Sensing wave patterns in sea ice with Sentinel-2

In English Sentinel-2 snow-ice

Simon Gascoin, 15 juillet 2022

Collard et al. (2022) have shown that Sentinel-2 can be used to estimate the wave spectrum in the presence sea ice. The waves tilt the sea ice surface and therefore modulate the reflected radiation that is received by Sentinel-2 sensor. The wave spectrum extracted from the image can even be used to invert the wave height.

I selected a region in the Arctic ocean (78.85°N,49.68°E) captured on 23 March 2019 and stretched the contrast of band 04 surface reflectance. The wavy signal is clearly visible.

But there is more: the authors also mention that 1 second delay between the acquisition of the band 02 and band 04 can be used to remove « the 180° ambiguity on wave propagation ».

Indeed if we compare B04 and B02 we can see that the undulation patterns changes between both acquisitions.

Band 02 and band 04 (78.79°N, 50.12°E 23 March 2019 as in Fig. 7 of Collard et al. 2022)

 

Collard, F., Marié, L., Nouguier, F., Kleinherenbrink, M., Ehlers, F., & Ardhuin, F. (2022). Wind-wave attenuation in Arctic sea ice: A discussion of remote sensing capabilities. Journal of Geophysical Research: Oceans, 127, e2022JC018654, https://doi.org/10.1029/2022JC018654

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