Sea breezes and I’m not talking about the ones with cranberry juice are onshore localized winds that occur regularly at and near the coastal areas.
These winds are driven by differential heating of the land near a large body of water.
Sea breezes will blow onshore during the day and reverse becoming a land breeze in the evening and night. These winds are more localized than the prevailing winds and have different impacts.
So what causes this localized wind pattern?
During the day the sun adds energy to the ocean and the land which heats them up. Areas onshore will heat up much faster than the ocean surface and a temperature gradient is set up between the ocean and land. The warmer air located over the land mass will rise during the day creating low pressure at the surface. Over water higher pressure will form due to the relatively cooler air in place and air over the water will sink. This is the set up for a sea breeze as the wind will blow from high pressure over the ocean to the low pressure set up on land. The strength of the sea breeze will vary depending on the temperature gradient between the land and water.
At night we see the winds reverse direction and blow from the land to the water and this is known as a land breeze. Once the daytime heating has dropped off the land mass will cool much quicker than the oceans, reversing the temperature gradient and the wind direction. At night there is lower pressure over the ocean due to warmer temperatures and higher pressure over land due to cooler temperature there.
Sea breezes are cooler than the air they replace, so for hot coastal regions they are a welcomed daily event.
The cooler sea breeze will also do a good job keeping bugs away from the beach during the day but they will return on the land breeze in the evening so keep that repellent handy.
Sea breezes can initiate thunderstorm development near the coast and migrate these storms inland during the day. This happens plenty during the summer months especially along the Gulf Coast and Florida.
In places like the Texas coast the sea breeze is consistently strong on a daily basis during the summertime and because of that, kite boarding has become more popular in places like Corpus Christi, Texas.