Weather Tidbits: Sea Breeze

This edition of Weather Tidbits will discuss the sea breeze. The sea breeze is a cool onshore wind flow that develops at the surface along the coastline during the day. It is formed by the differential heating that is established particularly in the middle of a sunny day. The heating of the ground from the sun causes air to rise. The ocean water will heat up too, though at a much slower rate than the terrain. This results in an area of lower pressure developing on the terrain’s surface relative to the ocean’s surface.

The difference in surface pressure between the water and land then generates an atmospheric circulation as air flows from higher pressure to lower pressure. Thus, an onshore wind develops by the afternoon primarily driven by this differential heating. The opposite effect can happen during the night, known as a land breeze. This occurs when the land cools faster than the ocean, which results in higher pressure relative to the ocean.