New method to remotely sense ice sheet subsurface temperature demonstrated

September 12, 2017, NASA
UWBRAD instrument installed in the DC-3T aircraft. The cylinder in the foreground is the deployable "periscope" antenna, and the instrument electronics are housed in the rack in the background. Credit: Joel Johnson/OSU

A new instrument, the Ultrawideband Software-Defined Microwave Radiometer (UWBRAD), aims to provide measurements of ice sheet thermal emission to remotely sense internal ice sheet temperature information.

Physical temperature plays an important role in influencing stress-strain relationships in the volume, and therefore impacts ice sheet dynamics including deformation and flow across the ice sheet base. Previous studies and models have shown the potential of multi-frequency brightness temperature measurements to obtain deep ice sheet temperature information, given assumed ice sheet internal temperatures, electromagnetic permittivity, and other physical parameters such as density and particle grain size. UWBRAD is designed to provide brightness observations over the 0.5-2 GHz range, using multiple frequency channels and full-bandwidth sampling of each channel.

In November 2015, the UWBRAD team successfully demonstrated a four-channel prototype of the UWBRAD on a tower in Antarctica. This ground-based test successfully demonstrated that lower frequencies can sense internal ice sheet temperatures at depths of several kilometers and showed warmer temperatures with increasing depth. In 2016, the UWBRAD team applied the lessons learned from this previous ground-based prototype demonstration to a full 12-channel airborne instrument, which had its first test flights in September 2016 onboard a Kenn Borek Airlines DC-3T aircraft over Greenland and parts of Canada.

A view of the Canadian Rockies near the Columbia Icefield during the September 5, 2016 flight test. Credit: Joel Johnson/OSU

No methods currently exist for remotely sensing ice internal temperatures; presently, the only measured information is obtained from a small number of deep ice core sites. As an airborne instrument, UWBRAD could obtain this type of data over wide areas.

The 2016 airborne tests provided approximately 10 hours of the first ultrawideband microwave radiometer measurements of geophysical scenes including ice sheets. The UWBRAD project team intends to conduct additional flights to collect science data in early 2017.

Explore further: Study validates East Antarctic ice sheet to remain stable even if western ice sheet melts

Related Stories

Figuring out how fast Greenland is melting

July 5, 2017

A new analysis of Greenland's past temperatures will help scientists figure out how fast the island's vast ice sheet is melting, according to a new report from University of Arizona atmospheric scientists.

NASA maps thawed areas under Greenland ice sheet

August 4, 2016

NASA researchers have helped produce the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed—key information in better predicting how the ice sheet will react to a warming climate.

Greenland sets record temperatures, ice melts early

September 13, 2016

Temperature records were broken in Greenland this year after parts of the territory's vast ice sheet began melting unusually early, the Danish Meteorological Institute (DMI) said Tuesday.

Recommended for you

Cities as study proxies for climate change

July 18, 2018

Cities can serve as useful proxies to study and predict the effects of climate change, according to a North Carolina State University research review that tracks urbanization's effects on plant and insect species.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.