Ice mass balance (IMB) buoy data PS81/517 from Weddell Sea, Antarctica, 2013. The buoy was deployed together with an automatic weather station buoy (see under related) on sea ice station PS81/517 from Research Vessel Polarstern in the Antarctic Weddell Sea in austral winter 2013 (cruise leg ANT-XXIX/6, AWECS campaign). The IMB buoy provides data between 2013-07-31T17:28:00 and 2013-10-11T00:30:00.The IMB buoy was kindly provided by the Scottish Association for Marine Science (SAMS). The IMB buoy consisted of a thermistor string of 5 m length, with a 2 cm sensor spacing. Interfaces were determined by hand. Heating cycle data was of poor quality, so the interfaces were picked mostly based on temperature. The ice interface will be pretty good (~2 cm accuracy), and the snow is probably a bit more inaccurate. The bottom interface was determined from the existence of a knee in the temperature profile where apparent. The top interface was picked based on the transition to constant temperature in the air and the diurnal variability. This may be subject to some bias, but note that the changes are only a few cm until the end where the IMB probably died because it got washed over (based on recorded temperatures). No flooding is apparent in the measurements.