Atmospheric Pressure and Winds

Flashcards on atmospheric pressure, factors affecting it, global pressure belts, and winds.

Atmospheric Pressure is recorded in?

Usually recorded in units like millibar (mb) or Hectopascal (hPa).

What are the factors affecting atmospheric pressure?

Temperature, altitude, and humidity.

What is the relationship between temperature and atmospheric pressure?

Temperature and atmospheric pressure are inversely proportional.

How does temperature affect air pressure?

Air expands, gets heated, and rises up, thus forming low-pressure regions.

How are high-pressure regions formed?

Rising air gradually cools, contracts, and subsides to form high-pressure regions.

What is the relationship between altitude and atmospheric pressure?

Altitude and atmospheric pressure are inversely proportional.

What is the rate of vertical variation in atmospheric pressure?

The vertical variation of atmospheric pressure occurs at a rate of about 1 mb per 10 meters.

What is the relationship between humidity and atmospheric pressure?

Humidity and atmospheric pressure are inversely proportional.

How does humidity affect atmospheric pressure?

As humidity increases, water molecules displace heavier gases, causing atmospheric pressure to become low.

What are isobars?

Imaginary lines connecting places having equal atmospheric pressure.

Name the global pressure belts.

Equatorial low-pressure belt, subtropical high-pressure belt, subpolar low-pressure belt, polar high-pressure belt.

What is equatorial low pressure belt?

.The expansion and rising up of air due to high pressure prevailing in the equatorial region is the cause for the formation of equatorial low pressure belt

. This zone of vertical air current is devoid of wind. Being the wind less zone this pressure is also called doldrum

What causes the equatorial low-pressure belt?

Caused by the expansion and rising up of air in the equatorial region.

What is the windless zone?

Also called doldrums; a zone devoid of winds.

How are polar high-pressure belts formed?

Formed as a result of the contraction and subsidence of cold air.

How is the subtropical high-pressure belt formed?

Rising warm air along the equator moves poleward, cools, and subsides at about 30° N/S latitude.

How are subpolar low-pressure belts formed?

Caused by the continuous throwing up of air along these regions due to the rotation of the earth.

What are air currents?

The vertical movements of air.

What are winds?

The horizontal movement of air from high-pressure areas to low-pressure areas.

What are the factors influencing the speed and direction of wind?

Coriolis force, pressure gradient force, and frictional force.

How does the Coriolis force affect wind direction?

The wind deflects towards the right in the Northern Hemisphere and towards the left in the Southern Hemisphere.

What is pressure gradient?

The change in pressure over a horizontal distance.

How does pressure gradient affect wind speed?

If the pressure gradient is high, the speed of the wind will be high, and vice versa.

How does friction affect wind speed over the ocean and plains?

The speed of the wind will be high over the ocean surface and plains as the friction is less.

How does friction affect wind speed over hills, mountains, forests, and structures?

The speed of the wind will be less over hills, mountains, forests, and structures as the friction is high.

What is an anemometer?

An instrument used to measure the speed of winds.

What is a wind vane?

An instrument which indicates the direction of the wind.

Name the different types of winds.

Permanent winds, periodic winds, local winds, and variable winds.