https://doi.pangaea.de/10.1594/PANGAEA.993938Rückert, Janna ElisabethJanna ElisabethRückert0000-0001-9885-6576Institute of Environmental Physics, University of BremenBühler, LinnuLinnuBühlerUniversity of CologneMewes, Lars-HendrikLars-HendrikMewesWSL Institute for Snow and Avalanche Research SLFRisse, NilsNilsRisse0000-0002-7267-9353University of ColognePANGAEA2026Arcticnear-infraredsnowEvent labelCSV text fileCSV text file (File Size)ImageImage (File Size)Ice stationPS144PolarsternArctic Amplification (AC3)2024-08-16T11:21:02/2024-09-26T20:53:07Dataset10.1594/PANGAEA.99049610.57738/BZPM_0794_202520 data pointstext/tab-separated-valuesCreative Commons Attribution 4.0 InternationalDuring the Polarstern cruise PS144 from August 2024 to October 2024 in the central Arctic Ocean snow and ice surface near-infrared images were collected on 10 ice stations. The device, called SnowImager (snowimager.ch), consists of a near infrared illumination system and two cameras to capture the reflected light while the housing acts as a light shield. The width and height of the inside of the box is 30 cm x 40 cm. The NIR camera records images at two dedicated wavelenghts, 850 nm and 940 nm. The specific surface area and density of the snow can be derived from these reflectance images.
Calibration images were taken at the start of each station. We performed two types of measurements: Either we took images of the snow/surface scattering layer surface along transects, or, if the snow was sufficiently deep, we used the SnowImager in the excavated snowpit walls to record the vertical (in addition to the horizontal) spatial variability. Here, the NIR images also allow identification of snow layers with different snow grains (i.e., specific surface areas). All measurements were done within the vicinity of the footprint of the onboard microwave radiometers installed for the VAMPIRE project (that is, in about 25 m distance to the port bow of Polarstern mostly measured along T-shaped transects with side lengths of 5 to 7 meters). The datasets consists of the raw measurements (the photos as .dng files) and databases per ice station containing the metadata for the photos. For example, the location along a transect for each image is described in these databases. The databases are designed to be used with the appropriate SnowImager software (https://code.wsl.ch/snow-physics/snowimagerpro) in order to analyze the photos (e.g., to calculate reflectances or the specific surface area). For more information about these measurements the user is referred to Chapter 6.4 of the cruise report.42.692716-150.66699384.51169789.944844Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhavenhttps://doi.org/10.13039/501100003207AWI_PS144_06SeaIcePhys. (ArcWatch1/TransArc3)German Research Foundationhttps://doi.org/10.13039/501100001659268020496TRR 172: ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms