Atmosphere, weather and climate (Unit #7)

guy 2nd sem

Weather watch

severe weather is POSSIBLE

Weather warning

When severe weather is posing an immediate threat to life or property

Blizzard

Strong storm with strong winds, cold temps., low visibility lasts 3 or more hours

Thunder storms

heavy rain and wind thunder, lightning, and maybe hail

How do thunderstorms occur?

At cold fronts when where warm, moist air is forced rapidly upward.

what causes strong winds

Strong updrafts of warm air and sinking rain-cooled air

when does lightning happen?

when different parts of the cloud become oppositely charged. 

how is a tornado formed

Wind at different heights blow in different directions and speeds causing a rotating column of air.

Pressure it measured with

Barometer

what causes low pressure

hot air expanding and becoming less dense while rising

what causes high pressure

cold air sinking and becoming more dense

wind vane

measures wind direction

anemometer

measures wind speed

what causes heat

the sun heating up air molecules causing them to move quickly

thermometer

measures temp.

True or false. Can warm air hold more water vapor?

True

Relative Humidity

is the amount of water vapor actually in the air, compared to how much it CAN hold at a specific temperature.  It is measured in percent.

• psychrometer or hygrometer. 

measures humidity

Dew point

• the temperature at which the air is saturated and leftover water condenses. 

how do clouds form

when water vapor condenses into tiny water droplets. The air has to be at the dew point and there has to be condensation nuclei (dust) for the water to stick to. 

stratus clouds

• smooth, even layers usually at low altitudes

Cumulus clouds

• puffy, white clouds, often have flat bottoms

Cirrus clouds

• hin, feathery clouds made of ice crystals

Nimbus clouds

like cumulus but taller and dark and full of water. Sunlight cannot pass through

Cirro clouds

high clouds

alto

• middle-elevation clouds

strato

low clouds

what determines the type of precipitation?

Air temperature

what is earth's atmosphere?

a thin layer of gases that protects the Earth’s surface from the Sun’s harmful UV rays, it contains oxygen we need to breath, and it balances the heat received and released on Earth.

what was the earths early atmosphere made of?

• mostly hydrogen and helium and very little oxygen.

later what did volcanoes add to the atmosphere

• carbon dioxide, carbon monoxide, and water vapor.

what made it possible for animals to live (life)

photosynthetic life (cyanobacteria) which converted carbon dioxide into oxygen

what solids help make up the atmosphere?

dust, salt, and pollen

what are some liquids that help make up the atmosphere?

water droplets

what gases help make up our atmosphere?

nitrogen (78%), oxygen (21%), carbon dioxide, water vapor, and other trace gases.

another word for car exhaust

smog

CFC

destroy ozone layer

Troposphere

Lowest Layer sea level up to 10km. It contains most of the water vapor and gases. 

• Warmed by the Earth’s surface so temperature decreases with altitude.

• Contains the Jet Stream

JET STREAM

narrow belt of strong winds at the top of the troposphere responsible for developing storms AND moving them across the country.

STRATOSPHERE 

2nd layer 10 km to 50 km. Contains the highest amount of ozone. 

• Temperature increases with altitude because ozone absorbs a lot of heat. 

ozone

9km to 48km – absorbs ultraviolet radiation from the sun. 

MESOSPHERE

3rd layer 50 km to 85 km. Meso means middle.

• shooting stars occur here.

Temperature decreases with altitude.

THERMOSPHERE

4th layer 85km to 500km. hickest part of the atmosphere

• very very hot!

• Temperatures increase with altitude.

Ionosphere

• ayer of charged particles within the mesosphere and thermosphere that help carry radio waves.

EXOSPHERE

Above 500 km.. Outermost layer

• International space station orbits in this layer.

