The HydrosphereThe Hydrosphere

The HydrosphereThe Hydrosphere

• The hydrosphere is all of the Earth’s water – both fresh and salt. Water covers about 70% of the surface of the Earth.

• Of this water on Earth – most of it (97.5%) is found as salt water. That means that only 2.5% of the Earth’s water is fresh water – the stuff we need to drink.

• Of all the fresh water on Earth, 87.3% of it is contained in the polar ice caps and glaciers. Less than 1% of the Earth’s fresh water comes from lakes and surface sources.

The Water CycleThe Water Cycle

• Water has an effect on the weather in all of its forms – solid, liquid and gas.

• Water on Earth ends up in the atmosphere (as vapour) due to the heat energy of the sun. This can occur through…– Sublimation – Solid water into vapour.– Evaporation – Liquid water into vapour.– Transpiration – Water loss from plants.

The Water CycleThe Water Cycle

• We need to get the water in the atmosphere back to Earth to complete the cycle.

• The water in the atmosphere condenses and falls as precipitation from the clouds. Precipitation may be rain, snow, hail, etc.

• The water continues to alternate between the ground and the atmosphere.

The Water CycleThe Water Cycle

Clouds & FogClouds & Fog

How Do Clouds Form?How Do Clouds Form?

• Clouds are formed in three ways – all of which have warm air with a lot of moisture in it meeting up with a drop in temperature.

• There are three cloud types

– Convective Clouds

– Frontal Clouds

– Orographic Clouds

Types of CloudsTypes of Clouds

• Convective Clouds – Moisture-filled air goes over very warm ground and rises up into atmosphere. Clouds form as moisture cools and condenses.

• Frontal Clouds – A warm air front meets and collides with a cold air front. The warm air is pushed up over the cold air where it cools and condenses and forms clouds.

• Orographic Clouds – Warm air with moisture is pushed up a mountain by the wind. The warm air rises, cools, condenses and clouds form.

Convective CloudsConvective Clouds

Convective Cloud FormationConvective Cloud Formation

Frontal CloudsFrontal Clouds

Frontal Cloud FormationFrontal Cloud Formation

Orographic CloudsOrographic Clouds

Orographic CloudsOrographic Clouds

What the Fog?What the Fog?

• Fog is actually a cloud that forms near the ground. Moisture-filled air blows over very cold ground (night or snow-covered usually). The moisture cools, condenses and forms clouds just above the ground – fog!

FOG!FOG!

FIN