GEOG 108 Lecture 8.docx

GEOG 108 Lecture 8.docx - GEOG 108 – Sept 21 2018 Solar...

  • No School
  • AA 1
  • 17

This preview shows page 1 - 5 out of 17 pages.

GEOG 108 – Sept. 21, 2018 - Solar output and the earth o Almost all of the energy that drives the various systems (weather and climate, ecosystems, hydrologic cycle, etc.) found on the earth comes from the sun o Solar energy is created at the core of the sun when hydrogen atoms are fused into helium by nuclear fusion o The radiative surface of the sun, or photosphere , has an average temperature of about 5800 kelvins o Total quantity radiation emitted from the sun’s surface is approximately 64,000,000 Wm^-2 o Much of the radiation the sun emits lies in the visible band centred at 0.5
Image of page 1

Subscribe to view the full document.

o Energy emitted by the sun becomes less intense as it travels through space o When it reaches earth, the intensity of the suns radiation is about 1370 Wm^-2 o This value was once called the Solar Constant - Sunspots, Prominences, and Solar Flares o Output of the sun is not constant o Sunspot activity is correlated to solar emission (more = higher output) o Some researchers – variations in the average global temperature over the last few centuries are caused by the sun o Solar flares can cause problems
Image of page 2
- Earth geometry and motions o Reception of solar radiation by the earth’s surface is influenced by a number of geometric relationships o These relationships operate at variety different time scales (hours to several thousand years) o One of the geometric relationships (earth axis tilt) is responsible for the seasons - Earth rotation and revolution o The term earth rotation refers to the spinning of the earth on its axis o One rotation takes exactly 24 hours – called a mean solar day o From the north pole the direction of rotation is counter clockwise o Opposite is true from the south pole
Image of page 3

Subscribe to view the full document.

o Orbit of the earth around the sun is called earth revolution o This celestial motion takes 365.25 days for one cycle o
Image of page 4
Image of page 5
  • Fall '19

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern