Welcome!

Jr. Meteorologist!

Why do we need to study weather?

How would you like to attend an outdoor picnic in

the rain?

Do you like to know when a severe storm is coming?

We get this information from television, radio,

newspapers, and weather radios.

We receive this information from trained individuals

called meteorologists.

A meteorologists is a scientist who studies the

atmosphere and its changes in order to predict daily

weather.

Weather and Climate

What is the weather like today?

Is it like this EVERY day? Why?

Or why not?

Prediction: What is the difference between

WEATHER and CLIMATE?

The Layers of the Atmosphere The layers of the atmosphere are

defined by changes in temperature.

For example, -sphere means “ball,”

which suggests that each layer of

the atmosphere surrounds the Earth

like a hollow ball. Tropo- means

“turning” or “change,” and the

troposphere is the layer where

gases turn and mix. Strato- means

“layer,” and the stratosphere is the

sphere where gases are layered

and do not mix very much. Meso-

means “middle,” and the

mesosphere is the middle layer.

Finally, thermo- means “heat,” and

the thermosphere is the sphere

where temperatures are highest.

Layer by Layer

The troposphere is

the first layer above

the surface and

contains half of the

Earth's atmosphere.

Weather occurs in

this layer.

The Atmosphere

BIG IDEA: Earth’s

atmosphere is a mixture

of gases that distributes

heat and enables life to

exist on Earth.

What makes up DRY air in the

atmosphere?

– 78% nitrogen--used to make protein

– 21% oxygen (from photosynthesis)—

processes that use oxygen:

cellular respiration (plants and animals)

oxidation (like rust, tarnish)

combustion*

--1% other gases (argon,

carbon dioxide, other)

What makes up air (atmosphere)?

Weather

Weather is constantly

changing, and it refers to

the state of the

atmosphere at a given

time and place

In other words…

In other words…what it’s

like OUTSIDE, right

HERE, right NOW

Measureable

properties of weather

air temperature

humidity

type and amount of

precipitation

air pressure

speed and direction of wind

Climate – The long-term

environmental conditions across

a large area and long time.

Climate, however, is based on the

average, year-after-year

conditions of temperature,

precipitation, winds, and clouds in

an area.

Climate helps describe

a place or region

Reading Check:

What is the

difference between

WEATHER and

CLIMATE?

What affects weather and climate?

There are two major factors that affect the

overall environment and climate…

-The tilt of the Earth in relation to it’s

orbit around the Sun

- The direction of that tilt that

changes as the Earth travels around

the Sun

First, some basic vocabulary…

Revolution – one ORBIT, or trip around the

Sun. This takes the Earth 365 ¼ days

Rotation – one

SPIN of the

Earth on it’s

axis. This

takes about 24

hours…one

DAY.

Earth’s TILT

The Earth is not vertical (straight up-and-

down) in relation to it’s orbital path, it’s tilted

23 ½ degrees from vertical.

This tilt means

that the Sun’s

energy doesn’t hit

the Earth equally.

Earth’s TILT

This tilt results in uneven heating of the

Earth’s surface.

“Direct”

sunlight

“Indirect”

sunlight

Distributing the Sun’s Heat - WIND

RULE #2 OF NATURE – Nature seeks

balance (equilibrium)

Create Wind is the

movement

of air from High

pressure to Lowpressure

HOT

air

RISES

COLD

air

SINKS

Precipitation – Nature’s Thermostat There are 3 basic causes for rain. They are:

– Convection – due to evaporation and cooling

Sun’s energy causes surface water to evaporate and become humidity

As the day cools off, the air cools and condenses, causing storms and rain

Usually in tropical environments

Precipitation

–Frontal – due to changes in temperature

Starts with warm, moist air at the surface and above

As a cold front approaches, it stays low, forcing the moist air aloft

This cools and condenses the air, creating rain on the “leading edge” of the front

Usually in mid-latitudes where warm and cold air systems collide

Precipitation cont. Orographic – due to changes in elevation

– Moist air travels over land and approaches a steep rise in

elevation

– As the air is forced up the side of the rise, the air cools,

causing precip. on the “windward” side of the

mountain

– As the (now dry) air continues over and down the

“leeward” side of the mountain, it warms up and

absorbs any available

moisture, creating a “rain

shadow desert”

– Found in areas of

mountains or other

rapid elevation change

Latitude

Due to the Earth’s tilt, the amount of sun

energy changes over the earth’s surface…

Tropical (Low Latitude) zone –

year-round direct sunlight, always

hot

Temperate (Mid-Latitude) zone

– seasonal, most varied climates

Polar (High Latitude) zone –

either mild temps. or extreme cold

RULE: The HIGHER the latitude,

the COLDER the temps.

Altitude (Elevation) Higher elevation = thinner less

air, therefore less air to hold heat

makes it colder.

RULE –

The HIGHER

the elevation,

the COLDER the

temperatures.

Nearness to Water Land heats up and cools down QUICKLY.

Water heats up and cools down SLOWLY.

Therefore, water acts like a blanket… holdingheat and releasing it slowly.

This results in smaller daily and seasonal temperature changes near large bodies of water.

“Coastal” areas are humid, “continental” areas are dry

30 degree change

in Houston45 degree change

in Denver

Direction of Currents Global wind and ocean currents transfer heat

and moisture around the world, and help carry

moisture from the oceans to the land

– Warm water moving toward the land brings moisture (H2O)

– Warm water moving parallel to the coast brings heat, no H2O

– Cool water brings cool, dry air -> mild or desert climates

Reading check

How do humans

impact the

atmosphere and how

does this affect our

lives?

Climate Zones Climate zones are divided into regions: The

three climate zones of the world are the tropical

zone, the temperate zone, and the polar zone.

There are two key characteristics differences:

– Amount of moisture (rain), and

– Typical temperature range through the year

These two characteristics are affected by

balancing the effects of four factors:

Latitude

Altitude

Nearness to water

Direction of atmosphere and ocean currents

How it Works...

Tropical Wet Climate

Latitude – in the

tropics HOT

Altitude – low land

doesn’t stop air flow

until mtns. in the west

Nearness – flat land

“acts coastal”, allows

moisture inland

Direction – air flow

brings in warm, moist air

from the ocean which then hits the mountain and rains

The Tropical ZoneFigure 1 Biomes of the Tropical Zone

Temperate and Polar Zones

Temperate and Polar Zones

Reading check

Why are there

different climates on

the earth? Explain

with details.

Student led closingThe arrows in the cross section below show winds moving across

northern New York State into Vermont during the summer.

Compared to the climate of location A, the climate of location B is… Why?

a. warmer and wetter c. cooler and drier

b. cooler and wetter d. warmer and drier

The map shows an imaginary continent on Earth. Arrows represent wind

direction. Letters A through D represent locations on the continent.

Locations A and B are at the same latitude and at the same elevation at

the base of the mountains.

The climate at location C is much drier than at location D. This difference is

best explained by the fact that location C is located….

a. at a latitude that experiences longer average annual daylight

b. at a latitude where air is sinking and surface winds diverge

c. farther from any mountain range

d. closer to a large body of water

Done?