Introduction
The wind is the movement of air from a high-pressure area to a low-pressure area or in another way from a parallel or horizontal direction. It forms because of the distribution of heat on the earth’s surface. There are four types of winds namely planetary wind, periodical wind, local wind, and sudden or irregular wind. Land and sea breezes are the types of periodical wind. Let’s discuss the difference between land and sea breeze.
The balance of air pressure on the earth’s surface is maintained by the wind. Wind also plays an important role in maintaining global temperature balance. The nature of wind is that it flows from a warmer place to a cooler place or as we said earlier from the high-pressure area to the low-pressure area.
The balance of air pressure on the earth’s surface is maintained by the wind. When it is excessive, it produces cyclones on land and tidal waves in the sea. So wind plays a great role on the earth’s surface. There are various types of wind. Land and sea breeze are some of them (1) & (2).
Land breeze and how they form
Formation of Land breeze
From the time of sunset, the land radiates heat and gradually cools. When the air above the land cools down like the air above the seawater, the sea airflow stops. But at night the body of water stays warm because it cannot heat up as fast as the land. Thus the air pressure at sea level is lower than the air pressure at land. As a result, at night, the wind blows faster from the land to the water and is called land breeze (1).
How land breeze form
The wind in a coastal area usually depends on the difference between the daytime and nighttime temperatures on land and sea. During the day the sun’s rays fall evenly on the sea and on the land. Due to the natural differences, the land heats up faster than the sea.
The heated land gradually radiates heat and cools down in the evening. In this case, the wind coming from the sea also gradually stopped. The seawater stays relatively warm at night as it cannot radiate heat faster than land.
As a result, when the air above the body of seawater becomes warm, expands, and becomes lighter, the air pressure there decreases. But then the wind above the land surface is relatively cool and high pressure.
As a result, the air flows from the land to the vacuum created by the low pressure of the seawater. This is how the land breeze formed (3).
Effect of the land breeze
The effect of land breeze is seen over an area of about 10- 15 km in land from the coast.
Interesting facts about the land breeze
1. Velocity is approximately 5 to 10 km/hr.
2. These breezes are limited to about 2 km perpendicular to the atmosphere.
3. This type of wind has less water vapor because it is formed from land.
4. Although it has been flowing since evening, the land breeze has been relatively strong from midnight to dawn.
5. This wind is heated over the sea, rises upwards, flows in the opposite direction, and returns to land.
6. The land breeze flows from land to sea.
7. When the land breeze is flowing, the presence of low pressure in the sea and high pressure in the land is observed.
8. It usually flows more in winter (1).
Example of the land breeze
Most of the coastal breeze blows in the night from the land to the sea.
The sea breeze and how they form
Sea breeze
The land can heat up faster than the sea. For this reason, when the sun’s rays fall on the earth’s surface during the day, low pressure is created due to the warming of the land of the sea coast. Then the sea wind rushes towards low pressure on land. As the day progresses, the speed of this wind increases. This air is called sea breeze (1) & (2).
How they form
The air in a coastal area usually depends on the difference between daytime and nighttime temperatures on land and sea. Although the sun’s rays fall evenly on the sea and land during the day, the land warms up faster than the sea due to natural differences.
The land cools faster than the sea at night. So during the day, the heat of the sun warms the land near the sea more than the water of the sea and the air above the land warms, expands, and becomes lighter. As this light air rises, the air pressure there decreases. But then the air above the sea is relatively cool and high pressure. This causes air to flow from the sea to the land. As a result, the sea breeze originates (1) & (2).
Affected areas of sea breeze
In the tropics, the effect of the sea breeze is more than 40 to 50 km in land from the coast, and in the temperate zone, it is more than 15 to 5 km in land from the coast.
Interesting facts about the sea breeze
1. The wind that blows locally from the sea towards the land is called the sea breeze.
2. Sea breezes are usually seen in the morning and evening.
3. This type of breeze is humid because it comes from the sea.
4. When this wind blows, there is high pressure on the sea and low pressure on the land.
5. In spring and summer, the flow of the sea breeze is more noticeable.
6. Sea breeze speeds of 10 to 20 knots are accomplished (1).
Example of sea breeze
The gentle south wind that blows in the summer afternoon or evening in the districts adjoining the Bay of Bengal is the sea breeze from the south sea.
Differences between land and sea breeze
Winds that blow temporarily at different times of the day or in different seasons are called periodical winds. One of these periodical winds is the sea breeze and land breeze, which flow at certain times of the day. The differences between land and sea breeze are discussed below.
Content |
Land breeze |
Sea breeze |
| 1. Definition | This type of breeze flows from land to sea due to the difference in temperature at night. The sea stays warm at night thus causing a low pressure compared to land.
As a result, air flows from land to sea. This air is known as a land breeze. |
As the name suggests the wind or breeze from sea to land is known as a sea breeze.
