In 2009, NASA started conducting the largest airborne survey of Earth's polar ice under Operation IceBridge to bridge the observational gap between ICESat and ICESat-2

In 2009, NASA started conducting the largest airborne survey of Earth's polar ice under the mission Operation IceBridge to bridge the observational gap between the ICESat and ICESat-2 satellite missions. The program was created to continue measurements of Earth's polar regions when ICESat was no longer providing the same satellite observations and before ICESat-2 began its mission. Operation IceBridge used aircraft to collect measurements over areas that included Greenland, Antarctica, the Arctic and Alaskan glaciers. The program focused on changes in sea ice, ice sheets and glaciers. These observations helped scientists study how polar ice changes over time and improve models used to understand sea-level rise.

Operation IceBridge filled a gap between two satellite missions

Operation IceBridge was designed around the period between NASA's ICESat and ICESat-2 missions. ICESat had provided measurements of ice elevation, while ICESat-2 was developed to continue and improve those observations.


The airborne campaign allowed scientists to continue collecting information during this gap. Aircraft could fly over selected areas and carry instruments that measured the ice surface, snow and conditions below the ice.

The supplied mission information describes the survey as running from 2009 to 2020. NASA's mission timeline also identifies November 20, 2019, as the date of the final polar flight. The broader program material lists airborne campaigns from 2009 to 2021. These dates reflect different descriptions of the campaign and program period, while the final polar flight took place in November 2019.

The first flights began in 2009. Flights over Greenland took place in March and May, while flights over Antarctica were conducted in October and November. The main purpose was to maintain a record of polar ice elevation and thickness during the transition between satellite missions.

Aircraft carried instruments to study ice

Operation IceBridge depended on aircraft that could carry several scientific instruments during the same flight. The research fleet included NASA's DC-8 and P-3 Orion. These aircraft carried laser altimeters, radar systems and cameras. Each instrument was used to collect a different type of information.

Laser altimeters measured the elevation of the ice surface. One of the systems used by IceBridge was the Airborne Topographic Mapper, also known as ATM. Radar systems provided information below the ice surface. Ice-penetrating radar was used to study the shape of the bedrock beneath ice sheets. Snow radar helped scientists measure snow depth.

The mission also used imaging systems. These systems collected visible, hyperspectral and infrared images. The images provided information about the condition and structure of ice and the surrounding areas. The combination of these instruments allowed researchers to connect surface measurements with information about snow, ice thickness, bedrock and other properties.

In 2009, NASA started conducting the largest airborne survey of Earth's polar ice under Operation IceBridge

The program had several objectives. One was to extend and improve the record of measurements that began with ICESat. Another was to connect measurements from different systems so scientists could compare observations across time.

IceBridge measurements could be compared with data from historical airborne laser altimeters, ICESat, ICESat-2 and the European Space Agency's CryoSat-2 mission. This helped scientists build a longer record of ice elevation measurements.

The campaign also focused on areas where ice was changing quickly. Regular observations helped maintain records of changes in the Arctic and Antarctic. The data were used to improve understanding of ice dynamics. Scientists could also use the information to improve models that predict sea-level rise and changes in sea ice cover.

What scientists wanted to measure?

One science goal was to document changes in the volume of Greenland and Antarctic ice sheets during the period between ICESat and ICESat-2. Researchers gave attention to areas where rapid changes were taking place. Measuring these changes helped scientists understand how ice sheets respond to changes in their surroundings.

The program also studied glacier and ice-shelf thickness. It collected information about ice-shelf bathymetry, snow accumulation rates and other geophysical properties. These measurements helped scientists interpret changes detected through laser altimetry. They also provided information for computer models that simulate ice-sheet flow and mass balance.

Another goal was to document changes in average sea ice thickness in the Arctic and Southern Oceans. Scientists could use the information for climate studies and assessments. IceBridge also worked on improving methods for measuring sea ice thickness. Researchers studied surface elevation, freeboard and snow depth over sea ice.

Key objectives included:

• Extending measurements that began with ICESat.
• Linking historical airborne measurements with ICESat, ICESat-2 and CryoSat-2 data.
• Monitoring areas where Arctic and Antarctic ice was changing.
• Measuring changes in ice-sheet volume.
• Studying glacier and ice-shelf thickness.
• Measuring snow depth and accumulation.
• Tracking changes in sea ice thickness.
• Improving sea ice thickness measurement methods.
• Providing data for sea-level rise models.

IceBridge recorded changes across Greenland and Antarctica

The airborne survey produced several findings during its years of operation. One discovery was a massive canyon beneath Greenland's ice sheet. The canyon stretches for about 400 miles. IceBridge measurements helped researchers identify the feature below the ice. The campaign also documented cracks and rifts in Antarctic ice. One observation involved a crack about 19 miles long in Pine Island Glacier.

IceBridge also contributed to the identification of a major impact crater beneath Greenland's Hiawatha Glacier. The finding provided another example of how measurements collected from aircraft can reveal features hidden beneath ice. The program did not only focus on discoveries. A major part of its work was the creation of datasets that could be used by scientists studying polar regions.

The data became part of long-term climate research

Operation IceBridge generated measurements that could be used with satellite and historical datasets. This helped researchers compare changes across different years. The information also contributed to topographic models. One example is BedMachine and related datasets, while the supplied material specifically identifies BedMap2 as a model that received contributions from IceBridge data.

The campaign's data supported more than 660 scientific publications, according to the supplied information. This research helped scientists study the connection between polar ice and the global climate system. Changes in glaciers, ice sheets and sea ice can affect the Earth's climate system and contribute to changes in sea level.

Why the mission matters?

Polar ice measurements are important because ice does not remain unchanged. Ice sheets can lose or gain mass, glaciers can change thickness and sea ice can change in extent and thickness.

Satellite missions provide measurements over large areas. Aircraft can complement those observations by carrying instruments that collect measurements at specific locations and at different levels of detail.

IceBridge therefore served as a link between satellite observations. Its measurements helped maintain continuity during the transition from ICESat to ICESat-2. The program also created records that can be compared with later observations. This makes the data useful beyond the individual flights.

For scientists, long-term records are important because they help separate short-term changes from longer patterns. The measurements can also improve models used to study future ice conditions and sea-level rise.

What Operation IceBridge achieved?

Operation IceBridge brought together aircraft, laser altimeters, radar and imaging systems to study Earth's polar ice. Its work covered Greenland, Antarctica, the Arctic and Alaskan glaciers.

The mission tracked ice-sheet elevation, glacier thickness, sea ice thickness, snow depth and conditions beneath the ice. It also recorded changes in areas that were undergoing rapid transformation. Its findings included the canyon beneath Greenland, the impact crater beneath Hiawatha Glacier and changes in Antarctica's Pine Island Glacier.

The program also created a large body of scientific data. That information supported hundreds of scientific publications and contributed to models used to study the shape and structure of ice-covered regions.

Operation IceBridge shows how airborne research can support satellite missions. By continuing observations between ICESat and ICESat-2, the campaign helped scientists maintain a record of changes in Earth's polar regions and improve their understanding of processes connected to the global climate system and sea-level rise.