Constraining hydrological cycle characteristics of early eocene hyperthermals
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Constraining Hydrological Cycle Characteristics of Early Eocene Hyperthermals   . Srinath Krishnan. Reasons for study. Rainfall has direct impact on human society Impact of anthropogenic activity on rainfall patterns is not well understood

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Constraining hydrological cycle characteristics of early eocene hyperthermals

Constraining Hydrological Cycle Characteristics of Early Eocene Hyperthermals   

Srinath Krishnan


Reasons for study

Reasons for study

  • Rainfall has direct impact on human society

  • Impact of anthropogenic activity on rainfall patterns is not well understood

  • Modern studies suggest intensification of hydrological cycle with warming

    • Wet Wetter

    • Dry Dryer

  • Lack of data inhibits validation of these models in a complex natural system


Reasons for study1

Reasons for study

  • Rainfall has direct impact on human society

  • Impact of anthropogenic activity on rainfall patterns is not well understood

  • Modern studies suggest intensification of hydrological cycle with warming

    • Wet Wetter

    • Dry Dryer

  • Lack of data inhibits validation of these models in a complex natural system


Reasons for study2

Reasons for study

  • Rainfall has direct impact on human society

  • Impact of anthropogenic activity on rainfall patterns is not well understood

  • Modern studies suggest intensification of hydrological cycle with warming

    • Wet Wetter

    • Dry Dryer

  • Lack of data inhibits validation of these models in a complex natural system


Reasons for study3

Reasons for study

  • Rainfall has direct impact on human society

  • Impact of anthropogenic activity on rainfall patterns is not well understood

  • Modern studies suggest intensification of hydrological cycle with warming

    • Wet Wetter

    • Dry Dryer

  • Lack of data inhibits validation of these models in a complex natural system


Early eocene hyperthermals

Early Eocene Hyperthermals

Paleocene-Eocene Thermal Maximum

  • ~3-50C rise in temperature

  • Negative carbon isotope excursion of 2.5-6‰

    Eocene Thermal Maximum-2

  • Smaller rise in temperature compared to the PETM set on a warming trend

  • Carbon isotopic excursion about half of the PETM

Adapted from Zachos et al. (2001)


Early eocene hyperthermals1

Early Eocene Hyperthermals

  • Causes

    • Methane Hydrates (Dickens et al., 1995)

    • Burning of terrestrial organic matter (Kurtz et al., 2003)

  • Estimates of greenhouse gas concentrations

    • Pre-PETM: ~600 – 2,800 ppm of CO2

    • PETM: ~750 – 26,000 ppm of CO2

      • ~1,500 – 55,000 Gt C in the atmosphere

      • ~3,900 – 57,000 Gt C released in the oceans

  • Modern atmospheric CO2 concentration: ~360 ppm

  • Modern Conventional fossil fuel reserves: ~5,000 Gt C


Early eocene hyperthermals2

Early Eocene Hyperthermals

  • Causes

    • Methane Hydrates (Dickens et al., 1995)

    • Burning of terrestrial organic matter (Kurtz et al., 2003)

  • Estimates of greenhouse gas concentrations

    • Pre-PETM: ~600 – 2,800 ppm of CO2

    • PETM: ~750 – 26,000 ppm of CO2

      • ~1,500 – 55,000 Gt C in the atmosphere

      • ~3,900 – 57,000 Gt C released in the oceans

  • Modern atmospheric CO2 concentration: ~360 ppm

  • Modern Conventional fossil fuel reserves: ~5,000 Gt C


Constraining hydrological cycle characteristics of early eocene hyperthermals

GOAL

  • Use early Eocene hyperthermals as analogues to study changes in the hydrological cycle during extreme warming events


Schematic of a water cycle

Schematic of a Water Cycle

Adapted from NASA Goddard Flight Center


Expected changes with warming

Expected changes with warming

  • Increased lower tropospheric water vapor

  • In the extra-tropics, the important components of the hydrological cycle that affect isotopic signals are

    • Horizontal poleward flow of moisture

    • Changes in precipitation and evaporation

Dr. Raymond Schmitt: http://www.whoi.edu/sbl/liteSite.do?litesiteid=18912&articleId=28329


Variations in precipitation with warming

Variations in Precipitation with warming

2.80c in 2100

Increased

Evaporation

Held and Soden (2006)


Variations in precipitation with warming1

Variations in Precipitation with warming

2.80c in 2100

Increased Precipitation

Held and Soden (2006)


Isotopes and precipitation

Isotopes and Precipitation


Modern annual precipitation

Modern annual precipitation

http://www.waterisotopes.org


Rayleigh distillation

Rayleigh Distillation

Clark and Fritz, 1997


Rayleigh distillation1

Rayleigh Distillation

Increased depletion with progressive rainout events

Clark and Fritz, 1997


Hypotheses

Hypotheses

  • There is a systematic change in moisture transport to the higher latitudes during warming events

    • Are there similar changes in δD between the two hyperthermals at the higher latitudes?