During the day the land heats up faster than the sea. Thus forming a low air pressure. Hence air flows from sea to land. |
| 2. Flow time | It mainly flows from midnight to dawn. | Sea breezes are usually seen in the morning and evening. |
| 3. Type of wind | As the land breeze flows from the land surface, there is no water vapor in this air. So the land breeze is dry. | The sea breeze is humid because it comes from the sea. |
| 4. Direction of airflow | The land breeze flows from land to sea. | Sea breeze flows from the sea to the land. |
| 5. Position of air pressure | The presence of low pressure in the sea and high pressure in the land is seen when the land breeze is flowing. | When the sea breeze flows, there is high pressure on the sea and low pressure on the land. |
| 6. Seasonal time | Usually flows more in winter and autumn. | In spring and summer, the flow of the sea breeze is more noticeable. |
| 7. Depth | This is shallow. | The sea breeze is deep. |
| 8. Air type | It is a weak breeze. | It is stronger than the land breeze. |
| 9. Speed | A land breeze moves at a slower speed, 8 to 10 knots. | Sea breeze moves faster than a land breeze, i.e., 20 to 25 knots. |
| 10. Influencing the temperature | It does not affect temperature. | Temperature is influenced by a sea breeze. It makes the temperature low. |
| 11. Other names | Also is known as off-shore wind. | A sea breeze is called on-shore wind (1) & (2). |
Similarities
- Sea and land both breeze have an effect on the atmospheric temperature, precipitation rates, and humidity levels.
- Both breezes occur near the coastal area.
- Due to the land and sea breeze, there is not much difference in temperature near the sea or in the coastal area (1) & (3).
Q&A
1. What is a land breeze?
At night, the land is cooler than the sea. So high pressure prevails on the land. Then the wind blows from the land towards the sea. This wind is called land breeze (1).
2. What causes land and sea breezes?
Causes of the land breeze
At night, the temperature of the air above the sea is warmer than the temperature of the air above land. The air above sea moves upwards. And the air from the land moves in, creating the land breeze (1) & (3).
Causes of sea breeze
As soon as the land is heated, the sea cannot be heated. As the land warms, the air layer adjacent to the earth’s surface becomes warmer and lighter. Then this air layer rises and causes depression.
Meanwhile, the sea is still cool, so there is high pressure on the sea.
Then the air flows from the high-pressure area to the low-pressure area. This air is a sea breeze. The primary causes of sea breeze are the low pressure present in the land and high pressure present in the sea. So the wind blows faster from high pressure to low pressure (1) & (3).
3. What causes land breezes and sea breezes?
The main causes of land breeze flow are high pressure on land and low pressure on the sea. From the time of sunset, the land radiates heat and gradually cools. When the air above the land cools down like the air above the seawater, the sea airflow stops. But at night the body of water stays warm because it cannot heat up as fast as the land. The air pressure at sea level is lower and the air pressure at land is higher. As a result, at night, the land breeze flows (1) & (2).
Whereas sea breeze flows is low pressure on land and high pressure on the sea. Lands can heat up faster than the sea, and it heats up faster. For this reason, when the sun’s rays fall on the earth’s surface during the day, low pressure is created due to the warming of the land of the sea coast. Then the sea breeze rushes towards low pressure on land (1) & (2).
4. What causes sea breezes and land breezes?
The primary causes of sea breeze flow are low pressure on land and high pressure on the sea. Sea breeze flows from the sea to the land. The main causes of land breeze flow are high pressure on land and low pressure on the sea.
5. How do land and sea breezes form?
Formation of the land breeze
From the time of sunset, the land radiates heat and gradually cools. When the air above the surface of the land cools down like the air above the sea, the flow of sea air stops. But at night the sea cannot radiate heat as fast as land.
So the sea stays warm. This causes low air pressure to be created over the sea. And then there is high pressure on the ground. As a result, air flows from land to sea. In this way, a land breeze is formed (1) & (2).
Formation of sea breeze
During the day the sun’s rays fall evenly on the sea and land. But due to natural differences, land heats up faster than the sea. On the other hand, the land cools faster than the sea at night. As a result, the air in the land warms and expands during the day and rises. And there is low air pressure created. But then there is a relatively cool and high pressure on the sea. So air flows from sea to land. In this way, the sea breeze is formed (1) & (2).
6. How do sea breezes and land breezes form?
Sea breeze
The air in a coastal area usually depends on the difference between daytime and nighttime temperatures on land and sea. Although the sun’s rays fall evenly on the sea and land during the day, the land warms up faster than the sea due to natural differences.
So during the day, the heat of the sun warms the land near the sea more than the water of the sea and the air above the land warms, expands, and becomes lighter. As this light air rises, the air pressure there decreases. But then the air above the sea is relatively cool and high pressure. This causes air to flow from the sea to the land. As a result, a sea breeze is formed (1) & (2).
Formation of Land breeze
From the time of sunset, the land radiates heat and gradually cools. When the air above the surface of the land cools down like the air above the sea, the flow of sea air stops. But at night the sea cannot radiate heat as fast as land. So the sea stays warm. This causes low air pressure to be created over the sea. And then there is high pressure on the ground. As a result, air flows from land to sea. In this way, a land breeze is formed (1) & (2).
Written By: Manisha Bharati
Reference
1. Savindra Singh. Climatology. Pravalika Publications, Allahabad. Chapter 7: Local and seasonal winds. Page No: 118 to 121.
