Arctic sea ice albedo: Spectral composition, spatial heterogeneity, and temporal evolution observed during the MOSAiC drift

Journal Article · Thu Aug 04 00:00:00 EDT 2022 · Elementa

DOI:https://doi.org/10.1525/elementa.2021.000103· OSTI ID:1882215

Light, Bonnie ^[1]; Smith, Madison M. ^[1]; Perovich, Donald K. ^[2]; Webster, Melinda A. ^[3]; Holland, Marika M. ^[4]; Linhardt, Felix ^[5]; Raphael, Ian A. ^[2]; Clemens-Sewall, David ^[2]; Macfarlane, Amy R. ^[6]; Anhaus, Philipp ^[7]; Bailey, David A. ^[4]

---

1. Univ. of Washington, Seattle, WA (United States)
2. Dartmouth College, Hanover, NH (United States)
3. Univ. of Alaska Fairbanks, AK (United States)
4. National Center for Atmospheric Research, Boulder, CO (United States)
5. Christian-Albrechts-Univ. zu Kiel (Germany)
6. WSL Inst. for Snow and Avalanche Research SLF, Davos (Switzerland)
7. Alfred-Wegener-Inst., Bremerhaven (Germany)

The magnitude, spectral composition, and variability of the Arctic sea ice surface albedo are key to understanding and numerically simulating Earth’s shortwave energy budget. Spectral and broadband albedos of Arctic sea ice were spatially and temporally sampled by on-ice observers along individual survey lines throughout the sunlit season (April–September, 2020) during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. The seasonal evolution of albedo for the MOSAiC year was constructed from spatially averaged broadband albedo values for each line. Specific locations were identified as representative of individual ice surface types, including accumulated dry snow, melting snow, bare and melting ice, melting and refreezing ponded ice, and sediment-laden ice. The area-averaged seasonal progression of total albedo recorded during MOSAiC showed remarkable similarity to that recorded 22 years prior on multiyear sea ice during the Surface Heat Budget of the Arctic Ocean (SHEBA) expedition. In accord with these and other previous field efforts, the spectral albedo of relatively thick, snow-free, melting sea ice shows invariance across location, decade, and ice type. In particular, the albedo of snow-free, melting seasonal ice was indistinguishable from that of snow-free, melting second-year ice, suggesting that the highly scattering surface layer that forms on sea ice during the summer is robust and stabilizing. In contrast, the albedo of ponded ice was observed to be highly variable at visible wavelengths. Notable temporal changes in albedo were documented during melt and freeze onset, formation and deepening of melt ponds, and during melt evolution of sediment-laden ice. While model simulations show considerable agreement with the observed seasonal albedo progression, disparities suggest the need to improve how the albedo of both ponded ice and thin, melting ice are simulated.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Atmospheric Radiation Measurement (ARM) Data Center
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Contributing Organization: Pacific Northwest National Laboratory (PNNL); Brookhaven National Laboratory (BNL); Argonne National Laboratory (ANL); Oak Ridge National Laboratory (ORNL)
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 1882215
• Journal Information: Elementa, Vol. 10, Issue 1; ISSN 2325-1026
• Publisher: University of California Press
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
Sea ice
Albedo
Melt ponds
Ice-optics
Sediment
Surface scattering layer