Ferrel Cell Definition
Ferrel cell refers to a model that belongs to the mid-latitude region of the Earth’s wind flow. The term was first proposed by William Ferrel in 1856. The air inside the Ferrel cell flows eastward and poleward near the equator and in higher altitude areas westward. It was the first model ever to account for the westerly winds, and the Ferrel cell latitude is between 35o Celsius and 60o Celsius in both the north and south hemispheres. However, the Ferrel cell is not yet considered a perfect representation of reality because it needs the wind to flow westward in the upper level of the mid-latitude.
Hadley Cell and Ferrel Cell
Hadley and Ferrel’s cells are characterized by the current atmospheric energies. There are various weather systems that weave around the globe at the same time. However, if an average is calculated, then the global order of air movement can be estimated.
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Differential Heating
The reason behind so many weather patterns, deserts, jet streams as well as prevailing winds is only because of the circulation of the global atmosphere that is caused due to the Earth’s rotation and the heat that the different parts of the globe receive individually.
Sun is the primary source of heat on the Earth, and as the Earth is in a tilted position, the different regions of the Earth receive heat in different ways. The circulation of wind is caused due to the circulation of Hadley polar and Ferrel cells.
A huge difference in the temperature is experienced due to the difference between the equator and the poles. The global circulation helps in providing inherent air conditioning to stop the poles from becoming too cold and the equator from becoming too hot.
The Global Circulation and its Relation with Polar Cell, Ferrel Cell and Hadley Cell
Vigorous wind circulation covers a significant part of the Earth’s surface. The global circulation is often regarded as a world-wide system of winds necessary to transport the heat from the tropical latitudes to the polar latitudes.
There are three cells in each of the hemispheres, which are named Hadley Ferrel polar cells. The air circulates by the depth of the entire troposphere. The vertical extent of the atmosphere that starts from the surface and then goes directly to the top between 10km to 15km high is known as the troposphere. This is the place in the atmosphere where almost all the weather changes take place.
Hadley cell
Hadley cell refers to the most prominent cell that extends from the equator and goes up to 30 to 40 degrees south and north. It is named after the famous meteorologist named George Hadley. In the Hadley cell, the winds blow towards the equator and then climb near the same place in the form of a broken thunderstorm as a line. This line then forms the Inter-Tropical-Convergence Zone (ITCZ). From the top of the storms, air flows towards the direction of high latitudes. It then sinks into there to produce high-pressure in the Earth’s hottest deserts region and the subtropical oceans, like the Sahara Desert of North Africa.
Ferrel Cell
The middle cell is known as the Ferrel cell, and the air here converges at very low latitude to ascend through the boundaries between the warm tropical air and the cool polar air that appears between 60 to 70 degrees south and north. The Ferrel cell circulation is a mid-latitude circulation that was named by a famous person named Ferrel in the 19th century.
It often takes place across the latitude of the UK that gives unsettled weather to the area. There is a connection between the Hadley cell Ferrel cell. Within the circulation process, air from the Ferrel cell flows at a high latitude and joins the Hadley cell through a sinking air.
Did You Know?
The weakest and the smallest cells are known as the Polar cells.
These extend from 60 to 70 degrees south and north to the poles.
Air in these particular cells sink through the highest latitudes and then flow out to the lower latitude on the surface.
The polar front is the junction that connects the polar cell and the Ferrel cell. This is a low-pressure zone where the relatively warm moist air runs into a relatively dry and cold air of the Polar cell.
So, this is all about the global circulation of winds and their relationship with the polar cell, Hadley Cell and Ferrel Cell. A minute study of the diagrams along with the theoretical part will further clarify your concept of these topics. Practice the diagrams as you read!
FAQs on Ferrel Cell
1. What exactly is a Ferrel Cell and where is it located in the atmosphere?
A Ferrel Cell is a model of air circulation in the Earth's atmosphere for the mid-latitudes. It is located between the Hadley Cell (near the equator) and the Polar Cell (near the poles). Specifically, you can find it between roughly 30° and 60° latitude in both the Northern and Southern Hemispheres.
2. What are the main characteristics of a Ferrel Cell?
The key characteristics of a Ferrel Cell include:
- It is driven by the motion of the neighbouring Hadley and Polar cells, acting like a gear between them.
- Surface winds within this cell are known as the westerlies, which flow from west to east.
- It is considered a thermally indirect cell because it is powered by mechanical forces, not directly by rising warm air and sinking cool air.
- It plays a vital role in transporting heat from equatorial regions towards the poles.
3. How is a Ferrel Cell different from a Hadley Cell?
The main difference lies in how they are powered. The Hadley Cell is thermally direct; it's driven by the sun's heat causing warm air to rise at the equator. In contrast, the Ferrel Cell is thermally indirect. Its circulation is mechanically forced into motion by the adjacent Hadley and Polar cells, rather than being directly caused by temperature differences.
4. What role does the Coriolis effect play in the Ferrel Cell's movement?
The Coriolis effect is essential for the Ferrel Cell's direction. As air moves from the subtropics towards the poles, the Earth's rotation deflects it. This deflection turns the air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, creating the strong westerly winds that are a defining feature of the Ferrel Cell's surface flow.
5. What is the primary function of the Ferrel Cell in our global climate?
The primary function of the Ferrel Cell is to help balance the Earth's temperature. It assists in the global transfer of energy by taking warmer air from the tropics and moving it towards the colder polar regions. This process is crucial for creating the variable weather conditions experienced in the mid-latitudes.
6. Why is the Ferrel Cell called a 'thermally indirect' circulation?
It's called thermally indirect because its circulation doesn't follow the typical pattern of hot air rising and cold air sinking. In a thermally direct cell, like the Hadley Cell, warm air rises. In the Ferrel Cell, however, relatively cooler air rises near 60° latitude, and warmer air sinks near 30° latitude. This is because its motion is mechanically forced by the other cells, not driven by heat.
7. What kind of weather is typically associated with the Ferrel Cell?
The Ferrel Cell is responsible for the highly changeable and often unsettled weather common in regions like Europe and North America. The meeting of cool polar air and warm tropical air creates low-pressure systems, weather fronts, and frequent precipitation, including the formation of cyclonic storms.
8. What would happen to weather in the mid-latitudes if the Ferrel Cell didn't exist?
If the Ferrel Cell were to disappear, the transfer of heat from the equator to the poles would become much less effective. This would likely cause the tropics to become much hotter and the polar regions even colder. The mid-latitudes would lose their dominant westerly winds and the primary mechanism that creates regular storms, leading to a much more extreme and less dynamic climate.
