Spatial and temporal variations of deep water in the Canada Basin

The formation, circulation, and physical properties of the deep water in the Arctic Ocean remain inadequately understood. This study examines the spatial and temporal variations in the characteristics of deep water in the Canada Basin of the Arctic Ocean. Distinct differences are observed in the spatial distributions of potential temperature between the minimum and bottom layers. From 2003 to 2023, the potential temperature of deep water has gradually increased, while salinity and potential density anomaly have decreased. The rise in the minimum potential temperature is attributed to warm inflows from the Barents Sea Branch of Atlantic Water. In contrast, the warming of the bottom layer is primarily driven by geothermal heat, with upward heat transfer inhibited by the double-diffusive staircase. The empirical formula used to estimate heat flux in the double-diffusive staircase may overestimate flux values, potentially due to the presence of smaller staircases.