Final answer:
The specific number of square acres of ocean that freeze each winter can't be determined without data for the current year, but the melting of ice sheets has a relation to sea level rise, which is minimal annually but significant over time.
Step-by-step explanation:
The question of how many square acres of the ocean freeze each winter is not straightforward because it varies greatly depending on seasonal conditions and geographic location. However, discussing ocean freeze involves understanding sea level rise due to the melting of ice and the redistribution of this meltwater across the ocean's surface.
If we consider the contributed excess heat and its effect on ice melting, as mentioned in the provided information, roughly 0.1 meters of ice could disappear each year due to 5 x 1020 joules going into the ice annually. Given the vast expanse of the oceans and their comparison to ice-covered areas, the effect on sea level would be minimal annually, though significant over longer periods.
Assessing the potential rise in sea level if all the Greenland and Antarctic ice melted gives us insight into the magnitude of changes we could expect. Complete melting would result in a substantial increase in sea levels, highlighting the link between ice sheets and global sea levels.