Ice regimes, ice jams, and a changing hydroclimate, Saint John (Wolastoq) River, New Brunswick, Canada

Ice formation, growth, and breakup along the Saint John River (SJR) affects its hydraulic and ecological regimes and leads to the potential for ice jamming that has caused severe flooding and ice runs resulting in loss of life, property damage, and loss of, or damage to, infrastructure. A synopsis of ice regimes and ice jamming along the SJR from Dickey, Maine, USA to Woodstock, New Brunswick, Canada is summarized in this paper. Trends in relevant hydroclimatic variables such as monthly mean air temperature (December to April), total winter snow (December to March), length of the ice season, rainfall, and monthly mean and peak winter and spring flows are discussed. Projections of future ice regimes under a changing climate are provided, with anticipated changes in the ice regime of the SJR explained in the wider context of changes to the cryosphere.