Improved Arctic Ocean Bathymetry Derived From DTU17 Gravity Model

The existing bathymetry map of the Arctic is a compilation of ship soundings and digitized contours. Due to the presence of all-year sea ice, costly operations and political restrictions, dense and full coverage of the Arctic is not possible, leaving huge gaps between the existing surveys. In this paper, we make use of the existing Arctic bathymetry IBCAOv3 and invert Arctic bathymetry from the recent altimetric gravity model DTU17, whose accuracy is improved significantly with revised data processing strategy.

The long and short wavelength components are preserved from IBCAOv3. The band-pass-filtering function proposed by Smith and Sandwell (1994, https://doi.org/10.1029/94JB00988) is adapted for the Arctic by reducing the cutoff wavelength. The predicted bathymetry is within 100 m on 85.8% of the grid nodes, when compared to the IBCAOv3.

The consistency of the prediction is validated with two independent profiles from Healy cruises conducted in 2016 over the Chukchi Cap. A questionable valley in the IBCAOv3 is detected with gravity and at this spot, bathymetry predicted from gravity is consistent with independent multibeam soundings.

The gravity-inverted bathymetry could be combined with ship soundings for the next generation of Arctic bathymetry map.