Water in the atmosphere Mr Boland Geography Water

Water in the atmosphere Mr Boland Geography

Water Vapour 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.

Three different types of cloud Cirrus clouds Cumulus clouds Stratus

Cirrus Clouds Cirrus clouds are wispy clouds very high in the sky and look like a painters brushstroke. They indicate fair weather.

Cumulus Clouds Look like cotton wool Found at middle altitudes Sometimes bring showers

Stratus Clouds 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.

Name these clouds 1 2. 3

Precipitation. 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!

Relief Rain How do the hills & mountains cause rain? ? Why is there no rain on the east of the Cascade Range? ? ?

Relief Rain 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

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

Convectional rainfall is common in very hot parts of the world.

Cyclonic Rain 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.