The natural movement of air or other gases relative to a planet's surface is referred to as wind. Changes in air pressure, which are mostly caused by temperature differences, create wind. When there is a difference in atmospheric pressure, air travels from the higher to the lower pressure area, resulting in varying speeds of wind. This article will explain to you about Types of Winds that will be helpful in preparing for Geography for the UPSC Civil service exam.

Wind

• The wind is the movement of air caused by differences in air pressure in our atmosphere.
• High-pressure air flows toward low-pressure areas.
• The greater the pressure difference, the faster the air flows.
• Winds also cause heat exchange between the various columns of air across the latitudes.
• Winds help to balance the world's unequal pressure distribution.

direction of Wind The direction of the Wind Rather than blowing north-south, the wind patterns generally blow east-west. This is due to the Coriolis effect, which is caused by the Earth's rotation. Wind systems twist counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere due to the Coriolis phenomenon. Coriolis Force Coriolis Force The Coriolis force is a force that is generated as the earth spins around its axis. In the northern hemisphere, this deflects the wind to the right, while in the southern hemisphere, it deflects the wind to the left. *To read more about this topic, click this link Coriolis Force Direction of Wind Measuring Instruments Measuring Instruments The anemometer is a device that measures wind speed. It's usually seen on top of a weather station or in an elevated position, and it's made up of 3-4 half-cups on arms spinning around a central axis. A wind vane (also known as a weather vane) is a device that is used to determine the direction of the wind. It's a flat object that rotates freely on an axis. It's usually in the shape of an arrow or a cockerel, although it can also be found on top of a weather station or other high-altitude items. Roof chimneys, church towers, and even communication towers are frequent places to find them. Anemometer

Types of Winds

Winds are generally divided into four categories:

1. Planetary winds
2. Periodic winds
3. Variable winds
4. Local winds

Planetary Winds

• The Planetary winds are the winds that always blow in the same direction throughout the year.
• They're also known as prevailing winds or persistent winds.
• These winds include Trade winds, Westerlies, and Polar Easterlies.

Planetary Winds

1. Trade Winds

   Trade Winds

• The trade winds are the winds that blow from subtropical high-pressure areas to the equatorial low-pressure belt.
• As a result, they are restricted to a portion of the earth's surface between 30°N and 30°S.
• In the northern hemisphere, they flow as the north-eastern trades, while in the southern hemisphere, they flow as the south-eastern trades.
• The Coriolis force and Farrel's law are used to explain the deflection in their predicted north-south orientation.
• In their origin areas (subtropical high-pressure band), trade winds are descending and stable, but as they approach the equator, they grow humid and warmer after collecting up moisture along the route.
• At the equator, trade winds from two hemispheres meet, and due to convergence, they ascend, causing heavy rainfall.
• Eastern trade winds, which are connected with cool ocean currents, are drier and more stable than western trade winds.

2. Westerlies

• Winds moving from subtropical high-pressure belts to sub-polar low-pressure belts are known as the westerlies.
• In the northern hemisphere, they blow from the south-west to the north-east, while in the southern hemisphere, they blow from the north-west to the south-east.
• Because of the huge expanse of ocean, the westerlies in the southern hemisphere are stronger and more persistent, whereas those in the northern hemisphere are irregular due to uneven relief of vast landmasses.
• Between 40° and 65° South latitudes, the westerlies flourish. For sailors, these latitudes are known as the Roaring Forties, Furious Fifties, and Shrieking Sixties.
• The westerlies' poleward edge is relatively variable. Seasonal and short-term changes are common. Wet spells and weather unpredictability are caused by these winds.

3. Polar Easterlies

• Polar easterlies are dry, cold winds that blow from the north-east to the south-west in the Northern Hemisphere and from the south-east to the north-west in the Southern Hemisphere.
• They blow from the subpolar lows' polar high-pressure regions.

Periodic Winds

• Seasonal winds that shift direction on a regular basis are known as periodic winds.
• The differential heating of land and water causes these winds.
• Monsoons are wind patterns that shift direction as the seasons' change.
• The Indian subcontinent's tropical monsoon winds provide an excellent example.
• They are also called secondary winds.

