Lake Michigan, the fifth largest lake in the world, has an interesting relationship with winter temperatures. Depending on the season, its level of ice cover can range from practically zero to nearly completely frozen over. While the lake sees significantly cooler temperatures in the winter than the summer, much of the impact comes from the frequency of cold snaps and ice storms that drastically drop the temperature.
Overall, climatologists report that Lake Michigan maintains a steady average temperature of 40 degrees Fahrenheit throughout the winter, which is almost 10 degrees higher than its freezing point. This explains why the lake’s shorelines regularly experience flash-freezing events, where sections of the shoreline freeze overnight. Technically, this means little to no overall ice coverage of the lake itself.
However, every few years scientists report a significant event involving a prolonged period of ice coverage known as the “Great Lakes Freezing Experiment.” During this experiment, a combination of atmospheric cooling and strong winds (from the north and east) cause a permanent ice sheet up to an inch thick to form across the surface of the lake. This sheet often lasts for weeks or even months, and it’s what scientists use to monitor and gauge the health of the Great Lakes.
But how much of the lake is typically frozen during the experiment? Estimates vary, but the most recent data suggest that the lake is officially frozen over almost 19% of the time. The majority of this snow and ice (around 16%) shows up on the northern and western edges of the lake. This has been the overall average for the past few years now, and it’s unlikely to change anytime soon.
Interestingly, researchers have found that the strength of the lake’s ice cover is affected by a number of factors, including lake levels, wind speed and direction, surface temperature, and even human activity.
For instance, warmer water encourages more evaporation, which can lead to a decrease in lake levels and a reduction in ice cover. Similarly, strong winds tend to blow away chunks of the ice, making it less able to fully cover the lake once the colder temperatures return.
Humans also play a role in affecting the lake’s ice cover. Air pollution, industrial runoff, and various other forms of human pollution destabilize the lake’s ecosystem, which can lead to earlier melting or reduced snowfall. Increased shipping and boat traffic also contribute to the lake’s ice cover in a variety of ways, whether it’s through waves knocking chunks of ice off or melting the snow on the surface.
Impact of the Ice Cover on People
The degree of ice on Lake Michigan can have a major impact on local communities. For instance, during ice storms, many communities and their infrastructure, such as power lines, are at risk of exposure to extremely low temperatures and potential damage due to the freezing weather.
Additionally, ice chunks that form on the surface of Lake Michigan can also damage boats and other recreational vessels, as well as impede navigation. In extreme cold snaps, Lake Michigan can be hazardous for fishermen, where the waves create strong undertows that can pull boats and anglers underwater.
Impact of the Ice Cover on Nature
Lake Michigan plays an important role in the Midwest’s aquatic ecosystem, not only in terms of the variety of species that inhabit the lake, but also in terms of the larger aquatic food web. The rapid freezing and thawing of the lake’s surface each winter affects not only the fish that depend on a certain temperature range, but also the various insects, plants, and other organisms present in or near the lake.
In addition, the lake’s ice cover can help protect some species from predation and fishing during the winter months. For example, during winter, many of Lake Michigan’s geese, ducks, and other waterfowl take advantage of the ice-covered water to find adequate shelter from predators.
In many ways, the lake’s ice cover also aids in keeping the lake’s water levels in balance. As the surface water cools and freezes, the lake’s deeper warm waters are prevented from evaporating as rapidly, which helps maintain the lake’s equilibrium.
Ice Coveras a Measure of Global Warming
Unsurprisingly, the ice cover of Lake Michigan also serves as a key indicator of global warming. As temperatures on the lake consistently rise, scientists are noticing a decrease in ice cover from year-to-year. Of course, these effects are also impacted by natural fluctuations in precipitation and air temperature, but the overall trend cannot be ignored. In fact, some climatologists believe that the lake could see a 50 percent decrease in ice coverage by the end of the century.
These drastic changes could have a profound impact on the lake’s various inhabitants, including fish, waterfowl, and other species. As the lake becomes increasingly warmer and less ice-covered, it’s likely that some species will go extinct while others will change their behavior in order to adapt to the changing environment.
Rise in Temperatures Effects on Lake Ice Coverage
Increased temperatures due to climate change are affecting lake ice coverage in a number of ways. Warmer temperatures mean more snow and ice melting, leading to a decrease in the overall ice cover of the lake. Warmer water also leads to an increase in evaporation, which reduces the overall lake levels and further impacting the distribution and stability of the lake’s ice.
Additionally, higher temperatures mean that more boat traffic can occur in and around the lake during the winter. This contributes to the lake’s ice loss due to the melting effect of boat propellers, as well as the introduction of pollutants into the lake and surrounding environment.
Finally, higher temperatures can impact the weather patterns of the lake’s surrounding areas, increasing the prevalence of rain and snow storms that can cause flash-freezing events, drastically drop in temperature, and reduce the lake’s ice cover.
Visitors Impact on the Ice Cover
Despite recent advances in forecasting and monitoring technologies, Lake Michigan’s ice cover is still difficult to predict. Every winter, families and visitors flock to the beaches to see the majestic ice formations on the lake’s shoreline and the unique landscape that ice creates. While this is a great opportunity for people to take in the beauty of the lake, it can be dangerous, as the lake’s water temperature, ice thickness, and waves can change unpredictably.
Additionally, visitors can unintentionally contribute to Lake Michigan’s ice loss by releasing pollutants into the water or creating wakes that can further weaken existing ice. Therefore, it’s important for visitors to obey local regulations and to be mindful of their actions when visiting the lake during colder months.
Conclusion
In general, Lake Michigan’s ice cover is dependent on several factors. While the lake’s average temperature stays fairly constant throughout the winter, strong winter storms and the impact of human activity can significantly affect the amount of ice on the lake’s surface. As the impact of global warming becomes more pronounced, it’s likely that Lake Michigan’s ice cover will continue to decrease in the future. As with any other natural phenomenon, visitors must be mindful and respectful of the lake during the winter months to ensure its sustainable preservation.
