Water temperature during the melting of lake ice

Water temperature and ice thickness were measured during the ice melt period at Bennett Bay, White Lake, Ontario. Water temperatures were as high as 7.5 degrees C under the melting ice cover. The heat needed to warm the water under the ice and to melt ice at the ice-water interface was calculated for different periods and compared with the heat available from solar radiation that penetrated the ice cover. It was concluded from these calculations that solar radiation penetrating the ice caused the relatively high water temperatures observed under the melting ice.La temp\ue9rature de l'eau et l'\ue9paisseur de la glace ont \ue9t\ue9 mesur\ue9es durant la p\ue9riode de la fonte \ue0 Bennett Bay, White Lake, Ontario. Les temp\ue9ratures de l'eau se sont \ue9lev\ue9es jusqu'\ue0 7.5 degr\ue9s C. sous la couche de glace fondante. La chaleur requise pour r\ue9chauffer l'eau sous la glace et la fondre entre les deux faces glace-eau a \ue9t\ue9 calcul\ue9e \ue0 diff\ue9 rentes p\ue9riodes et compar\ue9e avec la chaleur disponible \ue9 manant de radiation solaire qui p\ue9n\ue9trait la couche de glace. On a conclu de ces calculs que la radiation solaire p\ue9n\ue9trant la glace a caus\ue9 des temp\ue9ratures d'eau relativement \ue9lev\ue9es observ\ue9es sous la glace fondante.Peer reviewed: NoNRC publication: Ye