Thin ice growth

The thickening of ice covers has traditionally been calculated using a method in which the thickness is assumed proportional to the square root of the accumulated freezing degree days. Particularly for newly formed thin ice this method overpredicts the ice thickness. Consideration of the thermal resistance between the top of the ice and the atmosphere results in a method which predicts linear growth with time for thin ice and transitions to the t ½ growth at large thicknesses. The method proposed here is not new but seems to be rarely used even though it requires selection of only one coefficient. Data from several sources including initial river ice growth, sea ice growth, and sludge freezing are used to validate the method and bracket the coefficient.