Preprints
https://doi.org/10.5194/tc-2022-76
https://doi.org/10.5194/tc-2022-76
 
07 Apr 2022
07 Apr 2022
Status: this preprint is currently under review for the journal TC.

Metamorphism of Arctic marine snow during the melt season. Impact on spectral albedo and radiative fluxes through snow

Gauthier Vérin1,2, Florent Domine1,3, Marcel Babin1, Ghislain Picard2, and Laurent Arnaud2 Gauthier Vérin et al.
  • 1Takuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Université Laval, Québec, Canada
  • 2Univ. Grenoble Alpes, CNRS, Institut des Géosciences de l’Environnement (IGE), UMR 5001, Grenoble, 38041, France
  • 3Department of Chemistry and Centre for Northern Studies, Université Laval, Québec, Canada

Abstract. The energy budget of Arctic sea ice is strongly affected by the snow cover. Intensive sampling of snow properties was conducted near Qikiqtarjuak in Baffin Bay on typical landfast sea ice during two melt seasons in 2015 and 2016. The sampling included stratigraphy, vertical profiles of snow specific surface area (SSA), density and irradiance, and spectral albedo (300–1100 nm). Both years featured four main phases: I) dry snow cover, II) surface melting, III) ripe snowpack and IV) melt pond formation. Each phase was characterized by distinctive physical and optical properties. A high SSA value of 49.3 m2 kg-1 was measured during phase I on surface wind slabs together with a corresponding broadband albedo of 0.87. Phase II was marked by alternating episodes of surface melting which dramatically decreased the SSA below 3 m2 kg-1 and episodes of snowfall reestablishing pre-melt conditions. Albedo was highly time-variable with minimum values at 1000 nm around 0.45. In Phase III, continued melting led to a fully ripe snowpack composed of clustered rounded grains. Albedo began to decrease in the visible as snow thickness decreased but remained steady at longer wavelengths. Moreover, significant spatial variability appeared for the first time following snow depth heterogeneity. Spectral albedo was simulated by radiative transfer using measured SSA and density vertical profile, and impurity contents based on measurements. Simulations were most of the time within 1 % of measurements in the visible and within 2 % in the infrared. Simulations allowed the calculation of albedo and of the spectral flux at the top of the sea ice. These showed that photosynthetically active radiation fluxes at the bottom of the snowpack durably exceeded 5 W m-2 (about 9.2 µmol m-2 s-1) only when the snowpack thickness started to decrease at the end of Phase II.

Gauthier Vérin et al.

Status: open (until 02 Jun 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on tc-2022-76', Anonymous Referee #1, 24 May 2022 reply

Gauthier Vérin et al.

Data sets

The Green Edge initiative: understanding the processes controlling the under-ice Arctic phytoplankton spring bloom Phlippe Massicotte et al. https://doi.org/10.17882/59892

Model code and software

TARTES (Two-streAm Radiative TransfEr in Snow model) Ghislain Picard https://github.com/ghislainp/tartes

Gauthier Vérin et al.

Viewed

Total article views: 251 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
191 57 3 251 6 4
  • HTML: 191
  • PDF: 57
  • XML: 3
  • Total: 251
  • BibTeX: 6
  • EndNote: 4
Views and downloads (calculated since 07 Apr 2022)
Cumulative views and downloads (calculated since 07 Apr 2022)

Viewed (geographical distribution)

Total article views: 250 (including HTML, PDF, and XML) Thereof 250 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 24 May 2022
Download
Short summary
Snow physical properties on Arctic sea ice are monitored during the melt season. As snow grains grow and the snowpack thickness is reduced, the surface albedo decreases. The extra absorbed energy accelerates melting. Radiative transfer modeling shows that more radiation is then transmitted to the snow-sea ice interface. A sharp increase in transmitted radiation takes place when the snowpacks thins significantly and this coincides with the initiation of the phytoplankton bloom in the sea water.