[Physics Class Notes] on Sea Breeze Pdf for Exam

One can describe sea breeze as a wind system that is localized. The sea breeze definition can be stated as the characteristic wind flow that takes place from sea to land, usually during the day. It is also called the onshore breeze. To describe sea breeze formation we have to focus on the pressure difference which is created by different heat capacities of water and lands that are dry. Apart from the sea breeze, a land breeze is also observed. Sea breeze usually moves from large bodies of water towards landmasses. The difference between the sea breeze and the prevailing winds is that the sea breeze is more localized.

What is Sea Breeze?

To understand what is sea breeze, we first have to understand how breezes are formed. Breeze is usually described as a moderate air current. It is gentle and light. The temperature gradient of any type results in the formation of a breeze. Breezes of two types- sea breeze and land breeze. They vary information and also their direction of flow. The sea breeze definition says that sea breeze is a type of wind that flows from the inland of the ocean to the landmass. Since this breeze originates in water bodies, thus it is called sea breeze.

Sea Breeze – Origin and Characteristics

We all know that during the daytime the ocean and the land both get heated up. Now since water absorbs heat better than landmass, water absorbs heat much more slowly than land. As a result, the air above the land gets heated up quickly during the daytime. The phenomenon involved in this heating is called convection. Now as the air above the land gets heated up during the daytime, it starts expanding. As the air above the land expands it becomes less dense. The air above the land now has lesser pressure compared to the air above the waterbody. Now air starts flowing from a region of higher pressure to a region of lower pressure. This is how does sea breeze occur when the air starts flowing from the waterbody toward the landmass.

Sea breeze occurs during the daytime. During spring and the months of summer is the time when does sea breeze occur mostly. The sea breeze can be very soothing. People who live near the coast can experience this gentle breeze. Usually, people who live within a 30-40km distance of the coast experience winds during the daytime with a speed of 10 to 20km per hour which are caused due to sea breeze.

Sea Breeze and Land Breeze Activity

The sea breeze and land breeze activity differ in origin, movement and time of formation. Sea breeze occurs during daytime and land breeze occurs during the night. Sea breeze originates over the water body whereas land breeze occurs over the landmass. Landmass loses heat more quickly than waterbody. As a result, soon after sunset the sea breeze dies away and the land breeze is formed. Land breeze is also called offshore breeze. At night, the pressure over the land is higher than the pressure over the waterbody. As a result, now wind flows from the land towards the waterbody.

Did You Know?

1. The nature and strength of the sea breeze bear a direct relationship with the temperature difference between landmass and waterbody. The temperature difference between landmass and waterbody results in a pressure difference due to the expansion of the air layer. Sea breeze mostly occurs in the spring and summer months. This is because during this time the temperature difference is maximum due to unequal heating from sun rays in the afternoon. 

2. To describe sea breeze, we can say that these breezes are moderate. They are gentle. They bring fair weather. The fair weather is often accompanied by drizzles. However, from the sea breeze definition, it can also be inferred that due to the presence of strong winds which flow offshore. Strong winds with a speed of more than 15km/h can subdue the effect of sea breeze.

Conclusion

In the coastal region, it is seen that sea breezes generally alternate with land breezes. This takes place largely in absence of strong winds. This is supported by strong heating during the daytime and strong cooling is needed during nighttime. It is observed that a low-level convergence of air is produced as the sea breeze and its surface flow gets terminated over land. This kind of convergence results in the development and formation of clouds. Such formation of clouds results in rainfall during the daytime.