Final answer:
When latitude increases, sunlight becomes less direct. The polar zone is colder than the tropical zone because it receives more indirect sunlight. The density of ocean water is affected by factors such as salinity and temperature.
Step-by-step explanation:
When latitude increases, sunlight becomes less direct. The earth is tilted on its axis, so as it rotates around the sun, the angle of direct sunlight on the planet varies. Places at higher latitudes receive sunlight at a steeper angle, which results in more reflected sunlight and a cooler climate.
The polar zone is colder than the tropical zone because it receives more indirect sunlight. In the polar zone, the angle of sunlight is lower, causing sunlight to spread over a larger area and resulting in less warming. In contrast, the tropical zone receives more direct sunlight, which leads to a warmer climate.
The density of ocean water is affected by factors such as salinity and temperature. Differences in salinity cause differences in density, but temperature also plays a role. Warmer water tends to be less dense than cooler water. Therefore, changes in temperature can affect the density of ocean water.