Table of Contents Chapter: Atmosphere Section 3: Air Movement
We will learn about Air Movement=Wind -Why different latitudes on Earth will receive different amounts of Solar Energy -The Coriolis Effect -How water and land affect the air above them
Why it s important: Wind systems will affect weather and climate all over the Earth
We know: When substances are mixed: less dense will float on the denser one **different densities cause convection currents **This is also valid for the air in the atmosphere and water in the hydrosphere
Air Density What happens to the molecules of a substance when this substance is warmed up? Does the density change? The molecules or particles will expand and the substance will become less dense
Density of gases depends on temperature Higher temperature - lower density: air rises Lower temperature higher density: air sinks
*The density of the air affects Air Pressure Air Pressure force exerted by the molecules of air present in the atmosphere Read page 103 and write down on your notebook how air density can affect air pressure
*The density of the air affects Air Pressure In areas where the air is heated (less dense), the air pressure is lower, because the molecules are further apart from each other. In areas where the air is cold, the air pressure is higher.
Air Movement Wind What is wind? Wind is the movement of air from an area of higher pressure to an area of lower pressure
**Air Movement Wind Earth surface has land and water Land and water - strongly influence global wind systems Land and water absorb heat differently, creating areas with different air pressure, generating wind Land and water absorb heat differently because of their specific heat
Heated Air Areas of Earth receive different amounts of radiation from the Sun because Earth is curved. some areas are warmer than others. areas closer to the Equator are warmer
Longitude and Latitude latitudes closer to the Sun receive more radiation and are warmer
How are Winds formed? 1)The heated air at the equator is less dense. 2)Moves up in the atmosphere 3) It is replaced by denser, colder air from the poles, creating convection currents
*Forming Wind The differences in air temperature and density, generate areas with different air pressures in the atmosphere, which creates all the winds that circulate around the globe.
How air moves
What causes wind? 1) As we have seen: the difference in temperature and density of the air in different areas, but also. 2) the Coriolis Effect phenomenon that also causes winds
*Coriolis Effect *Coriolis Effect Coriolis Effect happens due to the rotation of the Earth. It appears that winds and water are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
*Coriolis Effect *It is a phenomenon that causes fluids such as air and water to curve as they travel across and above the Earth s surface, affecting how winds and storms move around Earth and therefore the climate and weather.
Coriolis Effect: Fun Fact
Specific Heat of Water Specific heat of the water will affect the movement of air. read page 659 and copy the definition of specific heat. Read page 659 and explain how the specific heat of water differs from the specific heat of many other substances
Local Winds: Sea and Land Breezes These breezes will blow in one direction during the day and to the opposite direction at night.
Sea and Land Breezes *This constant air movement happens because of the differences in the temperatures and density of the air above land and water.
Sea and Land Breezes It takes more time for the water to cool down and warm up compared to the land (Sp. Heat), this affects the temperature and density of the air above it and the local wind patterns. Water has a high specific heat when compared to other substances
- Sea breeze the cool air - Land breeze the cool air
Global Winds affect the weather patterns of the entire planet Local Winds affect local weather Sea breeze and Land breeze