Final answer:
The annual range of surface temperature over the land is greater than over the ocean in the Northern Hemisphere's middle latitudes due to the land's lower heat capacity compared to water.
Step-by-step explanation:
The annual range of surface temperature over land is greater than over the ocean in the Northern Hemisphere at middle latitudes. Land heats up and cools down more quickly due to its lower heat capacity compared to water. Thus, land areas exhibit higher temperature variability between summer and winter.
Oceans, on the other hand, have a higher heat capacity, which means they absorb and retain heat for longer periods, leading to a much more moderate temperature range across the year.
This is often referred to as the moderating influence of the oceans on climatic ranges, which results in milder winters and cooler summers near coastal regions than areas further inland at similar latitudes.