    • Can these changes be detected on a global scale?

    • Can this theoretical model be reproduced with an isotope coupled climate model?


Proxies

Proxies

  • n-alkanes: Single chain hydrocarbon with long chain lengths (n-C23-35) indicating terrestrial plant/leaf wax sources

    • Compound-specific hydrogen isotopic composition represents meteoric water modified by evapotranspiration

    • Compound-specific carbon isotopic compositions represents environmental and ecological conditions


Proxies1

Proxies

  • n-alkanes: Single chain hydrocarbon with long chain lengths (n-C23-35) indicating terrestrial plant/leaf wax sources

    • Compound-specific hydrogen isotopic composition represents meteoric water modified by evapotranspiration

    • Compound-specific carbon isotopic composition represents environmental and ecological conditions


N alkanes and precipitation

n-alkanes and precipitation

Deuterium

n-alkanes

Adapted from Sachse et al., 2006)


Biomarker transport

Biomarker transport

Continent

Oceans

Aerosols

(with waxes)

Wind

Terrestrial Plants

Rivers

Adapted from Eglinton and Eglinton, 2008


Methods

Methods

Samples

Crushing and Extraction

Total Lipid Extract

Compound Separation

n-alkane and biomarker fractions

Clean-up Procedures

Gas Chromatogram

Analyses

Compound Detection & Identification

Compound-specific Isotope

Ratio Mass Spectrometer

Compound-specific Deuterium & Carbon isotope compositions

Analytical Uncertainty: ±5‰


Iodp 302 arctic coring expedition

IODP-302 Arctic Coring Expedition


Arctic paleocene eocene thermal maximum

Arctic Paleocene-Eocene Thermal Maximum

~55.6 Ma

Duration: ~150-200 kyrs

Modified from Pagani et al., 2006


Arctic eocene thermal maximum 2

Arctic Eocene Thermal Maximum-2

~54 Ma

Duration: ~75-100 kyrs

This work


Preliminary conclusions

Preliminary Conclusions

  • Enrichment at the onset for both events with different magnitudes

    • Decreased rainout for moisture reaching the poles

  • 15-20‰ magnitude depletions during the events

    • Similar variations during both the events


Preliminary conclusions1

Preliminary Conclusions

  • Enrichment at the onset for both events with different magnitudes

    • Decreased rainout for moisture reaching the poles

  • 15-20‰ magnitude depletions during the events

    • Similar variations during both the events


Hypotheses1

Hypotheses

  • There is a systematic change in moisture transport to the higher latitudes during hyperthermal events

    • Are there similar changes in δD during the two hyperthermals at the higher latitudes?

    • Preliminary Conclusion: Enrichments in δD do correspond with the hyperthermals at the onset of the event with similar magnitude depletions during the event

Number of samples

Arctic ETM-2: 29 samples


Hypotheses2

Hypotheses

  • There is a systematic change in moisture transport to the higher latitudes during hyperthermal events

    • Are there similar changes in δD during the two hyperthermals at the higher latitudes?

    • Can these changes be detected on a global scale?

    • Can this theoretical model be reproduced with an isotope coupled climate model?


Tropical petm tanzania handley et al 2008

Tropical PETM: Tanzania (Handley et al., 2008)


Tropical petm colombia this work

Tropical PETM: Colombia (This work)


Mid latitudes petm bighorn basin smith et al 2006

Mid-latitudes PETM: Bighorn Basin Smith et al. (2006)


Petm high latitudes pagani et al 2006

PETM: High LatitudesPagani et al. (2006)


Summary of changes during petm

Summary of changes during PETM

  • Tropics

    • Tanzania – 15‰ enrichment

    • Colombia - ~30‰ depletion

  • Mid-latitudes

    • Lodo – No change during the event with hints of depletion at the onset and the end

    • Bighorn Basin – No significant change

    • Forada - ~10‰ enrichment at the onset followed by a10‰ depletion during the event

  • High Latitudes

    • Arctic – 60‰ enrichment at the onset followed by 20‰ depletion through the event


Summary of changes during petm1

Summary of changes during PETM

  • Tropics

    • Tanzania – 15‰ enrichment

    • Columbia - ~30‰ depletion

  • Mid-latitudes

    • Lodo, California – No change during the event with hints of depletion at the onset and the end

    • Bighorn Basin – No significant change

    • Forada, Italy - ~10‰ enrichment at the onset followed by a10‰ depletion during the event

  • High Latitudes

    • Arctic – 60‰ enrichment at the onset followed by 20‰ depletion through the event


Summary of changes during petm2

Summary of changes during PETM

  • Tropics

    • Tanzania – 15‰ enrichment

    • Columbia - ~30‰ depletion

  • Mid-latitudes

    • Lodo – No change during the event with hints of depletion at the onset and the end

    • Bighorn Basin – No significant change

    • Forada - ~10‰ enrichment at the onset followed by a10‰ depletion during the event

  • High Latitudes

    • Arctic – 60‰ enrichment at the onset followed by 20‰ depletion through the event


Hypotheses3

Hypotheses

  • There is a systematic change in moisture transport to the higher latitudes during hyperthermal events

    • Can these changes be detected on a global scale?

