FY 1987

An algorithm for prediction of vessel icing

Overland, J.E., C.H. Pease, R.W. Preisendorfer, and A.L. Comiskey

In Proceedings of International Workshop on Winds and Icing, Halifax, Nova Scotia, 7–11 October 1985, 248–256 (1986)

An important meteorological variable for operations in high latitudes is the rate of accumulation of ice on vessels and structures. A set of 85 icing observations were collected for Alaskan waters from intermediate size vessels (20-75 m) during 1979 to 1984, which were verified by interviews of the vessel operators and by comparison with National Weather Service analyses. Of the set of 85, 58 were open-ocean observations where the vessel was not heading down-wind; 25% of the reduced set had icing rates in excess of 2.0 cm/hr. An algorithm has been developed for relating vessel potential icing rate to a simplified predictor which considers wind speed, fetch, and air and sea temperatures. The new algorithm predicts icing rates greater than three times those of most previous icing nomograms.