The Cryosphere (Sep 2024)

On the importance to consider the cloud dependence in parameterizing the albedo of snow on sea ice

  • L. Foth,
  • W. Dorn,
  • A. Rinke,
  • E. Jäkel,
  • H. Niehaus

DOI
https://doi.org/10.5194/tc-18-4053-2024
Journal volume & issue
Vol. 18
pp. 4053 – 4064

Abstract

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The impact of a slightly modified broadband snow surface albedo parameterization, which explicitly considers the cloud dependence of the snow albedo, is evaluated in simulations of a coupled regional climate model of the Arctic. The cloud dependence of the snow albedo leads to a more realistic simulation of the variability of the surface albedo during the snowmelt period in late May and June. In particular, the reproduction of lower albedo values under cloud-free/broken-cloud conditions during the snowmelt period represents an improvement and results in an earlier disappearance of the snow cover and an earlier onset of sea-ice melt. In this way, the consideration of the cloud dependence of the snow albedo results in an amplification of the two-stage snow/ice albedo feedback in the model. This finds expression in considerably increased sea-ice melt during the summer months and ends up in a new quasi-stationary equilibrium in sea ice with statistically significant lower sea-ice volume and statistically significant lower summer sea-ice area.