IceBird ice thickness surveys carried out with the Polar 5 and Polar 6 aircraft between 2009 and 2017.
Objectives
The AWI IceBird program is a series of airborne surveys to collect measurements of sea ice thickness in the Arctic conducted by the Alfred Wegener Institute for Polar and Marine Research (AWI). Airborne surveys provide insight into composition and properties of the ice in general and how it changes over time. IceBird’s ice thickness measurements use a tethered electromagnetic sensor, the EM-Bird, towed by research aircraft 50 feet/ 15 m above the ice surface. The AWI IceBird campaigns take place twice a year: In summer (August) and winter (March/April), when sea ice extent and thickness are at their minimum and maximum, respectively. To cover large distances over sea ice, we operate the research aircraft Polar 5 and Polar 6 from the following bases:
Longyearbyen, Svalbard, Norway
Station Nord, North-East Greenland
CFSAlert, Canada
Eureka weather station, Canada
Resolute Bay, Canada
Inuvik, Canada
Barrow, US
IceBird is a continuation of earlier campaigns (TIFAX, PAMARCMIP) made north of Svalbard, Greenland, and Canada. IceBird campaigns are frequently carried out in close collaboration with other projects, e.g. with the European Space Agency’s Cryosat Validation Experiments (CryoVEx) and NASA’s Operation Icebridge (OIB).
IceBird impressions (Photo: Stefan Hendricks, Alfred-Wegener-Institut)
Much of AWI’s research is conducted in the inaccessible, ice-covered regions of the Arctic and Antarctic, making research aircraft indispensable. Currently AWI relies on the research planes Polar 5 and Polar 6. These two Basler BT-67 planes are old DC-3 aircraft specially modified for flying under extreme polar conditions and for scientific or logistical missions.
Instrumentation
The Instrumentation of AWI's Polar 5 and Polar 6 research aircraft includes an EM-Bird, a laser scanner, and a snow radar. (Graphic: Alfred-Wegener-Institut)
Sensor
Description
Application
EM-Bird
The purpose-built EM-Bird is a towed sensor that measures the combined thickness of the sea ice and its snow layer. The measurement principle is based on electromagnetic induction sounding at a frequency of 4 KHz. More information can be found here: Link
Summer & Winter
Laserscanner
Airborne laserscanner (Riegl VQ580) provide high-resolution information of the sea ice surface topography. This information is used to estimate the roughness of the sea ice surface as well as freeboard, a crucial parameter for remote sensing of sea ice thickness
Summer & Winter
Aerial Photography
A nadir pointing camera for providing photos of the sea ice surface along the survey line of the aircraft.
Summer & Winter
Snow Radar
An ultra-wide band FMCW (frequency modulated continuous wave) radar operating at 2-18 GHz that is used to measure snow depth on sea ice surfaces. The radar is designed by the Center for Remote Sensing of Ice Sheets (CRESIS).
Winter
Selected scientific papers
Haas, C., Hendricks, S., Eicken, H., Herber, A., Synoptic airborne thickness surveys reveal state of the Arctic sea ice cover, Geoph. Res. Lett., 37, L09501, doi:10.1029/2010GL042652, 2010.
Krumpen, T. , Gerdes, R. , Haas, C. , Hendricks, S. , Herber, A. , Selyuzhenok, L. , Smedsrud, L. H. and Spreen, G. (2016): Recent summer sea ice thickness surveys in Fram Strait and associated ice volume fluxes , The Cryosphere, 10 , pp. 523-534 . doi: 10.5194/tc-10-523-2016