“…Since the early 2000s, autonomous and Lagrangian platforms and sensors (ALPS) have contributed significantly to the way the ocean is observed in the lower latitudes and coastal regions (Riser et al, 2016;Rudnick, 2016). At high latitudes, the Arctic Ocean has become increasingly more observable, with new data sets from satellite altimetry (e.g., Laxon et al, 2013), gravimetry (Watkins et al, 2015), in situ Ice-Tethered Profilers (ITP, measuring subsurface hydrography; Krishfield et al, 2008;Timmermans et al, 2008;Toole et al, 2011), and a variety of sensors on autonomous platforms (Lee et al, 2010, andThomson, 2017, in this issue).…”