Operation IceBridge is an ongoing

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

mission to monitor changes in

polar ice A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice. There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor a ...

. It is an airborne follow-on mission to the

ICESat ICESat (Ice, Cloud, and land Elevation Satellite) was a NASA satellite mission for measuring ice sheet mass balance, cloud and aerosol heights, as well as land topography and vegetation characteristics. It operated as part of NASA's Earth Obs ...

satellite, continuing until after the

ICESat-2 ICESat-2 (Ice, Cloud, and land Elevation Satellite 2), part of NASA's Earth Observing System, is a satellite mission for measuring ice sheet elevation and sea ice thickness, as well as land topography, vegetation characteristics, and clouds. ICES ...

mission launch in September 2018.

Program history

From 2003 to 2009,

used a space-based laser altimeter, ICESat, for observing polar ice. ICESat was retired in 2009 due to a technical malfunction, leaving NASA without a satellite dedicated to ice observance. A next-generation satellite, ICESat-2, launched in September 2018. In order to maintain annual observations of ice sheets and sea ice, NASA introduced the IceBridge program to "bridge the gap" between satellite missions. The program utilizes aircraft platforms to make airborne measurements of the polar regions. IceBridge flights began in March 2009, on an Arctic Spring campaign based out of

Thule Air Base Thule Air Base (pronounced or , kl, Qaanaaq Mitarfik, da, Thule Lufthavn), or Thule Air Base/Pituffik Airport , is the United States Space Force's northernmost base, and the northernmost installation of the U.S. Armed Forces, located north o ...

, Greenland. Southern Hemisphere flights began during the first Austral Spring campaign in October 2009, based out of

Punta Arenas Punta Arenas (; historically Sandy Point in English) is the capital city of Chile's southernmost region, Magallanes and Antarctica Chilena. The city was officially renamed as Magallanes in 1927, but in 1938 it was changed back to "Punta Aren ...

, Chile. Flights during field campaigns can contain either dedicated land ice and

sea ice Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oce ...

flights, or a combination thereof, based upon platform, weather and location constraints. To date there have been Spring campaigns in the Arctic and Antarctic, as well as flights monitoring summer melt on Alaskan glaciers every year since 2009. Additional campaigns have occurred in the Arctic summer and East Antarctica.

Platforms

IceBridge flights began in March 2009 using a

Lockheed P-3 Orion The Lockheed P-3 Orion is a four-engined, turboprop anti-submarine and maritime surveillance aircraft developed for the United States Navy and introduced in the 1960s. Lockheed based it on the L-188 Electra commercial airliner.time series In mathematics, a time series is a series of data points indexed (or listed or graphed) in time order. Most commonly, a time series is a sequence taken at successive equally spaced points in time. Thus it is a sequence of discrete-time data. Exa ...

of changes in elevation. This instrument works similarly to the

lidar Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. It can also be ...

instrument used in ICESat and is helping maintain a record of elevation changes until ICESat-2 becomes operational. Land Vegetation and Ice Sensor (LVIS) - The Land, Vegetation and Ice Sensor (LVIS) is a laser altimeter optimized for operation at higher altitudes. LVIS was created by scientists at the Laser Remote Sensing Laboratory at NASA's Goddard Space Flight Center. LVIS has flown on a wide variety of aircraft such as NASA's P-3, DC-8, B-200 and HU-25C Guardian Falcon and NSF's Gulfstream G-V. By flying at a higher altitude, LVIS can survey larger areas and expands IceBridge's range.

Radars

Operation IceBridge uses up to four different radar instruments operated by the Center for the Remote Sensing of Ice Sheets (CReSIS) at the

University of Kansas The University of Kansas (KU) is a public research university with its main campus in Lawrence, Kansas, United States, and several satellite campuses, research and educational centers, medical centers, and classes across the state of Kansas. Tw ...

Indiana University Indiana University (IU) is a system of public universities in the U.S. state of Indiana. Campuses Indiana University has two core campuses, five regional campuses, and two regional centers under the administration of IUPUI. *Indiana Universit ...

provides

data management Data management comprises all disciplines related to handling data as a valuable resource. Concept The concept of data management arose in the 1980s as technology moved from sequential processing (first punched cards, then magnetic tape) to r ...

services for CReSIS activities in Operation IceBridge. Multichannel Coherent Radar Depth Sounder (MCoRDS) - The Multichannel Coherent Radar Depth Sounder (MCoRDS) is used to measure ice thickness and map beneath the ice. This instrument uses multiple channels and a large range of radar frequencies to image internal ice layering and bedrock beneath ice sheets. Information on sub-ice terrain is useful for modeling ice sheets. Snow Radar - The CReSIS Snow Radar instrument is used to measure the thickness of snow layers on top of land and sea ice. Measuring snow thickness is crucial for estimating sea ice thickness. Ku-band Radar Altimeter - IceBridge also carries a

Ku band The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally german: Kurz-unten), because it is the lower part of the ori ...

radar altimeter, which can penetrate snow layers to measure sea and land ice surface elevation. Accumulation Radar - The accumulation radar instrument is used to gather high-resolution data on the top part of ice. Looking at the uppermost part of ice allows researchers to map past snow accumulation rates.

Mapping instruments

Digital Mapping System (DMS) - The Digital Mapping System (DMS), created by researchers at NASA's Ames Research Center, is an airborne digital imaging system that is used to detect openings in sea ice and build high-resolution maps of polar ice. The DMS instrument is a downward-facing digital camera that captures multiple individual frames that are combined into image mosaics using computer software. Gravimeter - Operation IceBridge also uses a gravity-measuring instrument known as a

gravimeter Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of a gravitational field or the properties of matter responsible for its creation are of interest. Units of measurement Gr ...

. This instrument measures the strength of gravitational fields beneath the aircraft, which researchers can use to determine the shape of water cavities beneath floating ice shelves. Because water is less dense than rock, areas of floating ice show weaker gravitational fields than areas with rock underneath. Magnetometer - The NASA

P-3 Orion The Lockheed P-3 Orion is a four-engined, turboprop anti-submarine and maritime surveillance aircraft developed for the United States Navy and introduced in the 1960s. Lockheed based it on the L-188 Electra commercial airliner.glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

and sea ice.

Pine Island Glacier Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine ...

is one such area of focus. There, Operation IceBridge has been observing the underside of the ice-sheet using an advanced radar, as well as closely monitoring an area of Pine Island Glacier known as the ice tongue that, were it to melt, would allow a large portion of the glacier to slide into the Amundsen Sea. In August 2013 the discovery of the longest canyon on Earth under the Greenland ice sheet was reported, based on an analysis of data from Operation IceBridge.

Outreach and collaborations

References

External links

Operation IceBridge
at NASA.gov
Antarctic Bedrock: Visualizations
at NASA.gov * {{cite news , url=https://www.nasa.gov/topics/earth/features/antarctic-map.html , title=NASA's IceBridge Mission Contributes to New Map of Antarctica , publisher=NASA , date=4 June 2013 NASA programs 21st century in the Arctic Arctic research Science and technology in Antarctica United States Antarctic Program Geology of Antarctica 2009 establishments in Antarctica 2009 establishments in the United States Articles containing video clips Earth observation projects