UCL Earth Sciences


Isobel Lawrence

“Towards improving thickness retrievals from Cryosat.”

PhD project title:

Towards improving thickness retrievals from Cryosat.

Isobel Lawrence
Project description:

The CryoSat-2 mission is equipped with a Ku-band synthetic aperture radar altimeter to measure ice surface and open water elevations, from which the sea ice freeboard and thus thickness can be computed. In several studies, the main scattering horizon is assumed to be given by the snow-ice interface, however recent work suggests that one cannot rule out an influence of radar backscatter from the snowpack. Furthermore, inaccurate estimates for snow depth and density can lead to large biases in ice thickness calculation from hydrostatic equilibrium considerations. A critical question therefore is whether we possess a sufficient understanding of the spatial and temporal distribution and evolution of snow and if we are using that knowledge to the full effect in modelling and retrieval methods. 

This project aims to better quantify the snow bias in CryoSat freeboard retrievals through (1) Studies of radar backscatter as a function of snow conditions (2) Comparison of CryoSat freeboard retrievals with other freeboard observations and ice mass-balance buoys and (3) Development of a new snow depth product based on meteorological and ice drift data.