Which of the following is NOT a factor complicating tidal predictions?

Tidal predictions are influenced by several complex factors, including gravitational interactions and the physical characteristics of the Earth and its oceans. One significant factor is the Earth's irregular mass, which affects the gravitational pull and tidal forces encountered in different locations. Variations in ocean depth also play a crucial role, as the depth can alter the behavior of tidal waves and their velocities.

The distance from the Sun does impact tidal forces to some extent due to the Sun's gravitational influence. However, when looking specifically at factors that complicate predictions, it is the dynamic nature of the biosphere that stands out. This refers to the ever-changing conditions of the environment, including coastal developments, weather patterns, and anthropogenic impacts, which can complicate the computation of precise tidal predictions, unlike the more predictable factors.

Therefore, the focus on the distance from the Sun highlights that, while it influences tides, it is not as directly involved in the complex and variable factors that challenge tidal predictions in the same way as Earth's mass irregularities and ocean depth variations do.