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Antarctic and Greenland Ice Cores. Glacial-Interglacial Variability Records of the Pleistocene Ice Ages. 740 kyr - Present. Vostok. European Project for Ice Coring in Antarctica (EPICA). Ice Coring. Temperature and Greenhouse Gases from Ice Core Records.

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Antarctic and Greenland Ice Cores

Glacial-Interglacial VariabilityRecords of the Pleistocene Ice Ages

  • 740 kyr - Present

Vostok

European Project for Ice Coring in Antarctica (EPICA)



Temperature and greenhouse gases from ice core records

Temperature and Greenhouse Gases from Ice Core Records

Oxygen isotopes from benthic forams are a proxy for ice volume

  • Greenhouse Gases trapped in air bubbles:

    Carbon Dioxide (CO2),Methane (CH4),Nitrous Oxide (N2O)

  • Variations of Deuterium (heavy isotope of Hydrogen) used as a proxy for temperature change


Compare to

modern levels:

CO2 (370 ppm)CH4(1750 ppb)

N2O(315 ppb)


How do the Glacial-Interglacial variations in greenhouse gases (GHGs) compare with the Industrial Era GHG increase?


Gray bars gases (GHGs) compare with the Industrial Era GHG increase?

show range

of natural

variability

N2O

CO2

CH4


Homework #9 gases (GHGs) compare with the Industrial Era GHG increase?

Introduction (justification, background?)

Description of Experiments

Description of GCM you are using

Attach print outs of Simulation Summary and Rundeck for all runs you set up

  • Probably about 3 pages single-spaced

  • Use images and references


Glacial/Interglacial Cycles gases (GHGs) compare with the Industrial Era GHG increase?

Orbital Variations and the Ice Ages

(Sea Level Change)


Solar Irradiance Across Latitude and Time gases (GHGs) compare with the Industrial Era GHG increase?

DJF

Ann.

JJA


Orbital Variations gases (GHGs) compare with the Industrial Era GHG increase?

  • Eccentricity

  • Obliquity

  • Precession of the

    Equinoxes

    (OmegaT in EdGCM)

Milankovitch Cycles


Can GCMs simulate the onset of Ice Ages? gases (GHGs) compare with the Industrial Era GHG increase?

  • No

  • Sort of

    Gallimore and Kutzbach (1996) suggested that tundra increase and boreal forest decrease may have helped trigger ice ages.

  • But, not really

    Other models don’t get this result and the distribution of snow accumulation was not correct in G&K

115,000 solar insolation based on orbital parameter changes.

+ reduced CO2

+ ground albedo increase (tundra expansion)

+ more albedo increase

(boreal forest reduction)

Gallimore and Kutzbach, Nature, 1996


Sea Level Rise: Last Glacial Maximum to Present gases (GHGs) compare with the Industrial Era GHG increase?


Sea Level Rise: gases (GHGs) compare with the Industrial Era GHG increase?

1880 - 2000

Sea Level Rise

1880 - 2100


Onset of melting during last interglacial period gases (GHGs) compare with the Industrial Era GHG increase?

  • Last interglacial melting begins (135kyr BP)

  • Max N.H. summer insolation last interglacial (135kyr BP)

  • Most recent interglacial melting begins (15kyr BP)

  • Max N.H. summer insolation current interglacial

    (15kyr BP)

Overpeck et al., Science, 2006


Source of sea level rise during last interglacial gases (GHGs) compare with the Industrial Era GHG increase?

Evidence that West Antarctic Ice Sheet (WAIS) contributed to sea level rise during last interglacial includes ice core temperature data showing a substantial warming over East Antarctica despite the lack of a significant insolation signal at that latitude.

A


GCM Simulations of Climate Change in Greenland and Antarctica:

Last Interglacial & Future Global Warmings

AD2130

Anomaly

(~4xCO2)

Last Interglacial

Anomaly

AD2100

Anomaly

Modern


GCM Simulations of Climate Change in Greenland: Antarctica:

Current Global Warming (EdGCM, GISS Model II)

∆ 2000-04 minus 1958-62


GCM Simulations of Climate Change in Greenland: Antarctica:

Current Global Warming (EdGCM, GISS Model II)

∆ 2000-04 minus 1958-62


GCM Simulations of Climate Change in Greenland: Antarctica:

Current Global Warming (Observations)


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