CRREL-type IMB ZS2009 is an autonomous instrument that was installed on the landfast sea ice in Prydz Bay, east Antarctica in July 2009. The buoy was deployed at 69.36°S; 76.42°E, ~3 km from the coast of Station Zhongshan with initial thicknesses of snow and ice of 0.01 and 1.00 m, respectively, on 10 July 2009. Snow/Ice temperature and mass balance were measured along a chain of thermistors and via acoustic rangefinder sounders. The thermistor chain was 4.5 m long and included 45 sensors with a regular spacing of 10cm. The acoustic sensors were located above and below the ice surface, monitoring the position of the top and bottom surfaces of the ice. The resulting time series describes the evolution of temperature and snow/ice mass balance as a function of time between 10 July and 12 December 2009 in sample intervals of 2 hours. The data from the underwater acoustic sounder were available only from 10 July to 2 August 2009 because of a sensor failure.

The data set has been processed as follows: obvious inconsistencies (missing values) and and unrealistic values have been removed.