Polar maps of C-band backscatter parameters from the Advanced Scatterometer

Abstract

Abstract. Maps of backscatter anisotropy parameters from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Advanced Scatterometer (ASCAT), a C-band fan-beam scatterometer, contain unique and valuable data characterising the surface and subsurface of various cryospheric elements, including sea ice and ice sheets. The computational expense and considerable complexity required to produce parameter maps from the raw backscatter data inhibits the wider adoption of ASCAT data. Here, backscatter anisotropy parameter maps gridded at a resolution of 12.5 km per pixel are made available to the community in order to facilitate the exploitation of these parameters for cryospheric applications. These maps have been calculated from the EUMETSAT Level 1B sigma0 product acquired from ASCAT on board MetOp-A, MetOp-B and MetOp-C. The dataset is unique in that it prioritises anisotropy characterisation over temporal resolution, and combines ASCAT data from multiple platforms. The parameterisation chosen assumes a linear falloff of backscatter with incidence angle and a 4th order Fourier series parameterisation of azimuth angle anisotropy. The product (Fraser and Cartwright, 2021) is available at https://doi.org/10.26179/5dd60df7469e2 presented on three time scales depending on orbital platform availability: 5-day (2007 to present – MetOp-A only – suitable for users requiring a long time-series), 2-day (2013 to present – MetOp-A and -B), and 1-day resolution (2019 – present – MetOp -A, -B and -C – suitable for users needing both high temporal resolution and detailed anisitropy characterisation).