Climate impacts on the ice regime of an Atlantic river

Although the sensitivity of river ice processes to climatic inputs is well known, there is very little information on how a changing climate can affect the severity and frequency of ice jam events and their numerous ecological and socio-economic impacts. The present study adds to this information by examining the ice regime of the Southwest Miramichi River, New Brunswick, and identifying recent trends that may be linked to concomitant climatic variations. The timing of freeze-up and breakup, as well as the thickness of the winter ice cover, do not exhibit significant temporal trends. However, spring ice jamming is becoming more severe, and there is increasing potential for devastating mid-winter breakup events. These findings are consistent with increasing rainfall and snowfall amounts, as well as increasing river flows, during the winter and early spring. Unlike in most parts of Canada, slight cooling during the winter months was detected, consistent with cooling trends found elsewhere in Atlantic Canada. Implications for adaptation and infrastructure design are discussed.