    • Preliminary Conclusion: Existing data not sufficient to draw conclusions about regional & hemispherical changes. Requires further studies on a global scale


Ongoing work

Ongoing Work


Ongoing work giraffe core

Ongoing Work: Giraffe Core

C29


Ongoing work 1051

Ongoing Work: 1051

C29


Ongoing work 1263

Ongoing Work: 1263

C29


Ongoing work 690

Ongoing Work: 690

C29


Hypotheses4

Hypotheses

  • There is a systematic change in moisture transport to the higher latitudes during hyperthermal events

    • Are there similar changes in δD during the two hyperthermals at the higher latitudes?

    • Can these changes be detected on a global scale?

    • Can these changes predicted be reproduced with an isotope coupled climate model?


Future work eocene modeling

Future Work: Eocene Modeling

  • Goal

    • To utilize the global dataset developed to compare the hydrological response in terms of isotopes, temperatures and precipititation signals

  • Simulations planned

    • Hyperthemal scenarios (PETM vs. ETM2)

    • Different CO2 concentrations

    • Background Eocene


Thank you

Thank You

Acknowledgments

Joint Oceanographic Institute, ODP/IODP

Mark Pagani, Matt Huber, Appy Sluijs, Carlos Jaramillo

Peter Douglas, Sitindra Dirganghi, Micheal Hren, Brett Tipple, Katie French, Keith Metzger, Courtney Warren, Matt Ramlow, Gerry Olack, Dominic Colosi

Yale G&G Faculty, Staff & Students


Mid latitudes petm forada tipple unpublished

Mid-latitudes PETM: Forada Tipple (unpublished)


Mid latitudes petm lodo tipple unpublished

Mid-latitudes PETM: Lodo Tipple (unpublished)


Paleogeography

Paleogeography


C 3 biosynthetic pathway

C-3 Biosynthetic pathway


C 4 biosynthetic pathway

C-4 Biosynthetic pathway


Modern mean annual poleward flux

Modern mean annual poleward flux


Changes in northward polar flux with doubling of co2 ipcc ar 4 scenario

Changes in northward polar flux with doubling of CO2 – IPCC AR-4 scenario

Held & Soden, 2006


Proxies2

Proxies

  • TEX-86

    • Derived from marine pico plankton Crenarchaeota

    • Vary membrane fluidity and composition depending on the temperature

    • Has recently been applied to analyze paleo-SST


Changes in gwml

Changes in GWML


Theoretical model

Theoretical Model

  • Warming results in increased lower tropospheric water vapor

  • Scales according to the Clausius-Clayperon relationship

  • In the extra-tropics, the important components of the hydrological cycle that affect isotopic signals are horizontal poleward flow of moisture and changes in precipitation and evaporation

  • Simple models have been developed by scaling with the Clausius-Clayperon relation


Energy use phase

Energy Use Phase


Energy generation phase

Energy generation Phase


Constraining hydrological cycle characteristics of early eocene hyperthermals

FATTY ACID BIOSYNTHESIS

PYRUVATE

ACETOACETYL-ACP

NADPH

CO2

H2O

ACETYL CO-A

BUTYRYL-ACP

ACETYL CO-A

6 × MALONYL CO-A

CO2

MALONYL CO-A

CO2

PALMITATE

(16:0 FATTY ACID)


Constraining hydrological cycle characteristics of early eocene hyperthermals

ISOPRENOIDBIOSYNTHESIS

NON-MVA-PATHWAY

MVA-PATHWAY

2×ACETYL CO-A

PYRUVATE

GLYCERAL-DEHYDE-3P

ACETOACETYL CO-A

ACETYL CO-A

-CO2

DEOXY-XYLULOSE-P

3-HYDROXY-3-METHYL GLUTARATE

METHYL ERYTHROSE-P

2NADPH

NADPH

METHYL ERYTHRITOL-P

MEVALONATE DIPHOSPHATE

H2O

-CO2

ISOPENTENYL DIPHOSPHATE

ISOPENTENYL DIPHOSPHATE

2NADPH


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