Moisture in the Atmosphere

What makes a Cloud?

1. Moisture

2. Reduction in pressure or temperature causing condensation.

3. Condensation nuclei - small particles in the atmosphere around which cloud droplets can form. Dust

SaltSmoke

Cloud Formation• Orographic lifting occurs when wind encounters a

mountain and the air has no place to go but up.

• The air expands and cools resulting in cloud formation.

Orographic lifting occurring in Maui.

Cloud Formation• Cloud formation occurs with the collision of air masses

(fronts) of different temperatures.

• As fronts collide clouds form

Weather Map

– Warm air rises quickly and forms cumulonimbus clouds and thunderstorms (Sometimes tornados)

Stability

– How rapidly any given mass of air cools determines its stability.

– Stability is the ability of an air mass to resist rising.

–Latent heat is stored energy in water vapor that is not released to warm the atmosphere until condensation takes place.

How to Classify Clouds based on Height

• Cirro – 6000 m or higher

• Alto – 2000m to 6000m

• Strato – below 2000m

How to Classify Clouds based on Shape

• Cirrus – Thin and Wispy » Latin – hair

• Cumulus – Puffy-flat bottom» Latin – pile or heap

• Stratus – Sheet like » Latin – layer

• Nimbus - Rain» Latin - Cloud

• The constant movement of water between the atmosphere and Earth’s surface.

– Evaporation – liquid to gas– Condensation – formation of water droplettes– Precipitation- Rain – (Evapo)transpiration- plants loose water

through stomata

Water Cycle

The Water Cycle