Connectivity between Eurasian snow cover extent and Canadian snow water equivalent and river discharge

Abstract

We explore pan‐Arctic climate connectivity by examining historical time series of satellite‐based measurements of Eurasian snow cover extent and of observed Canadian snow water equivalent (SWE) and freshwater discharge, with a focus on the Churchill River Basin of Labrador and the Chesterfield Inlet Basin of Nunavut. Analysis of the data reveals statistically significant positive (negative) correlations between spring and summer Eurasian standardized snow cover extent anomalies and annual maximum monthly SWE as well as freshwater discharge in the Churchill River (Chesterfield Inlet) Basin the following year. A spatially coherent response to the forcing is observed since 19 rivers draining more than 0.6 × 106 km2 of northern Quebec and Labrador and with a mean annual total discharge of 320 km3 yr−1 show statistically significant positive correlations to the annual Eurasian standardized snow cover extent anomalies. The origin of this pan‐Arctic climate connectivity is related to the persistent nature of the Eurasian snow cover extent anomalies and the associated accumulated gains or deficits in the surface radiation and water budgets that impose a memory in the climate system. The Eurasian snow cover extent anomalies provide some degree of predictability (up to 1 year in advance) of the surface water budget in the Churchill River and Chesterfield Inlet Basins. They further suggest that a declining trend in Eurasian snow cover extent will yield decreasing (increasing) SWE and river discharge in the Churchill River (Chesterfield Inlet) Basin in the 21st century.