Real time monitoring of snow depth and ice thickness by SIMBA ice mass balance buoys deployed in the Arctic Ocean during 2018 field expeditions

An ice mass balance buoy (IMB) monitors the evolution of snow and ice cover on the sea, ice sheets, glaciers, mountains and lakes through the measurement of various variables. In the first IMBs, the crucial measurement of snow and ice thickness has been achieved using acoustic sounders, but a more recently developed low cost IMB called the Snow and Ice Mass Balance Array (SIMBA) measures vertical temperature profiles through the air-snow-ice-water column using a high-resolution thermistor string with passive and active measurement capabilities. The determination of snow depth and ice thickness from SIMBA temperature profiles has so far been a manual process, but an automated algorithm has been developed recently. The algorithm is based on heat flux continuity, a threshold ratio between thermal heat conductivity of snow and ice, and minimum resolution (±0.0625°C) of the temperature sensors. We present testing of the algorithm, and comparison of the results with manual analyses and in situ borehole measurements. The algorithm has two modules. One is designed to process historical archived SIMBA data (HD), and the other one is targeted to process online near-real-time SIMBA data (RT). In this study, we present SIMBA results using RT module. SIMBA data are obtained from several Arctic field expeditions in 2018. The performance of SIMBA RT algorithm is then assessed and results are compared with manual analyses.