An analysis of the basis of the Chaine model for ice accretion in freezing rain

The Chaine model is used in Canada to map ice thicknesses from freezing rain for the design of overhead power transmission lines. The model was also recently used for mapping ice thicknesses associated with climate change over the United States and Canada. I analyze the basis of that model, focusing on the characteristics of the wind tunnel runs the model relies on, which are intended to simulate sea spray icing. The conditions in the wind tunnel are not representative of weather conditions in freezing rain. However, the model's authors calculate the correction factor that controls the Chaine model results from dimensions of the sea spray ice accretions. The measurements that they use are inconsistent with freezing rain as well as with the conditions in the wind tunnel. I conclude that the Chaine model does not represent ice accretion in freezing rain.