Our Changeable Weather
ALL will know some reasons as to why our weather is
so changeable.
MOST will be able to describe the different air masses
that affect our weather.
SOME will successfully complete a GCSE question on
air masses!
Our Changeable Weather
Our weather can change really fast in the UK.
Warm and sunny one day. Cool, wet and windy
the next. Why? Because blocks of air are on the
move!
Air On The Move
• Some parts of the earth are hot and some are cold. This
causes air to move around – like the air in a cold room
when you turn on a heater.
Warm air moves
from a warmer
place to a colder
one.
This means the
cold air is pushed
towards the
warmer place.
What is an air mass?
• Watch this video from the Met Office.
• An air mass is...
• http://www.youtube.com/watch?v=kvkhBFnBTI
Air Mass = A large body
of air that has properties
similar to the part of the
Earth’s surface over
which it develops.
If an air mass travels over the sea it will be wet.
If an air mass travels over land it will be mostly
dry.
If an air mass travels from the North it will
likely be cold.
If an air mass travels from the south it will be
likely be warm.
An air mass
will be
warm or
cold, wet or
dry
depending
on where it
has come
from.
BBC Class Clips
• http://www.bbc.co.uk/programmes/p00xq8t8
Air Mass
Tropical
Maritime
Polar
Maritime
Arctic
Maritime
Polar
Continental
Tropical
Continental
Origin
Atlantic
Greenland/
Canada/ North
Atlantic
The
Arctic
Central
Europe /
Scandinavia
Northern
Africa
Weather
Why?
Warm, moist air
Rain and drizzle are due to the
brings cloud, rain and air mass moving over the
mild weather
Atlantic. Warm and mild as it
has originated near the tropics.
Wet, cold air brings
showery weather.
Wet, cold air brings
snow in winter
Hot air brings dry
summers. Cold air
brings snow in winter.
Hot, dry air brings
hot weather in
summer.
Wet as it has travelled
over the ocean, cold as it
is originating close to
North Pole
Wet as it has travelled
over the Arctic ocean,
snow due to the fact the
Arctic is extremely cold.
Dry summers/snowy winters
due to conditions in Central
Europe at these times –
little time over sea.
Hot as it has originated in
the Tropics, dry due to
mostly travelling over land.
GCSE Geography Question
GCSE Geography Question
• Good habits
• 1. Circle the command word(s)
• 2. Underline key words
Plenary
• BBC Bitesize