Currents under land fast sea ice from tilt sensor moorings in Wolstenholme Fjord, Greenland, 2017

The principal investigators of this project propose to design and develop an integrated underwater acoustic sensor network for ice-covered seas. The sensor and communication network will support 1) long-term, intelligent distributed Arctic observing systems, 2) assimilation of remote-sensing and in-situ under-ice measurements, and 3) regional and global climate modeling with real-time measurements. Such a network holds the promise to revolutionize under-ice ocean sampling in polar regions. Ocean currents and temperatures in Wolstenholme Fjord adjacent to Thule Air Base (TAB) in Greenland were profiled about 0.05 meter below the sea ice at three mooring location in March and April of 2017. The fjord was covered by land-fast sea ice and thus provided a stable platform from which to test, deploy, and recover a range of oceanographic and acoustic sensor systems via snowmobiles during day-light hours when air temperatures are generally above -25 degrees Celsius. Ocean currents were estimated from the drag on a pendulum attached to the sea ice that measured accelerations and magnetic field strength vectors in the all three spatial dimensions.