Recent years have seen extreme changes in the Arctic. Particularly striking are changes within the Pacific sector of the Arctic Ocean, and especially in the seas north of the Alaskan coast. These areas have experienced record warming, reduced sea ice extent, and loss of ice
in areas that had been ice‐covered throughout human memory. Even the oldest and thickest ice types have failed to survive through the summer melt period in areas such as the Beaufort Sea and Canada Basin, and fundamental changes in ocean conditions such as earlier phytoplankton blooms may be underway. A basic question that is significant for the entire Earth system is whether these regions have passed a tipping point, such that they are now essentially acting as sub‐Arctic seas where ice disappears in summer, or instead whether the changes are transient, with the potential for the ice pack to recover. The answer may depend largely on conditions in areas known as marginal ice zones (MIZ); areas where the "ice‐albedo feedback" driven by solar warming is highest, ice melt is extensive, and where human and marine mammal activity is greatest.
Despite the significance of the MIZ, basic parameters such as sea surface temperature (SST), sea surface salinity (SSS), and a range of sea ice characteristics are still insufficiently understood in these areas, and especially so during the summer melt period. The project proposed here, identified collectively as the "Marginal Ice Zone Ocean and Ice Observations and Processes EXperiment" (MIZOPEX), will directly address these information gaps through a targeted, intensive observing campaign that exploits unique capabilities of multiple classes of UAS (NASA SIERRA, Insitu ScanEagles, and a microUAS) combined with in‐situ sensing and satellite observations. Specific research areas to be addressed using MIZOPEX data are: relationships between ocean skin temperatures and subsurface temperatures and how these evolve over time in an Arctic environment during summer; variability in sea ice conditions such as thickness, age, and albedo within the MIZ; interactions of SST, salinity and ice conditions during the melt cycle; and validation of satellite‐derived SST and ice concentration fields provided by AVHRR, MODIS, AMSR‐E and the NPP/JPSS VIIRS.
