An ultra-wideband, microwave radar for measuring snow thickness on sea ice and mapping near-surface internal layers in polar firn

• Published in: Journal of Glaciology
• Main Authors: Panzer, Ben, Gomez-Garcia, Daniel, Leuschen, Carl J., Paden, John D., Rodriguez-Morales, Fernando, Patel, Aqsa, Markus, Thorsten, Holt, Benjamin, Gogineni, Sivaprasad
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: International Glaciological Society 2015
• Subjects: Antarctic; Arctic; The Antarctic; Antarc*; Center for Remote Sensing of Ice Sheets (CReSIS); Climate change; Journal of Glaciology; Sea ice
• Online Access: http://hdl.handle.net/1808/18760; https://doi.org/10.3189/2013JoG12J128

This is the published version. Copyright 2013 International Glaciological Society Sea ice is generally covered with snow, which can vary in thickness from a few centimeters to >1 m. Snow cover acts as a thermal insulator modulating the heat exchange between the ocean and the atmosphere, and it impacts sea-ice growth rates and overall thickness, a key indicator of climate change in polar regions. Snow depth is required to estimate sea-ice thickness using freeboard measurements made with satellite altimeters. The snow cover also acts as a mechanical load that depresses ice freeboard (snow and ice above sea level). Freeboard depression can result in flooding of the snow/ice interface and the formation of a thick slush layer, particularly in the Antarctic sea-ice cover. The Center for Remote Sensing of Ice Sheets (CReSIS) has developed an ultra-wideband, microwave radar capable of operation on long-endurance aircraft to characterize the thickness of snow over sea ice. The low-power, 100mW signal is swept from 2 to 8GHz allowing the air/snow and snow/ ice interfaces to be mapped with 5 cm range resolution in snow; this is an improvement over the original system that worked from 2 to 6.5 GHz. From 2009 to 2012, CReSIS successfully operated the radar on the NASA P-3B and DC-8 aircraft to collect data on snow-covered sea ice in the Arctic and Antarctic for NASA Operation IceBridge. The radar was found capable of snow depth retrievals ranging from 10cm to >1 m. We also demonstrated that this radar can be used to map near-surface internal layers in polar firn with fine range resolution. Here we describe the instrument design, characteristics and performance of the radar.