Air Pressure and Wind

High Pressure System

A mass of cool, dry air that typically brings good weather with light winds

Low Pressure System

A mass of warm, moist air that typically brings stormy weather with strong winds

Barometer

A scientific instrument used to measure air pressure.

Low pressure system

Warmer temperatures, moist, tend to be less stormy

How do changes in temperature and humidity affect air pressure?

When it is hot, the air goes up and the pressure is low. When it is cold, the air goes down and the pressure is high. When the air is dry, the air goes up and the pressure is low. When the air is humid, the air goes down and the pressure is high.

How can isobars on a weather map be used to identify high and low pressure systems?

When the numbers on the isobar are lower, it is a low pressure system. when the numbers on an isobar are higher, then it is a high pressure system

Temperature- Pressure System- Local wind

When the temperature is hotter, there is low air pressure thats rises and expands, low density, and high humidity levels. When the temperauture is colder, there is high air pressure that sinks and compreses, more density, and low humiity levels. Wind blows from high air pressure to low. During the day, the land is warmer than the ocean so the ocean would have a higher air pressure. This creates a sea breeze. During the night, the ocean still is heating because of its convection movements which causes it to have a low air pressure. Then, the breeze would be coming from the land, so it would be called a land breeze.

What are the main elements in the atmosphere?

78% nitrogen gas, 21% oxygen, and 1% contains other small particles (dust, volcanic ash, sea salt, dirt, smoke)

Isobar

A line on a map that connects points containing the same atmospheric pressure at a certain time

Anticyclones

Areas that have high pressure. Cooler, denser air moves out of center of high pressure areas toward areas of lower pressure. Cooler temperatures, low humidity, cP, clockwise flow, winds curve to the right, more dense.

Cyclones

Areas that have lower pressure than surrounding areas do. The rising air causes stormy weather. Wamer temperatures, counterclockwise flow, high humidity, winds curve to the left, mT, less dense.

Pressure Belts

Bands of high and low pressure found every 30 degrees latitude

High pressure system

Cold temperatures, dry, tend to be more stormy

Global Winds

Combination of convection cells found at every 30 degrees of latitude and Coriolis effect produces patterns of air circulation

How does the Earth's rotation affect wind patterns in the northern and southern hemispheres?

For the northern hemisphere, the wind blows counter clockwise starting with high pressure ending with low pressure. For the southern hemisphere, the wind blows clockwise and starts at high pressure, ending at low.

Cold

High air pressure, more dense, sink, contract

Pressure Gradient

How close the isobars are to each other; the closer the isobars the higher the pressure gradient

Hot

Low air pressure, less dense, rise, expand

Atmosphere

Mixture of gases that surrounds Earth

Wind

Movement of air caused by differences in air pressure

Coriolis Effect

The apparent curving of the path of winds and ocean currents due to earth's rotation

Local Winds

Small convection winds of a local area caused by temperature differences. If the terrain is more rough, the winds will be greater influenced

Air Pressure

The measure of force in which air molecules push on a surface

What is the main cause for global wind patterns?

The rotation of earth and coriolis effect