Operation IceBridge

Operation IceBridge
Name	Operation IceBridge
Caption	A NASA P-3B aircraft during a survey flight over Antarctica.
Organization	NASA / Goddard Space Flight Center
Location	Arctic and Antarctica
Duration	2009 – 2019 (primary)
Website	https://www.nasa.gov/mission_pages/icebridge/index.html

Operation IceBridge. It was a NASA-led airborne mission designed to monitor Earth's polar ice sheets, glaciers, and sea ice, bridging the observational gap between two satellite missions. Conducted primarily from 2009 to 2019, the project utilized instrumented aircraft to collect critical data on ice thickness, bedrock topography, and snow accumulation. This extensive campaign provided an unprecedented, multi-year record of rapidly changing cryospheric regions, informing models of sea level rise and climate change.

Overview

Initiated following the loss of contact with the ICESat satellite in 2009, the mission was managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland. Annual campaigns were flown over Greenland and Antarctica, with additional surveys in Alaska, Canada, and Patagonia. The operation served as a direct precursor and validation source for the subsequent ICESat-2 mission, ensuring continuity in a vital climate data record. Its decade of flights created a foundational dataset for the international scientific community studying the polar regions.

Mission and objectives

The primary objective was to quantify changes in the mass balance of the Greenland ice sheet and Antarctic ice sheet using a suite of remote sensing instruments. Key goals included measuring annual ice elevation changes, mapping bedrock beneath glaciers like Thwaites Glacier, and assessing the thickness of Arctic sea ice. Scientists from institutions like the University of Kansas and the Lamont–Doherty Earth Observatory used the data to study ice sheet dynamics and improve predictions for the Intergovernmental Panel on Climate Change (IPCC) reports. The mission also aimed to identify previously unknown features, such as subglacial lakes and canyons.

Instrumentation and aircraft

The mission employed several aircraft, most notably a P-3B turboprop and a DC-8 jet, outfitted with an array of instruments. The core instrument was a laser altimeter system, the Airborne Topographic Mapper (ATM), which precisely measured surface elevation. A radar sounder, the Multichannel Coherent Radar Depth Sounder (MCoRDS) developed by the University of Kansas, penetrated ice to map bedrock. Other key tools included a gravimeter for mapping seafloor bathymetry, a magnetometer, and digital mapping cameras like the Digital Mapping System (DMS). Flights often originated from bases like Thule Air Base in Greenland and McMurdo Station in Antarctica.

Key findings and scientific contributions

Data revealed accelerating ice loss from major outlets like Jakobshavn Glacier and detailed the vulnerable underpinnings of the West Antarctic Ice Sheet. It documented the rapid thinning of Arctic sea ice and discovered a massive, previously hidden canyon beneath the Greenland ice sheet. These observations were published in leading journals such as *Science* and *Nature*, directly contributing to our understanding of glacial isostatic adjustment and ocean-driven melting. The mission also provided critical validation data for European Space Agency satellites like CryoSat-2.

Relationship to ICESat missions

The operation was explicitly conceived to fill the data gap between the original ICESat mission, which ended in 2009, and its successor, ICESat-2, launched in 2018. It extended the time series of ice sheet elevation changes initiated by ICESat, using similar laser altimetry techniques but with higher spatial resolution from aircraft. This bridge ensured no loss in the critical climate record and allowed for cross-calibration between the satellite sensors. Data from the airborne campaigns were essential for refining the algorithms and performance expectations for the Advanced Topographic Laser Altimeter System (ATLAS) on ICESat-2.

Legacy and conclusion

The mission concluded its primary airborne campaigns in 2019 following the successful launch and checkout of ICESat-2. Its legacy endures in a vast, open-access archive of data that continues to fuel new discoveries about polar processes and global warming. The program demonstrated the powerful synergy between sustained airborne surveys and satellite observations for Earth system science. Insights gained directly influence ongoing international research efforts, such as those by the British Antarctic Survey and the Alfred Wegener Institute, and will inform climate policy for decades.

Category:NASA programs Category:Climate change assessment and attribution Category:Arctic research Category:Antarctic research