[Physics Class Notes] on Types of Wind Pdf for Exam

The wind is the movement of air caused by differences in pressure in the atmosphere. In order to balance the differences in air pressure, wind flows from the high to the low air pressure region. In addition, the greater the pressure difference, the faster the wind flows.

Generally, there are three types of winds on earth:

• Primary Wind

• Secondary Wind

• Tertiary Wind

Periodicity and location of occurrence are factors considered in this classification.

Primary Wind or Planetary Wind

Throughout the year, certain winds continuously blow in a particular direction. Prevailing winds and planetary winds are also referred to as primary winds. A trade wind, westerly wind, and easterly wind are three types of primary winds.

Secondary Wind or Periodic Wind

A secondary wind changes direction according to the season. Other names for secondary winds include seasonal winds and periodic winds. This phenomenon occurs in many different places around the world. Based on the particular geographical location, a secondary wind is generated and the physical forces driving it. A monsoon wind is recognizable as one of the secondary winds.

Tertiary Wind or Local Wind

There is only one Tertiary wind in a small area for a particular part of the day or year. Different temperatures and air pressure at different locations lead to these winds. There are different types of wind based on local characteristics, such as hot, cold, ice-filled, dust-filled, etc. A Loo is a hot and dry wind found primarily in the northern plains of India. In addition to Mistral and Foehn, other local winds include Bora, Foehn, and others.

The Different Types of Wind

Trade Winds

Tropical easterlies are also called trade winds and are found in both the Northern and Southern hemispheres thanks to the Coriolis effect and Ferrel’s law. Subtropical high-pressure areas start blowing towards the equatorial low-pressure belt. The trade winds blow northeast in the Northern Hemisphere, and southeastern in the Southern Hemisphere.

The Westerlies

These winds are also referred to as the Roaring Forties, the Roaring Fifties, and the Shrieking Sixties. Unlike the subtropical high-pressure belt, the subpolar low-pressure belt blows from the subtropical high-pressure belt. Westerlies occur more frequently and consistently in the Southern hemisphere than in the Northern hemisphere.

Polar Easterlies

The Polar easterlies are cold, dry winds with a directional movement in both the Northern and Southern Hemispheres. They blow south-east to the north-west on a constant basis in both hemispheres. Subpolar low-pressure zones produce easterly winds.

Monsoon Winds

During low-latitude climates, monsoons are wind patterns that frequently change directions between summer and winter. A monsoon normally occurs in winter when moisture flows from the land to the sea and in summer when water flows from the sea to the land, resulting in a drastic change in the climate and precipitation patterns in the monsoon-affected areas. In the Indian subcontinent, the monsoon is caused by variations in temperature caused by the Indian Ocean, Arabian Sea, Bay of Bengal and Himalayan wall.

Land Breeze and Sea Breeze

An area of land breeze can be described as a region in which winds blow from land to sea without carrying any moisture. Rather, the sea breeze brings moisture to the land when it blows from the sea to the land. Warm, dry land breezes accompany the sea breezes.

Mountain and Valley Breeze

The air fills the gap created by the warming of the slopes during the daytime in mountainous regions. Such a wind is referred to as the valley breeze. A mountain breeze descends from the slopes into the valley during the night as the slopes cool.

Local Winds

Depending on the local pressure and temperature differences, local winds occur. However, these winds tend to occur in the lowest levels of the troposphere. Loo, Bora, Chinook, and Zonda are examples of local winds that are discussed.