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What drives the ice age cycles?

What drives the ice age cycles?. Milankovitch Theory of orbital forcing of ice sheets. Tilt variations eccentricity variations precession of perihelion. Axial Tilt. Axial Tilt. Eccentricity. Eccentricity. Precession of Solstices (or Perihelion). Precession of Solstices. Precession.

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What drives the ice age cycles?

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  1. What drives the ice age cycles?

  2. Milankovitch Theory of orbital forcing of ice sheets Tilt variations eccentricity variations precession of perihelion

  3. Axial Tilt

  4. Axial Tilt

  5. Eccentricity

  6. Eccentricity

  7. Precession of Solstices (or Perihelion)

  8. Precession of Solstices

  9. Precession

  10. Precession & eccentricity

  11. Changes in summer insolation

  12. Changes in winter insolation

  13. Low High Latitude NH summer insolation Allows ice sheets to grow from year to year

  14. Milankovitch Theory: Variations in high latitude (65 N) summer insolation combine with climate system feednack processes drives ice sheet growth and retreat on time scales of 10,000 yrs to 100,000 yrs.

  15. High insolation Low insolation

  16. Solar insolation Surface temp albedo Ice volume Bedrock sinking Southern edge Ice height Base ablation

  17. When high latitude NH summer insolation is below the threshold ice sheets grow slowly. When high latitude NH summer insolation is above the threshold ice sheets quickly retreat.  a sawtooth pattern. Gradual buildup and rapid deglaciation.

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