Nora Greenwood, Melinda Webster, David Clemens‐Sewall, Bonnie Light, Donald K. Perovich, Savannah Byron, Torben Blei, Ruzica Dadić, Hannah Haines, Margret Menke, Marcel Nicolaus, Nahid Welteke, Florian Zimmer
Spectral albedo measurements of the sea ice surface were collected with an Analytical Spectral Devices (ASD) FieldSpec Pro 3 spectroradiometer with a custom spectralon cosine collector approximately 1 meter above the surface during the CONTRASTS expedition. During July – August 2025, repeat visits were made to sea ice floes representative of first-year, deformed first-year, and multi-year sea ice. Four types of albedo collections were made: (1) every 5 meters along “transects” 65-200 meters in length and often colocated with other field measurements, (2) at specific “library” sites of sea ice conditions of interest, (3) at “experiment” sites where the surface was manually manipulated, and (4) at “colocated” sites coordinated with other field measurement collections. Transects were established along representative surface conditions of the floe, including melt ponds, bare sea ice, snow-covered sea ice, and local topography (e.g., rafted ice), taking into account co-location with other measurements and logistical feasibility. Spectral data processing included a parabolic offset correction between 750 and 1000 nm and quality control flags. Observed sky conditions, surface types, the surface thickness manually measured with a folding ruler, and position notes are included in all data files.