Temporal and Spatial Variability of Great Lakes Ice Cover, 1973–2010*

Abstract

In this study, temporal and spatial variability of ice cover in the Great Lakes are investigated using historical satellite measurements from 1973 to 2010. The seasonal cycle of ice cover was constructed for all the lakes, including Lake St. Clair. A unique feature found in the seasonal cycle is that the standard deviations (i.e., variability) of ice cover are larger than the climatological means for each lake. This indicates that Great Lakes ice cover experiences large variability in response to predominant natural climate forcing and has poor predictability. Spectral analysis shows that lake ice has both quasi-decadal and interannual periodicities of ~8 and ~4 yr. There was a significant downward trend in ice coverage from 1973 to the present for all of the lakes, with Lake Ontario having the largest, and Lakes Erie and St. Clair having the smallest. The translated total loss in lake ice over the entire 38-yr record varies from 37% in Lake St. Clair (least) to 88% in Lake Ontario (most). The total loss for overall Great Lakes ice coverage is 71%, while Lake Superior places second with a 79% loss. An empirical orthogonal function analysis indicates that a major response of ice cover to atmospheric forcing is in phase in all six lakes, accounting for 80.8% of the total variance. The second mode shows an out-of-phase spatial variability between the upper and lower lakes, accounting for 10.7% of the total variance. The regression of the first EOF-mode time series to sea level pressure, surface air temperature, and surface wind shows that lake ice mainly responds to the combined Arctic Oscillation and El Niño–Southern Oscillation patterns.

The role of meteorological processes in the description of uncertainty for climate change decision-making

“…The amount of lakeeffect precipitation is strongly influenced by the amount of ice cover on the lake (Brown and Duguay 2010; Wright et al 2012), and lake-ice is not simulated by the GCMs. In the past, the lake has been frozen, but reductions in ice cover of more than 70 % have already been documented (Wang et al 2012). Therefore, the source of water for the underlying weather systems is changed and this has been accompanied by large increases in lake-effect snow on the upper peninsula of Michigan (Andresen et al 2012;Burnett et al 2003;Ellis and Johnson 2004;Kunkel et al 2009).…”

Engaging Marina and Harbor Operators in Climate Adaptation

“…Marinas and harbors experience a variety of climate change impacts including shorter winters (Kling and Wuebbles 2005), warmer temperatures (U.S. Global Change Research Program 2009), more intense storms (Mortsch, Alden, and Scheraga 2003), reduction in ice cover (Wang et al 2012), and fluctuating lake levels (Holman et al 2012). Concurrently, marina infrastructure is aging and deteriorating, even as securing funding for needed improvements becomes increasingly difficult (USACE 2012).…”

Cold Water and High Ice Cover on Great Lakes in Spring 2014

“…Data collected and compiled by the Canadian Ice Service, the National Ice Center, the National Oceanic and Atmospheric Administration (NOAA) CoastWatch Program [Leshkevich et al, 1996], and the NOAA Great Lakes Ice Atlas [Assel, 2003;Wang et al, 2012a] indicate that very cold surface water temperatures and a relatively high areal extent of ice cover persisted across the Great Lakes well into May 2014. (Lake Superior wasn't ice free until 6 June, according to the National Ice Center.)…”

“…[Assel, 2003[Assel, , 2005Wang et al, 2012aWang et al, , 2012b and the NOAA Lake Thermodynamics Model [Croley and Assel, 1994], respectively.…”