A distributed network of temperature chains to autonomously monitor sea ice evolution on an ice floe during MOSAiC

Thermistor chains with the ability to record air, snow, ice and ocean temperatures are widely used on autonomous ice mass balance buoys (IMBs), which record the evolution of sea ice thickness and snow depth at a fixed site. The additional ability to actively heat their surrounding enables them to also determine sea ice thermal properties, as well as yielding more detailed information about surface and internal melt processes. In modern IMBs, these themistors chains are usually closely tied to a specific electronic setup, making it impossible to operate them independently. However, recent developments enable them to now be operated on any platform equipped with an RS232 interface. In combination with other improvements, such as increased resolution, sturdiness, and reliability, it is now the right time to look for applications beyond their use in (expensive) IMBs. Here we introduce the idea and concept to deploy a distributed network of such thermistor chains on the ice floe where RV Polarstern is anchored during the MOSAiC experiment. Powered by regular lead batteries and controlled by a cheap, commercially available microcontroller, the units will send their temperature and heating profiles in fixed intervals (e.g. 1 h) or on request to a central receiving unit on the ship via a direct communication link. Based on the incoming data in combination with high-resolution electromagnetic thickness surveys, a 3D temperature and thermal property map of the ice floe and the surrounding atmosphere and ocean is generated, which is then used to calculate sea ice thickness and snow depth in the covered area. Complementing regular sea ice thickness and snow depth surveys by other methods, this information is expected to be very valuable for many studies during MOSAiC