Author(s): Daniel J. Titze; Jay A. Austin
Keywords: No Keywords
Abstract: US/Canada Laurentian Great Lakes, and almost all of what we know concerning ice on these large lakes is derived either from remote sensing or from numerical modeling studies. During the very cold winter of 2013-2014, under-ice moorings in Lake Superior provided a unique view of a range of ice characteristics, all of which suggest that ice on these lakes behaves more like oceanic ice than ice on smaller lakes. Specific results novel to fresh water include: acoustic velocity measurements of ice drift at an offshore site shows that ice typically drifts at roughly 3% of the regional wind speed, and at an angle of roughly 20°to the right of the wind, consistent with Ekman theory, but also show that the ice is capable of becoming fast. Ice keels are observed up to 12m thick, and are frequently more than 6m thick, which suggests that a significant fraction of the total ice volume on the lake can be bound up in keels and ridges.