Mathematical Estimation of Sea Ice Thickness

Abstract:

The Alaska Sea Ice Program is tasked with monitoring and forecasting ice conditions across the Alaska Region from Cook Inlet through the Bering, Chukchi, and Beaufort Seas. Monitoring shorefast ice along Alaska’s coasts is an integral part of operations from a public safety perspective. A challenge to these operations has been trying to discern thickness of ice from looking at our primary mode of observation, high-resolution satellite imagery. While loose pack ice exhibits characteristics in its shape and size that can be used as a proxy measurement for thickness, shorefast ice does not exhibit those same characteristics. A look at historical research showed that various methods existed, based on freezing degree days with respect to the freezing point of saltwater. Mathematical estimations of ice thickness were investigated using five techniques from Stefan (1891), Lebedev (1938), Zubov (1945), Anderson (1961), and Hibler (2003). These equations were tested using 10 years worth of late-season ice thickness data at Utqiagvik, Alaska to determine their viability for use in Alaska Sea Ice Program operations.