Final answer:
The above-normal snow cover extent in the Northern Hemisphere during the 2009 and 2010 snow seasons may be linked to natural climatic cycles such as the Milankovitch cycles, as well as to the increasing extremity of weather events leading to higher precipitation in some regions.
Step-by-step explanation:
The student is asking about the reasons for above-normal snow cover extent during the 2009 and 2010 snow seasons in the Northern Hemisphere, which may be a result of a climatic pattern that was not stipulated in the question but could be hypothetically linked to the newly hypothesized phenomenon. One possible explanation for the increase in snow cover could relate to the Milankovitch cycles, which describe the changes in Earth's movements and their impact on the climate over thousands of years. Another plausible factor could involve the observed variations in weather extremes, such as increased precipitation in some high latitude regions, which is supported by climate models and historical climate records like the Little Ice Age.
Throughout Earth's history, there have been periods of significant climate change, including ice ages and inter-glacial periods. These are documented through geological evidences which demonstrate substantial shifts in temperature, precipitation, and ice coverage. The dynamics of Earth's axial tilt and its effect on the distribution of sunlight over the planet can also influence the intensity of seasons, further impacting snowfall and climate patterns.
Climate changes, including shifts in precipitation and storm events, are complex and often influenced by a variety of factors. These include natural cycles such as the Milankovitch cycles, human-induced climate change leading to more extreme weather events, and other documented shifts like those during the Little Ice Age.