Which is the odd one out? PrecipitationRelief rainfallMountain Water vapourRiverAir rising Air...

Which is the odd one out?

Precipitation Relief rainfall Mountain

Water vapour River Air rising

Air pressure Barometer Rain gauge

Cumulus Convectional rainfall

Stratus

Wind vane Thermometer Condensation

© Teachable . Some rights reserved. http://teachable.net/res.asp?r=4394

Learning objectives – How does air pressure affect the weather?


Title

Air Pressure and the Weather. Anticyclones


What is air pressure?

• Although we can’t feel it, all the air above us is pressing down on us, giving air pressure. If air pressure is low, it means air is rising. If it is high it means air is sinking. Each brings different weather.

barometer


•B•A

Higher pressure

windFalling pressure

Low Pressure Weather - look at what happens when warm air rises

1. Warm air is rising here, around A So the air pressure falls at A

Air pressure is higher. So air rushes from B to A as wind

So a fall in air pressure is a sign of rain and wind. The lower the pressure the worse the weather will be. This is called a depression.


•Y•X

High Pressure Weather – when warm air rises in one place, cool air sinks somewhere else

1. Warm air is rising here, around X

2. So cold air gets pushed aside…

4. Now Y has high pressure

3… and far away at Y it sinks, this causes the air pressure at Y to rise

5. As the cold air sinks it warms up. So no water vapour condenses and no clouds form over Y. The sky stays clear. This is called an anticyclone.© Teachable . Some rights reserved. http://teachable.net/res.asp?r=4394

So high pressure means….

• No clouds, which means it gives us our hottest summer weather and coldest winter weather. Anticyclones.

Low air pressure means•A fall in air pressure is a sign of rain and wind. The lower the pressure the worse the weather will be. Depressions.


Which is the correct word from each pair?

1. Low pressure is a sign of fine/unsettled weather.

2. The lower the pressure the calmer/stormier the weather will be.

3. High pressure brings clear/cloudy skies, which means very hot/cold weather in summer and very warm/cold weather in winter.


When there is high pressure in _______…

There are no clouds in the way so the sun is strong. Take care you don’t get burnt!

Since there is no cloud to trap the heat in, the evenings can be cool.

No cloud means no rain, so there may be drought in some places

No cloud also means the ground gets cold at night. Water vapour condenses on grass to form dew


When there is highpressure in ______

There is no cloud to act as a blanket. So the days are clear, cold and bright

With no cloud, the ground cools fast at night and cools the air above it. Water vapour condenses and freezes on cold surfaces, giving frost

Water on roads freezes into ice as the sun goes down

Ice and frost means animals have trouble finding food

Water vapour condenses on dust and other particles in the air, giving fog. This makes driving dangerous


Which is the odd one out? PrecipitationRelief rainfallMountain Water vapourRiverAir rising Air...

Documents

Transcript of Which is the odd one out? PrecipitationRelief rainfallMountain Water vapourRiverAir rising Air...