CR 32:25-33 (2006)  -  doi:10.3354/cr032025

ABSTRACT: Large-scale atmospheric circulations and anomalies have significant influence upon seasonal weather over many parts of the world. We examined the impact of sunspot activity and large-scale atmospheric features on regional seasonal weather, as well as implications for crop yield and agronomy. The atmospheric variables analyzed included the stratospheric quasi-biennial wind oscillation (QBO), El Niño/Southern Oscillation (ENSO), and North American snow cover (NAS) on Canadian summer rainfall, regarded as a key variable for establishing grain yield. Because the study is an exploratory one, we focused on correlation coefficients between selected variables. The analysis is based on 55 yr of atmospheric, crop yield and climatic data for >50 weather stations over the Canadian Prairie region. Our study reveals that high (low) sunspot activity, an easterly (westerly) phase of the QBO, persistent La Niña (El Niño) conditions and heavier (lighter) than normal NAS in seasons leading up to the summer months are associated with low (high) summer rainfall.

KEY WORDS: Summer rainfall · Snow cover · Sunspots · ENSO · QBO · Canadian Prairie · North America