Download Water in the atmpsphere

Mr Boland
Geography
Water vapour is moisture in the form
of gas in the air
 Relative humidity is the percentage of
water vapour in the air.
 Warm air holds more water vapour
than cool air.
 Condensation happens when the air
becomes saturated and the tiny water
droplets become clouds.

 Cirrus
clouds
 Cumulus clouds
 Stratus


Cirrus clouds are wispy
clouds very high in the
sky and look like a
painters brushstroke.
They indicate fair
weather.



Look like cotton wool.
Found at middle
altitudes
Sometimes bring
showers


Stratus clouds are low
thick layers of dark
clouds that cover an
area like a blanket.
These clouds can bring
long spell of rain and
drizzle.
1
2.
3


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Precipitation happens when air is forced to
rise cooling the water vapour into tiny
droplets.
Precipitation is all types of water that falls
from the sky such as rain, snow, sleet, hail
stones.
Rain is the most common.
The three main types of rain are
1. Relief
2. Convectional Rain
3. Cyclonic Rain
Types of Rain
Hot air rises!
How do the hills & mountains cause rain??
Why is there no rain on the east of the
Cascade Range???




Moist air is forced to rise over mountains.
As air travels up the windward side it gets
colder and forms clouds and rains.
Clouds lose most of there rain before it go
over the mountain so there is less rain on the
leeward side of the mountain
This is called the rain shadow
Relief Rain
Relief rain


What are at the areas
of dark blue?
Why does the area
around Dublin have the
least amount of
rainfall.
Relief Rain in Ireland
Describe what is happening in this diagram??
Where about in the world do we get this rainfall??
Convectional Rain
 Occurs
when warm air rises very
quickly. This is common during a
warm Irish summer or on the equator.
1. The sun heats the earth.
2. The hot air over the land rises
quickly.
3. As the air rises it cools.
4. It forms cumulus clouds and there
are heavy showers.
 This
rain is associated with
low pressure systems like a
depression.
 It forms as warm and cold air
masses meet.
 Warm moist air rises cools and
rains.
Frontal rain