White blanket, blue waters: Tracing El Niño footprints in Canada

Abstract

The El Niño Southern Oscillation (ENSO) significantly influences global climate patterns, with one of the strongest warm phases (El Niño) occurring in 2023, altering precipitation and temperature regimes. In this study, the spatiotemporal variability in snow cover across Canadian provinces from December 2023 to February 2024 relative to long-term averages is explored. The NOAA-OISST, NOAA-CSFV2, and MODIS MOD10A1 remote sensing datasets were selected to assess the impacts of El Niño on snow cover changes and the subsequent effects on water availability, agricultural productivity, the municipal water supply, natural ecosystems, and wildfire risk in Canada. An analysis of sea surface temperature anomalies in the equatorial Pacific revealed that El Niño intensity and progression are linked to regional snow cover deviations. Compared with the long-term average, Canada’s snow cover area experienced significant declines in December 2023, January 2024, and February 2024, with decreases of 135,938 km² (−7.43 %), 309,928 km² (−15.26 %), and 136,406 km² (−4.57 %), respectively. The findings indicate significant disparities among provinces, with Ontario, Quebec, and Manitoba experiencing marked decreases in snow cover, whereas in Saskatchewan and Alberta, initial increases were followed by subsequent variability. In British Columbia, a late-season increase in snow was observed, whereas minor changes were noted in the Maritime provinces and Northern territories. The findings of this study highlight the importance of snow cover as an important factor that has a considerable impact on the hydrological cycle and agricultural productivity, influences environmental health and economic resilience, and is crucial for both natural ecosystems and human livelihoods.