Winter Thermal Structure, Ice Conditions and Climate of Lake Champlain,

Winter thermal structure and ice conditions in the land-fast ice cover of Lake Champlain were studied in detail for the winters of 1975-76 and 1976-77. The lake was instrumented to a depth of 8.5 m with a string of highly calibrated thermistors attached to an ice mooring system and connected to a data logger at Shelburne Point, Vermont, during the winter of 1975-76 and at Gordon Landing on Grand Isle, Vermont, during 1976-77. This data logger automatically recorded water temperatures from the surface of the lake though snow, ice and water vertical profiles to the bottom of the lake every four hours. Pertinent meteorological parameters are presented for the appropriate measurement sites during the two winter periods, November 75-April 76, and November 76-April 77. Computations were made of freezing degree days C for both winters and correlated with ice formation dates. Predictions of ice growth, using the Stefan equation with an empirical coefficient, were correlated with actual ice growth. Documentation was made of the Lake Champlain Transportation Companys first attempt at wintertime navigation by ferry from Gordon Landing, Vermont, to Cumberland Head, New York, in a land fast ice cover during one of the coldest winters of this century. Author