Intro to Earth Interaction With Sun

8/2/2019 Intro to Earth Interaction With Sun

1/20

SIT ONLY WHERE

THERE IS A YELLOWSTICKY NOTE

Get ready for notes


2/20

Physical Geography

http://video.about.com/geography/What-Is-

.htm
http://video.about.com/geography/What-Is-Physical-Geography-.htmhttp://video.about.com/geography/What-Is-Physical-Geography-.htm


3/20

Introduction

The Sun is the primary source of

energy for Earths climate system. Sunlight reaching the Earth can heat

the land, ocean, and atmosphere.

Some of that sunlight is reflectedback to space by the surface, clouds,or ice.

Much of the sunlight that reachesEarth is absorbed and warms theplanet.


4/20

When Earth emits the same amountof energy as it absorbs, its energy

budget is in balance, and its averagetemperature remains stable.


5/20

Milankovitch Cycles

Milankovich cycles are cycles inthe Earth's orbit that influencethe amount of solar radiation

striking different parts of theEarth at different times of year.

May 28, 1879 December 12, 1958


6/20

Milankovitch

Milankovitch is best known for thetheory that bares his name.

The Milankovitch Theory, otherwiseknown as the astronomical theory ofclimate change, it is an explanationof the seasonal changes the result

changes in the Earths orbit aroundthe Sun.


7/20

Milankovitch

He determined that three differentorbital cycles had influence over theseasons and the amount of seasonal

intensity.

Seasonal Intensity refers to thedifference between seasons.

Increased seasonal intensity wouldresult in cold winters and hotsummers.


8/20

What angle is the Earthcurrently tilted at?


9/20

23.5 Tilt


10/20

Obliquity

42,000 year cycle the earth wobbles

angle of the Earth axis varies between

22.1 and 24.5 . Less of an angle than our current 23.5

means less seasonal differences

between the Northern and SouthernHemispheres

greater angle means greater seasonal

differences (i.e. a warmer summer and
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


11/20

Obliquity
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


12/20

Precession
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


13/20


14/20

Precession

Currently the axis of the earthaligned with the North Star or Polaris.

In ~12,000 years the axis of theearths alignment will change andthe North star will be Vega.

What will happen to our climate/
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


15/20

Precession

Approximately 12,000 years fromnow the Northern Hemisphere willexperience summer in December

and winter in June
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


16/20

Eccentricity
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


17/20

Eccentricity

Eccentricity is the change in theshape of the earth's orbit around thesun

Currently, our planet's orbit is almosta perfect circle

Currently only about a 3% differencein distance between the time whenwe're closest to the sun (perihelion)and the time when we're farthest

from the sun (aphelion).
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif


18/20

Perihelion occurson January 3

The earth is 91.4million milesaway from the

sun.

At aphelion, July

4, the earth is94.5 millionmiles from the

sun.


19/20

95,000 year cycle, the earth's orbitaround the sun changes from a thinellipse (oval) to a circle and backagain.

currently the 3million miledifference in distance doesn't changethe amount of solar energy wereceive much.

What do you think will happen whenthe earths orbit around the sunchanges to an oval?


20/20

Answer Questions inNotebook

1. Who is Milankovich?

2. What are the name of the 3cycles he talked about?

3. Describe the 3 cycles fromquestion 2. Include how long thecycle takes and what is occurringduring the cycle.

4. What is perihelion andaphelion?
http://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gifhttp://earth.usc.edu/classes/geol150/stott/variability/images/orbit/obl_anim.gif

Documents

Intro to Earth Interaction With Sun