Wind Climatology for the Great Lakes Region as Derived from the North American Regional Reanalysis

The climate and climate variability of low-level winds over the Great Lakes region of the United States is examined using 30-year (1979-2008) wind records from the North American Regional Reanalysis (NARR), a three-dimensional, high spatial and temporal resolution, and dynamically consistent climate dataset. The analyses focus on spatial distribution and seasonal and interannual variability of wind speed at 80 m above the ground, the hub height of the modern, 77-m diameter, 1500 kW wind turbines. The daily mean wind speeds exhibit a large seasonal variability, with the highest mean wind speed in November through January and the lowest in July and August. The spatial variability of the annual mean winds is small across the entire region, and is dominated by land-water contrasts with stronger winds over the lake surface than over land. Larger interannual variability is found during the winter months, while smaller variations occur in mid to late summer. The interannual variability appears to have some connections to ENSO, with lower mean wind speeds and more frequent occurrences of lulls during major El Niño episodes. According to NARR data and the criteria established by wind energy industry, the areas over Lake Superior, Michigan, and Ontario appear to be rich in wind resources, but most land areas in the region are either unsuitable or marginal for potential wind energy development.