Earth-Sun RelationshipEarth-Sun Relationship

(Use with Notes and Homework Quiz (Use with Notes and Homework Quiz handout)handout)

Weather vs ClimateWeather vs Climate

What is the weather like today?What is the weather like today?

Is it like this EVERY day? Why?

What is the difference between WEATHER and CLIMATE?

Weather and ClimateWeather and Climate Weather Weather – The – The temporary temporary environmental environmental

conditions in a localized area over a short conditions in a localized area over a short period of time.period of time.

*In other words…what it’s like OUTSIDE, right HERE, right NOW

ClimateClimate – – The long-term The long-term environmental environmental conditions across a large area and long time.conditions across a large area and long time.

*In other words…the AVERAGE of all the WEATHERS

What affects weather and climate?What affects weather and climate?

There There are two major factors that affect the are two major factors that affect the overall environment and overall environment and climateclimate……

-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…First, some basic vocabulary…

RevolutionRevolution – – one ORBITone ORBIT, or trip around the , or trip around the Sun. This takes the Earth Sun. This takes the Earth 365 ¼ days365 ¼ days

Rotation – one SPIN of the Earth on it’s axis. This takes about 24 hours…one DAY.

EarthEarth’’s s TILTTILT The Earth is not vertical (straight up-and-down) in relation to itThe Earth is not vertical (straight up-and-down) in relation to it ’’s s

orbital path, itorbital path, it’’s s tiltedtilted 23 ½ degrees from vertical23 ½ degrees from vertical..

This tilt means that the Sun’s energy doesn’t hit the Earth equally.

EarthEarth’’s s TILTTILT

This This tilt results in uneven heating of the tilt results in uneven heating of the EarthEarth’’s surfaces surface..

“Direct” sunlight

“Indirect” sunlight

Section 1Section 1

The relationship between the Earth and the sun affects climate, which influences life on Earth in dramatic ways.

Climate and Weather

• Earth’s tilt is one reason for variations in sunlight.

• The angle of tilt affects the temperature, which is measured in Fahrenheit or Celsius.

• Earth rotates on its axis, making one complete rotation from west to east every 24 hours.

From From TILTTILT to SEASONS to SEASONS As the Earth travels around the Sun, the As the Earth travels around the Sun, the tilttilt

changes in relation to the Sun. Sometimes changes in relation to the Sun. Sometimes ““towardtoward”” the Sun, sometimes the Sun, sometimes ““awayaway””, and , and sometimes neither. sometimes neither.

This creates a This creates a predictable predictable

cycle of cycle of warmer and warmer and

cooler periods, cooler periods, or seasons.or seasons.

Section 1Section 1• While Earth is rotating on its axis, it is also

traveling in an orbit around the sun—this revolution takes 365 days to complete.

• The Earth’s revolution and tilt cause changes in the angle and amount of sunlight that reach different locations on the planet, also known as seasons.

Climate and Weather (cont.)

Effects of Earth’s Tilt

SeasonsSeasons Because the direction of the tilt (Because the direction of the tilt (““towardstowards”” or or

““awayaway””) is opposite for the Northern and ) is opposite for the Northern and Southern hemispheres, so are the seasons.Southern hemispheres, so are the seasons.

Here is the rule to remember… Tilted “toward” the Sun means Summer, tilted “away” from the Sun means winter

Solstice and EquinoxSolstice and Equinox SolSolsticestice – the point at which the Earth is pointed farthest – the point at which the Earth is pointed farthest

toward / away from the Sun, creating toward / away from the Sun, creating long summer days and long summer days and short winter daysshort winter days . (Latin root word . (Latin root word ““solsol””))– Summer – around June 21Summer – around June 21– Winter – around December 21Winter – around December 21 EquinoxEquinox – the – the

point at which the point at which the Earth is not Earth is not pointed toward OR pointed toward OR away from the away from the Sun, creating Sun, creating equalequal day and day and nightnight. . ((““equi-noxequi-nox””))-Spring (“Vernal”)around March 21- Fall (“autumnal”) around Sept. 21

Section 1Section 1Climate and Weather (cont.)

• The Tropics of Cancer and Capricorn

– When the sun’s rays directly strike the Tropic of Cancer, this marks the beginning of summer in the Northern Hemisphere.

– When the sun’s rays directly strike the Tropic of Capricorn, this marks the beginning of winter in the Northern Hemisphere.

Section 1Section 1Climate and Weather (cont.)

• The Poles

– At the North Pole, the sun never sets from about March 20 to September 23.

– At the South Pole, the sun never sets from about September 23 to March 20.

The Earth’s Seasons

What are the Tropics?What are the Tropics?

When we think of the tropics, we thing of When we think of the tropics, we thing of warm, humid weather and great beaches!warm, humid weather and great beaches!

Although this is true, the term comes from Although this is true, the term comes from the area of the earth that lies between the the area of the earth that lies between the two lines of latitude that are called the two lines of latitude that are called the Tropic of Cancer and the Tropic of Tropic of Cancer and the Tropic of Capricorn. These areas tend to be warm, Capricorn. These areas tend to be warm, humid, green and beautiful.humid, green and beautiful.

The Tropic of Cancer is found at 23 ½ The Tropic of Cancer is found at 23 ½ degrees North Latitudedegrees North Latitude

The Tropic of Capricorn is found at 23 ½ The Tropic of Capricorn is found at 23 ½ degrees South Latitudedegrees South Latitude

Section 1-GTRSection 1-GTR

A. Tropic of Cancer

Earth-Sun Relationships

B. Tropic of Capricorn

Section 1Section 1

The Earth rotates on its axis, making one complete rotation every

A. Month

B. 24 hours

C. 365 days

Earth-Sun Relationships

EarthEarth’’s s tilttilt affects length of days affects length of days Places experiencing summer Places experiencing summer

have have ““longerlonger”” days days (more sunlight per 24 hrs.)(more sunlight per 24 hrs.)

Places experiencing winter Places experiencing winter have have ““shortershorter”” days days (less sunlight per 24 hrs.) (less sunlight per 24 hrs.)

Areas above 66 ½ degrees Areas above 66 ½ degrees N or S will experience 24 hr. N or S will experience 24 hr. extremes (light and dark) extremes (light and dark) depending on the seasondepending on the season

(Land of the Midnight Sun)(Land of the Midnight Sun)

24hrs.of

darkfromMayto

August

24hrs.of

lightfromNov.

toFeb.

LongerSummer

days

ShorterWinterdays

Section 1Section 1

The imaginary line running from the North Pole to the South Pole through the planet’s center is known as which term?

A. Equator

B. Solstice

C. Axis

D. Equinox

Section 1Section 1

The natural process of the greenhouse effect has been influenced by human activity.

The Greenhouse Effect

• Like the glass in a greenhouse, the atmosphere traps some heat and keeps it from escaping back into space too quickly so that the Earth is warm enough to maintain life.

Section 1Section 1The Greenhouse Effect (cont.)

• Many scientists claim that in recent decades a rise in atmospheric carbon dioxide levels has coincided with a general rise in global temperatures, also known as global warming.

The Greenhouse Effect

Greenhouse EffectGreenhouse Effect

Normally, when the Sun’s energy penetrates the atmosphere, some of it is absorbed, and some of it is reflected back to space.

Human and natural events increase pollutants that trap the reflected energy and send it back to the Earth again, increasing the Earth’s heat.

Section 1Section 1

Which of the following do you think has caused global warming?

A. A natural cycle

B. Human activity

C. Both

D. Neither