Preprints
https://doi.org/10.5194/tc-2021-149
https://doi.org/10.5194/tc-2021-149

  08 Jun 2021

08 Jun 2021

Review status: this preprint is currently under review for the journal TC.

Retrieval and parametrisation of sea-ice bulk density from airborne multi-sensor measurements

Arttu Jutila1, Stefan Hendricks1, Robert Ricker1,a, Luisa von Albedyll1, Thomas Krumpen1, and Christian Haas1,2 Arttu Jutila et al.
  • 1Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
  • 2Institute of Environmental Physics, University of Bremen, Bremen, Germany
  • apresent address: Technology Department, Norwegian Research Centre, Tromsø, Norway

Abstract. Knowledge of sea-ice thickness and volume depends on freeboard observations from satellite altimeters and in turn on information of snow mass and sea-ice density required for the freeboard-to-thickness conversion. These parameters, especially sea-ice density, are usually based on climatologies constructed from in situ observations made in the 1980s and before while contemporary and representative measurements are lacking. Our aim with this paper is to derive updated sea-ice bulk density estimates suitable for the present Arctic sea-ice cover and a range of ice types to reduce uncertainties in sea-ice thickness remote sensing. Our sea-ice density measurements are based on over 3000 km of high-resolution collocated airborne sea-ice and snow thickness and freeboard measurements in 2017 and 2019. Sea-ice bulk density is derived assuming isostatic equilibrium for different ice types. Our results show higher average bulk densities for both first-year ice (FYI) and especially multi-year ice (MYI) compared to previous studies. In addition, we find a small difference between deformed and possibly unconsolidated FYI and younger MYI. We find a negative-exponential relationship between sea-ice bulk density and sea-ice freeboard and apply this parametrisation to one winter of monthly gridded CryoSat-2 sea-ice freeboard data. We discuss the suitability and the impact of the derived FYI and MYI bulk densities for sea-ice thickness retrievals and the uncertainty related to the indirect method of measuring sea-ice bulk density. The results suggest that retrieval algorithms be adapted to changes in sea-ice density and highlight the need of future studies to evaluate the impact of density parametrisation on the full sea-ice thickness data record.

Arttu Jutila et al.

Status: open (until 03 Aug 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Arttu Jutila et al.

Arttu Jutila et al.

Viewed

Total article views: 245 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
185 57 3 245 1 2
  • HTML: 185
  • PDF: 57
  • XML: 3
  • Total: 245
  • BibTeX: 1
  • EndNote: 2
Views and downloads (calculated since 08 Jun 2021)
Cumulative views and downloads (calculated since 08 Jun 2021)

Viewed (geographical distribution)

Total article views: 243 (including HTML, PDF, and XML) Thereof 243 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 15 Jun 2021
Download
Short summary
Sea-ice thickness retrieval from satellite altimeters relies on assumed sea-ice density values, because density cannot be measured from space. We derived bulk densities for different ice types using airborne laser, radar, and electromagnetic induction sounding measurements. Compared to previous studies, we found high bulk density values due to ice deformation and younger ice cover. Using sea-ice freeboard, we derived a sea-ice bulk density parametrisation that can be applied to satellite data.