How would the weather be affected if the oceans were fresh instead of salty?

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Dear Tom,
How do you think the weather would be affected if the oceans were fresh instead of salty?
Jim Weber, Cary
Dear Jim,
No effect. Oceans affect the weather in two ways: Water evaporates from the oceans’ surface and is released into the atmosphere. This means air over the oceans is rather moist. When ocean air moves over land and is lifted, it cools and, if cooled to the point of saturation, it condenses into clouds and fog, which leads to precipitation. The Earth’s wettest climates occur where onshore winds blow into mountainous areas.
Also, ocean air tends toward the temperature of the ocean itself. This means it is relatively cool in the world’s tropical areas and northward and southward, where inland temperatures can be high. In far northern and southern regions of the planet, it’s opposite: Ocean air is relatively mild and imparts that warmth to oceanic land locations.

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