Temperature and heating-induced temperature were measured along a chain of thermistors. Digital Thermistor Chain DTC15 is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the MOSAiC expedition on 07 November 2019. The thermistor chain was 4.16 m long and included sensors with a regular spacing of 2 cm. The resulting time series describes the evolution of temperature during the heating cycle of 20 s and after the heating cycle during the following 40 s as a function of geographic position (GPS), depth, and time between 05 November 2019 and 07 January 2020 in sample intervals of 6 hours. It also contains manually estimated positions of air-snow, snow-ice, and ice-water interfaces. The DTC was installed in the deformed second-year ice ridge next to RV Polarstern and remote sensing site RS1