• Very Hot

About 30% of the Sun’s energy is…..

reflected

The remaining 70% is……

• absorbed by oceans, land, and the atmosphere.

ex of radiation

Sun’s radiation warms a sandy beach, but radiation also transfers energy from the sand to the air.

ex conduction

• Earth’s surface to air, and air to air.

ex convection

Warm air rises.  Cold air sinks

Mars is lifeless and cold because

• its atmosphere of mostly carbon dioxide is too thin.

Venus is lifeless and hot because

• its atmosphere of mostly carbon dioxide is too thick.

WIND is caused by

• pressure differences and   air moves from high pressure to low pressure. 

what causes global wind patterns

uneven heating of the earth

Warm air at the equator

rises and moves toward the poles.

Cold air from the poles

• sinks and moves towards the equator. 

Because of the Earth’s rotation, all of it is curved by the

coriolis effect

what two things effect the worlds wind patterns

Global Wind patterns and the Coriolis Effect

Near the equator, everything is hot, not a lot of temperature differences, so……

there isn’t a lot of wind.

what do we call the area near the equator where there isn’t a lot of wind ?

the doldrums

Trade winds

• Air near the equator warms, rises and moves towards the poles.  At about 30⁰ latitude, it gradually cools, sinks, and returns back to the equator along Earth’s surface.

Prevailing Westerlies

• Movement of air is west to east. 

• This global wind is responsible for giving the USA their weather.

Polar Easterlies

• Cold dense air from the poles sinks and moves away from the poles. 

• Wind moves from east to west in this zone.

SEA BREEZE

• During the day the land heats up and the air above the land rises and allows the cool air from the sea to come in. 

LAND BREEZE

• At night the land cools off and air above the land sinks and allows the warm air from the sea to come in.

Air mass

•  a large body of air with temperature, and moisture properties just like where it formed. 

 FRONT

• the boundary between two air masses. 

where do the differences in temperature and moisture of two air masses occur at?

frontal boundaries

Cold Front

• colder air replaces warmer air by advancing UNDER warm air.

why do cold fronts produce thunderstorms/heavy rain?

because of quickly rising warm air

Warm Front

• warmer air advances OVER colder air.

what weather is associated with warm fronts

light rain fall (steady)

Stationary front

• when a the boundary between two air masses

 stop moving.

May last for days.

what weather is associated with stationary fronts?

light wind and rain

Occluded Front

• Occurs when cold air moves towards a cool air mass, and forces warm air upward.

Isotherms

lines on weather maps connecting points of equal temperature.

Isobars

connect points of equal pressure.

climate includes..(2)

temperature and precipitation.

5 major things affecting climate

• latitude, elevation, proximity to water, position relative to mountains and proximity to cities. 

how does latitude effect climate?

affects the amount of sunlight certain areas on earth get(temp.)

lower altitudes get….

more heat

higher altitudes get……

less heat

how does elevation affect climate? (mtns)

• because low elevations are usually warm and high elevations are usually cold. 

how does proximity to water effect climate?

• These areas generally experience warmer winters and cooler summers than other areas at the same latitude. (water changes temp. slower than land)

how do mountains affect climate?

• Clouds full of rain drop their water on top of the mountain, making it rainy or snowy.

• By the time the cloud gets over the mountain it has dropped most of its rain, so areas on the other side of the mountain are often much drier and are said to be in the rain shadow. 

how do cities affect climate?

• Because cities have lots of concrete, pavement, light, people, they absorb a lot of heat. 

• Cities frequently have higher temperature than surrounding areas and can alter climate patterns. 

where are tropical climates found?

near the equator get lots of direct sunlight and have high temperatures year round. 

temperate climates

• have some direct sunlight, experience seasons, and have moderate temperatures. 

Polar climates

• get very little direct sunlight so they have low temperatures overall. 

El Nino

• is when normally strong Pacific winds weaken or reverse. 

what does el nino alter?

• the jet stream which changes wind and precipitation patterns around the world. 

La Nina

•  when strong Pacific winds are stronger than normal. 

how can we tell earths climate has changed?

• We can tell this by looking at the fossil record and by looking at gas composition in ice cores at the poles.