noticed that the Arctic is losing more of its ice each summer, and the Operation IceBridge missions should help climate scientists study how sea ice melt is affecting Earth’s climate
The Operation IceBridge fleet of C-130 Hercules and P-3 Orion aircraft, which are are packed with scientific instruments, are flown through, above and below the clouds. Each of the planes has holes cut into the fuselage that allow for the placement of lasers, radiometers to measure radiation and other instruments that measure the thickness of sea ice.
NASA researchers will measure ice elevation using the LVIS laser altimeter and the LVIS-GH, a new, smaller version designed to fly on NASA’s Global Hawk unmanned aerial vehicle. LVIS and LVIS-GH will measure separate but overlapping swaths of the ice from an altitude of 28,000 feet.
According to Ben Smith, senior physicist at the University of Washington’s Advanced Physics Laboratory, Seattle, and a member of the science team that selected flight lines for this year’s IceBridge flights, “Surface melt is more than half of the story for Greenland’s mass loss. The rest of Greenland’s mass loss comes from ice flowing downhill into the ocean, often breaking off to form icebergs, and from melting at the base of the ice sheet.”
Warm summer temperatures lead to a decline in ice sheet elevation that often can be significant in low-lying areas along the Greenland coast. For example, in recent years the Jakobshavn Glacier, which is located in the lower elevations of western Greenland, has experienced ice sheet elevation declines of nearly 100 feet over a single summer. Higher elevations farther inland see less dramatic changes, usually only a few inches, and these changes are caused by pockets of air in the snowpack that shrink as temperatures rise.