Everyone loves a hot, sunny day at the beach. Although the sun might be shining, one must never fall under the illusion that a sunny day at the beach always means that it’s going to be a warm day. Beaches are usually much colder during the day than one might think.
Beaches are colder than inland areas because the ocean has a much higher heat capacity than land. Due to the varying heat capacities, different air pressures are created over the ocean and the land. This causes a wind known as a “sea breeze,” which causes beaches to be colder than inland areas.
To truly understand why it’s colder at the beach than inland areas during the day, one must first understand what causes the weather phenomenon known as a “sea breeze.” However, it is also important to note that the beach tends to be warmer during the night than inland areas due to a weather phenomenon known as a “land breeze.”
Why It Is Colder At The Beach
Sea water has a very high heat capacity, unlike land, which has a relatively low heat capacity. This high heat capacity means the seawater can absorb and lose much more quickly than the land. Due to the sea water’s ability to absorb heat so rapidly, when the sun rises in the morning, the seawater quickly rises in temperature above that of the land.
This rapid rise in the temperature of the seawater triggers the formation of a wind known as a “sea breeze,” which is responsible for the beach being colder than inland areas.
How Is A Sea Breeze Formed?
A “sea breeze” is a wind that blows from the oceans to inland areas during the day. A few factors contribute to the formation of this wind, including the heat capacity of the water in the ocean and of the soil and rocks inland, as well as the air temperature and pressure of the air above the ocean and the land.
When Does A Sea Breeze Occur?
A sea breeze begins when the sun starts to rise in the morning and ends at sunset. This is because the sun provides heat that can be absorbed by the land and ocean water. The heat absorption causes temperature fluctuations in both the surface of the ocean and the land. The rapid rise in the land’s temperature triggers climatic conditions, which cause a sea breeze to begin.
The Difference In Heating Capacities Of Oceans And Land
Heating capacity is the amount of heat it takes for something to change its temperature by a single unit. In this case, it’s the amount of heat from the sun that it takes for the ocean water or the rocks and soil from the land to change its temperature by a single degree.
During the day, the ocean absorbs the heat from the sun. The ocean is a body of water that has a high heating capacity. The high heating capacity means that the water will take a relatively long time to change in temperature. This means that the water’s surface will be cooler in temperature than the land.
On the other hand, the land is made up of rocks and soil, which have a lower heating capacity than water. The low heating capacity of the land allows it to absorb heat from the sun faster during the day than the ocean does. This means that the temperature of the land will take a much shorter time to increase than that of the ocean, resulting in the land temperature being warmer during the day.
Air Temperature And Pressure Differences Of Oceans And Land
The ocean’s high heat capacity means that the water’s actual temperature is cooler during the day, meaning that the air above the ocean is cooler and will sink. This cool air sinking results in a high air pressure being created above the ocean.
The low heat capacity of the land, however, means that the temperature of the land itself is much warmer than the ocean during the day. This means that the air above the ground is warmer and rises, resulting in a low air pressure created above the inland areas.
The difference in air temperatures over the air and the land causes a resultant “cross-shore” air pressure gradient. Air flows from high pressure to low pressure, which creates wind. This wind, known as a “sea breeze,” is then developed because of the cool air (high pressure) above the ocean flowing to the warmer air (low pressure) inland because of the cross-shore pressure gradient.
This “sea breeze” phenomenon causes the temperature at the beach to be colder than inland areas during the day. When the sun sets, however, the temperature of the land rapidly cools down due to the absence of heat. The decrease in temperature of the land below that of the surface of the water of the ocean then triggers the sea breeze to stop and a land breeze to begin.
What Is A Land Breeze?
A “land breeze” is a wind that flows from the land to large bodies of water such as the ocean during the night. The land breeze is the opposite counterpart weather phenomenon to the sea breeze.
When Does A Land Breeze Occur, And How Is It Formed?
When the sun sets, the ocean water’s surface is warmer than the land. This is because the heating capacity of the land is lower than the heating capacity of the ocean. This means that the temperature of the land will begin to drop faster than that of the ocean when the heat from the sun becomes absent at sunset.
Due to the warmer temperature of the ocean, the air above the ocean is warmer and therefore rises. This creates a low air pressure over the ocean. The land, on the other hand, rapidly having cooled down, has a cooler temperature; therefore, the air above it is cooler and sinks. This results in a high air pressure being created above the land.
The cross-shore pressure gradient created results in the air flowing from the land (high air pressure) towards the ocean (low air pressure). The airflow created from this movement results in the wind known as a “land breeze.”
The land breeze ends at sunrise, when the sun’s heat starts to be rapidly absorbed by the land, causing the temperature of the land to become warmer than that of the sea. This rapid increase in the temperature of the land then triggers the sea breeze to begin.
Conclusion
The beach is colder than inland areas due to a range of factors. These factors include the heat capacity of both water and soil or rocks, air pressure gradients, and air temperatures above the land and the ocean.
The high heating capacity of the ocean causes cool, high-pressure air to form above it. The land has a lower heating capacity than water, resulting in warmer, low-pressure air forming above it. The resultant “cross-shore” air pressure gradient causes air to flow from the ocean to the land, which causes a wind known as a “sea breeze.” This causes beaches to be colder than inland areas.
References
- https://whyy.org/articles/why-beaches-are-usually-cooler-during-heat-wave-afternoons/
- https://www.actionnews5.com/2020/09/18/breakdown-sea-breeze-why-it-makes-waterfront-feel-cooler/
- https://www.wtnh.com/news/why-is-it-so-much-colder-at-the-beach/
- https://er.jsc.nasa.gov/seh/Ocean_Planet/activities/ts1ssac3.pdf
- https://943thepoint.com/heres-why-its-literally-cooler-at-the-shore/
- https://www.thoughtco.com/what-is-a-land-breeze-3444017
- https://www.encyclopedia.com/earth-and-environment/ecology-and-environmentalism/environmental-studies/land-and-sea-breezes
