Which type of fog forms when wind heated by warm ocean water blows over cool ocean water?

Which type of fog forms when wind heated by warm ocean water blows over cool ocean water?

• A. Sea fog
• B. Radiation fog
• C. Upslope fog
• D. Advection fog

Answer: (A)

Fog forms when moist air cools to its dew point, causing water vapor to condense. When warm, moisture-rich air moves horizontally over a surface that is cooler than the air, the air cools to its dew point near the surface and a veil of fog forms. Over the ocean, this is called sea fog because it happens above the sea surface. The scenario you described—air warmed by warm ocean water moving over cooler ocean water—matches this process, producing sea fog. Radiation fog would require ground cooling at night, upslope fog forms as air rises up terrain, and that’s not the situation here.

Fog forms when moist air cools to its dew point, causing water vapor to condense. When warm, moisture-rich air moves horizontally over a surface that is cooler than the air, the air cools to its dew point near the surface and a veil of fog forms. Over the ocean, this is called sea fog because it happens above the sea surface. The scenario you described—air warmed by warm ocean water moving over cooler ocean water—matches this process, producing sea fog. Radiation fog would require ground cooling at night, upslope fog forms as air rises up terrain, and that’s not the situation here.