Role of sea surface temperature variability on the risk of Canadian wheat, barley, and oat yields

Abstract

Surface air temperature (SAT) and precipitation in Prairie (Western) and Maritime (Eastern) Canada are influenced by the El Niño Southern Oscillation (ENSO) and Atlantic Multidecadal Oscillation (AMO), respectively. However effects of ENSO and AMO on major crop yield in Canada is yet to be understood. Here we investigate the longest record (1908–2017) of wheat, barley, and oat yield as well as its associated risk with summer (May-September) ENSO and AMO interannual and multidecadal variability in Prairie and Maritime, respectively. We used generalized linear models with autocorrelative residuals to assess region- and crop-specific associations between ENSO, AMO, surface air temperatures, and precipitation on crop yield. After adjusting for covariates our models show that a positive phase of the AMO (in comparison to negative phase) significantly reduces the risk of Maritime crop yields by ~3–12%, with both extreme heat and wet precipitation found to be significant risk factors for reducing yields. Summer El Niño or La Niña was found to have a small, insignificant effect on yield in the Prairie region, with no effects found on crops in Maritimes. Therefore, analysis of Atlantic oceanic variability can offer insight into major crop yield variability in Maritime Canada.