Sea ice draft measured by upward looking sonar at mooring site AWI227-4

Lograte: 3 min. The data identification flags (columns 6 & 8) stand for: 1=ice, 2=thin ice/open water, 0=water, empty cells=rejected/erroneous data. Depth was calculated by: (p_uls-p_atm)/(rho * g), where p_uls is the measured water pressure, p_atm is the atmospheric pressure from ECMWF (http://www.ecmwf.int) reanalysis, rho is 1027 kg/m**3, and g is the latitude-dependent acceleration of gravity.