Final answer:
The upper part of the water column affected by wind is called the mixing zone, where water layers mix due to turbulence caused by the wind.
Step-by-step explanation:
The upper part of the water column that is affected by the wind is called the mixing zone.
In this zone, the wind causes turbulence, leading to the mixing of water layers. This mixing zone is significant as it plays a crucial role in the distribution of heat, nutrients, and oxygen in the water column.
For example, in the mixing zone, warmer surface water can mix with cooler water from deeper layers, affecting the overall temperature and density of the water column.
Learn more about Water column mixing due to wind