Post on 12-Feb-2021
transcript
Earth System Modeling in Deep Time
Lee KumpPenn State
Why Deep Time?
J. Kiehl, pers. comm.
“Dead Zones”
Metasequoia log, Stenkul Fiord, Ellesmere Island (photo by Anne Jefferson)
Issues with interpreting deep time
• Discontinuous sedimentation
Hutton’s unconformity, Siccar Point, Scotland(wikipedia.org)
Issues with interpreting deep time
• Diagenesis (post-depositional alteration)
good
bad
Pearson et al. (2001)
Veizer et al. (1999; Chem Geol)
Veizer et al. (1999; Chem Geol)
Typically binned into 10 my “Berner” intervals
Kump and Garrels (1986 AJS)
Kump and Garrels (1986 AJS)
Panchuk et al. (2005)
Barron & Washington (1984 JGR)
Bluth and Kump (1991)
Phanerozoic Paleogeology: what was being weathered where, when?
Gibbs et al. (1999 AJS)
Flux of weathering-derived carbon to the ocean
Today’s pCO2 Paleo-pCO2 Temp corrected
Gibbs et al. (1999 AJS)
Zachos et al. (2001, Science)
Polar temperatures for the last 65 million years
PETM
Published by AAAS
J. C. Zachos et al., Science 308, 1611 -1615 (2005)
Digital core photos and weight % CaCO3 content plotted versus meters of composite depth (MCD) across the PETM on Walvis Ridge
Ying Cui (MS thesis work)
methane
wildfires, nobioturbation
7000 GtCEuropean Space Agency www.esa.int
Peat conflagration (Kurtz et al., 2003)
13C: -22‰
2300 GtCwww.explorecrete.com
Biogenic [clathrate] methane (Dickens, 1995)
13C: -60‰
Panchuk et al. (2007)
CaCO3 wt% model vs. data (circles)
Ying Cui (MS thesis work)
Ying Cui (MS thesis work)
Ying Cui (MS thesis work)
Ying Cui (MS thesis work)
Lovelock and Kump (1994)
Kump and Pollard (2008)
1xPAL pCO2
4xPAL pCO2
4xPAL pCO2 + CCN
Alroy, pers. comm.
Siberian Traps Volcanism(Torsvik, pers. comm.)
Reichow et al. (2009) and Svensen et al(2009)
Hydrogen Sulfide
8x PO43-Panthalassic ocean
Oxygen
8x PO43-
Surface Ocean H2S
H2S (ppbv)
OH (10-3 pptrv)
O3 (ppmv)
Sulfate aerosol density (10-9 cm2/cm3)
Lamarque et al. (2007)
Low High Annual, Zonal Averages
Conclusions
• Paleo community has put the data “back on the map”
• Requires distributed calculations, detailed Model-Data Comparison
• Also shifted focus to geologic events below the “Berner” resolution of 10 m.y.
• From time slices to continuous simulations using EMICs
Conclusions
• EMICs for long simulations dependent on AOGCM fields
• New approaches?
• Lovelock’s Legacy: if biota affected, biotic feedbacks likely
• Alternative Worlds: value of deep-time simulation
Earth System Modeling �in Deep TimeWhy Deep Time?“Dead Zones”Slide Number 4Issues with interpreting deep timeIssues with interpreting deep timeSlide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34ConclusionsConclusions