*Please refer to my “Terms & Concepts” page for more definitions and topics*
Sea breezes occur during the day, near the coast of a big body of water, as a result of daytime heating. From the United States perspective, the body of water doesn’t necessarily have to be from an ocean or from the Gulf of Mexico, big lakes can produce sea breezes, too.
In order to understand how sea breezes are generated, you must know what specific heat is and the difference between the specific heat of soil (land) versus the specific heat of water.
Specific Heat: The amount of heat per unit mass required to raise the temperature by 1 degree Celsius.
This definition is important because every single thing that has a mass on Earth has a unique specific heat. Meaning, it takes some things longer to heat up than other things. This is very important to understand because sands and soils heat up much faster than water does. I won’t go into specifics as to what kind of soils and what kind of water there are out there. For educational and informational purposes, the specific heat of water is approximately 5 times greater than the specific heat of land. This means that it takes water longer to heat up 1 degree Celsius than it does land. A temperature gradient is formed as a result of daytime heating. The difference in the temperatures also creates low pressure and high pressure. However, this isn’t like your typical high and low pressures you see on national weather maps, they don’t have quite the intensity and are barely measurable. The pressure differences are enough to create a “cylce-like” process.
As the sun heats the dry land, low pressure forms and the air begins to destabilize, then rise. The air rises high enough to cool down and form clouds and sometimes even precipitation (sea breeze shower). High pressure is formed aloft, above land because heights are raised from the rising air. In the northern hemisphere, air advects from high pressure to low pressure. Air sinks back down because it is cooler than its environment. At the surface, wind causes an outflow boundary to advect moisture towards land and the cycle continues until the sun’s energy is gone. Below, is a diagram that depicts the sea breeze process, in case you got lost: