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

Correlates of Canadian Prairie summer rainfall: implications for crop yields

Ray Garnett1,*, Niru Nirupama2, C. Emdad Haque3, T. S. Murty4

1Agro Climatic Consulting, 1340 Aikins Street, Winnipeg, Manitoba R2V 2C7, Canada
2School of Administrative Studies, Rm. 210A, Atkinson College, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
3Natural Resource Institute, University of Manitoba, 70 Dysart Road, Winnipeg, Manitoba R3T 2N2, Canada
4Department of Civil Engineering, University of Ottawa, 161 Louis Pasteur Room A106, Ottawa, Ontario K1N 6N5, Canada

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


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