Retrieval of snow layer and melt pond properties on Arctic sea ice from airborne imaging spectrometer observations
<p>A melting snow layer on Arctic sea ice, as a composition of ice, liquid water, and air, supplies meltwater that may trigger the formation of melt ponds. As a result, surface reflection properties are altered during the melting season and thereby may change the surface energy budget. To stud...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-08-01
|
| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/16/3915/2023/amt-16-3915-2023.pdf |
| Summary: | <p>A melting snow layer on Arctic sea ice, as a composition of ice, liquid water, and air, supplies meltwater that may trigger the formation of melt ponds. As a result, surface reflection properties are altered during the melting season and thereby may change the surface energy budget. To study these processes, sea ice surface
reflection properties were derived from airborne measurements using imaging spectrometers. The data were collected over the closed and marginal Arctic sea ice zone north of Svalbard in May–June 2017. A retrieval approach based
on different absorption indices of pure ice and liquid water in the near-infrared spectral range was applied to the campaign data. The technique enabled us to retrieve the spatial distribution of the liquid water
fraction of a snow layer and the effective radius of snow grains. For observations from three research flights, liquid water fractions between 6.5 % and 17.3 % and snow grain sizes between 129 and <span class="inline-formula">414</span> <span class="inline-formula">µm</span> were derived. In addition, the melt pond depth was
retrieved based on an existing approach that isolates the dependence of a melt pond reflection spectrum on the pond depth by eliminating the reflection contribution of the pond ice bottom. The application of the approach to several case studies revealed a high variability of melt pond depth, with maximum depths of 0.33 m.
The results were discussed considering uncertainties arising from the airborne reflection measurements, the setup of radiative transfer simulations, and the retrieval method itself.
Overall, the presented retrieval methods show the potential and the limitations of airborne measurements with imaging spectrometers to map the transition phase of the Arctic sea ice surface, examining the snow layer
composition and melt pond depth.</p> |
|---|---|
| ISSN: | 1867-1381 1867-8548 |