Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model
Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400–900 nm) were found to be on average 0.15–0.20 under bare ice, and 0.39–0.46 under ponded ice. Radiative transfer modelling was d...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-09-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/11/2137/2017/tc-11-2137-2017.pdf |
| Summary: | Under-ice irradiance measurements were done on ponded first-year pack ice
along three transects during the ICE12 expedition north of Svalbard. Bulk
transmittances (400–900 nm) were found to be on average 0.15–0.20
under bare ice, and 0.39–0.46 under ponded ice. Radiative transfer modelling
was done with a plane-parallel model. While simulated transmittances deviate
significantly from measured transmittances close to the edge of ponds,
spatially averaged bulk transmittances agree well. That is, transect-average
bulk transmittances, calculated using typical simulated transmittances for
ponded and bare ice weighted by the fractional coverage of the two surface
types, are in good agreement with the measured values. Radiative heating rates
calculated from model output indicates that about 20 % of the incident
solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in
pond itself, 15 % in the underlying ice). This large difference is due to
the highly scattering surface scattering layer (SSL) increasing the albedo of
the bare ice. |
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| ISSN: | 1994-0416 1994-0424 |