Time of Onset of Full Thermal Stratification in Lake Ontario in Relation to Lake Temperatures in Winter

Abstract

Using records from 1965 to 1985 including temperature data from vessel surveys and remote sensing by aircraft and satellite, relationships are explored amongst winter severity, early spring water temperature, and the date on which thermal stratification is established throughout the lake. One extreme event stands out in 1983, in association with the anomolous extent of the El Niño current in the Pacific Ocean. Winter conditions in 1983 in Lake Ontario appear to be within the warmest 5% of winters on record: this is reflected in air and water temperatures and in the very early onset of full thermal stratification of Lake Ontario. The data provide a means of assessing the spring conditions of any particular year and also provide some predictive capability should one wish to schedule experiments to take advantage of particular thermal structures in spring or early summer.