The given line graph illustrates the highest percentage of the lake surface covered by ice three of the great lakes from 2000 to 2020.
There is a general trend of similar level in lake superior and lake Michigan. Why lake Eric follow the unique different pattern. However, all of the lake show a short decline after 2015.
Let me begin by describing the lake superior. There is a considerable variation in the ice coverage starting at 40% in 2000 with the high 90% in 2015 and a low 20% in 2020. Meanwhile, the lake Michigan has a lower percentage of ice each year but, the changes are consistent in both lakes. The highest peak around 80% in 2015 and the low fell to 20% in 2020. The greatest difference between the two lakes was in 2005 when the lake superior had 50% coverage and lake michigan had 30%.
By contrast, lake Eric had a completely opposite trend as the maximum amount of ice fluctuated between only from 90% and 95% between 2005 to 2010. After that point, the percentage dropped dramatically to a mear 50% in 2020.