Water in the Atmosphere+

Weather

Chapter 23+24

Latent heat –

• Evaporation (__ ___)& Condensation (__ ___)• Sublimation –

• Deposition

NO LIQUID PHASE!

Humidity –

Controlled by rates of __________________ and __________________– Saturated air: condensation = evaporation – If condensation rate is greater than evaporation

rate, rain droplets form– Part of total atmospheric pressure

Dew Point –

• Absolute Humidity

• Relative Humidity –

Clouds • Clouds are comprised of liquid droplets of various sizes

and/or ice crystals • __________ ___________allow water vapor to

condense on it to form raindrops

Expansional Cooling & Compressional Warming

Adiabatic cooling –

Adiabatic Lapse Rate – how fast a parcel of air warms up or cools down because of rising or sinking

Advective Cooling-

CA Marine layer: warm air over ocean flows inland, ground is cold and causes condensation

Clouds are characterized according to their height and vertical development:

• High Clouds: – cirrus (Ci) – cirrostratus (Cs) – cirrocumulus (Cc

• Middle Clouds – Altostratus (As) – Altocumulus (Ac)

• Low Clouds: – Stratus (St) – Stratocumulus (Sc) – Nimbostratus (Ns)

• Clouds with vertical development: – Cumulus (Cu) – Cumulonimbus (Cb)

Precipitation-

• Rain gauge – collect rain in cylinder, measure in inches

• Snow – measured using a yardstick

• Coalescence –

• Supercooling – substance cooled below

freezing, condensation or sublimation point without phase changes

• Cloud seeding –

Natural Science Warm Up1/29/14

Write the question, please!

1. Fair weather cloud- _____________2. Lowest level cloud, may cause light drizzle or fog-

_______________3. Fluffy and cotton-like cloud, most likely to cause

precipitation- ____________

Precipitation1. The sun heats up water on the surface of the earth, turning it into vapor.2. Water vapor is less dense, which causes it to rise.3. The vapor cools when it reaches the dew point and condenses back into

liquid in the form of clouds.4. The water droplets in the clouds coalesce until they are too heavy for the

atmosphere to hold them and the droplets fall as precipitation.

Hail normally occurs in thunderstorms and is the result of strong updrafts that repeatedly carry growing chunks of ice upwards into the clouds. Once the hail stones become too heavy to be lifted by the updrafts, they fall to the ground.