Periodic Winds

Monsoons winds

• Monsoons Winds were once thought to be a large-scale combination of land and sea breezes. As a result, they were regarded as a massive convectional circulation.
• The monsoons are distinguished by a seasonal shift in wind direction.
• During the summer, an apparent northward shift of the sun, as well as an intense low pressure centre in the north-west of the Indian subcontinent, drag the southern hemisphere trade winds northwards.
• Under the influence of Coriolis force, these winds are diverted to the right when they cross the equator.
• These winds are now becoming south-west monsoons as they approach Asia's landmass. As they travel such a long distance across a large body of water, they are saturated with moisture by the time they reach India's south-western coast, resulting in significant rainfall.
• During the winter, these conditions are inverted, resulting in the formation of a high-pressure core to the north of the Indian subcontinent.
• This anticyclonic movement, which flows southwards towards the equator, produces divergent winds.
• The apparent southerly travel of the sun aids this movement. These are the north-east or winter monsoons, which cause some precipitation along India's east coast.
• The monsoon winds blow across India, Pakistan, Bangladesh, Myanmar (Burma), Sri Lanka, the Arabian Sea, Bay of Bengal, southern Asia, northern Australia, China, and the Indian Ocean.
• Outside of India, the winter monsoon is stronger than the summer monsoon in eastern Asiatic countries like China and Japan.

Variable Winds

• Variations in the prevailing winds are caused by disturbances and changes in the local weather. Variable winds are the name given to these winds.
• Normally, cyclones, anticyclones, and storms form as a result of variable winds.

1. Cyclones

• Cyclones are a type of low-pressure environment with rapid inward air circulation. In the Northern Hemisphere, air flows counterclockwise, while in the Southern Hemisphere, it circulates clockwise.
• Storms and poor weather are frequently associated with cyclones.
• The word Cyclone comes from the Greek word Cyclos, which means snake coils. Henry Paddington invented the term because tropical storms in the Bay of Bengal and the Arabian Sea resemble coiled sea serpents.

2. Anticyclones

• Anticyclones are the polar opposite of cyclones, with outward-spiralling air circulation around a high-pressure center.
• The winds of an anticyclone swirl clockwise in the Northern Hemisphere around a high-pressure area.
• Air enters from above and sinks to the ground in anticyclones. Fairweather is usually associated with high-pressure centres.

3. Storms

• A storm surge, also known as a storm flood, tidal surge, or storm tide, is a coastal flood or tsunami-like occurrence of rising water that is frequently connected with low-pressure weather systems like cyclones. It is defined as an increase in water level over the regular tidal level, excluding waves.
• High-speed wind pushing water towards the coast over a long fetch is the principal meteorological component contributing to a storm surge.
• The shallowness and orientation of the water body in the storm path, the timing of tides, and the atmospheric pressure drop caused by the storm are all elements that determine storm surge intensity.

Local Winds

• Local winds are winds that blow only in a certain location for a short period of time, and the effects of these local winds are felt only in that area.

Local Winds

• They are typically seasonal and have names that are unique to the area, such as....

1. Foehn (Alps-Europe)
2. Sirocco (North coast of Africa)
3. Chinook (Rockies-North America)
4. Loo (Thar Desert- India)
5. Mistral (Mediterranean sea in France)
6. Bora (Mediterranean sea in Italy)

Significance of Winds

• Wind is an important aspect in predicting current weather and future forecasts.
• The wind is in charge of moving moisture and temperature from one place to another.
• Many daily weather patterns are influenced by wind.
• The direction of flight operations at an airport is usually determined by the velocity of the surface wind, and airfield runways are no exception.

Conclusion

Wind is the primary cause of erosion in arid areas. The general wind circulation transports microscopic particles like dust thousands of kilometres downwind from their place of origin over vast oceans. The passage of ocean currents from west to east across the world's oceans is driven by westerly winds in the planet's mid-latitudes. Wind plays a crucial part in the spread of seeds, spores, pollen, and other immobile creatures by plants and other immobile species. Despite the fact that wind is not the primary means of seed dispersal in plants, it is responsible for a significant portion of the biomass of terrestrial plants.