Final answer:
High precipitation around the equator results in water that is less salty because the rain dilutes the saline contents of surface waters.
Step-by-step explanation:
Right around the equator, precipitation is high making water less salty. This is because as rain falls, it dilutes the salt in the bodies of water it enters, such as lakes and rivers, which typically have lower salinity levels compared to the ocean. Precipitation acts as a key component in the water cycle by redistributing fresh water across the planet. In equatorial regions, the sun heats the air, causing it to rise and cool, which leads to high levels of precipitation. This high rainfall contributes to the dilution of salt in surface waters, resulting in a decrease in salinity. Conversely, regions around 30 degrees north and south latitude usually experience drier conditions and less precipitation, which can lead to higher salinity levels in isolated water bodies, due to less dilution and increased evaporation.