GEOL 5430 syllabus

GEOL 5430

Paleoceanography and Paleoclimatology

Fall 2018

foraminifera Chinese cave and Greenland ice d18O

Meets: Tuesdays and Thursdays 11:00 am - 12:15 pm, Benson Earth Sciences 265
Professor: Tom Marchitto, tom.marchitto@colorado.edu
Office Hours: Tuesdays 3:00 - 4:30 pm in Benson 435; or by appointment in SEEC S153C

3 Credits
Counts toward the
Graduate Certificate in Oceanography

Introduction: An understanding of the modes and mechanisms of past climate variability is a vital prerequisite for understanding our current and future climate. Past changes in oceanic and atmospheric circulation are known to have far exceeded the range of variability observed during the instrumental period. Such past changes offer important insights into the basic workings of the Earth’s climate, including its carbon cycle. In addition, dramatic paleoclimate shifts have occurred over periods as short as a decade, a time scale of obvious societal interest. Could similar shifts recur in a future 'Greenhouse' world?

Course description: Examines scientific tools, data, and theories related to the dramatically varied past climate of the Earth. Focus will be on marine records of climate change and ocean circulation, but ice cores and other continental archives will also be discussed. Course will cover the Cenozoic Era (66 Ma to present), but with particular emphasis on the Quaternary ice age cycles. Prereq., intro geology or equivalent. Recommended prereq., intro oceanography or atmospheric science.

Grading: 60% homework problems, 10% research pre-proposal, 20% final research proposal, 10% class participation (includes attendance).

Homework: Nine homework assignments will allow students to apply what they have learned in class to practical problems. Math will generally be limited to algebra, plus a little calculus. All assignments are to be handed in during class, and late submissions will lose 10% credit per day (not per class meeting). Students are allowed to work together on assignments as long as that does not entail 'copying.'

Research proposal: Students will write an abbreviated NSF-style research proposal exploring some original topic in paleoceanography or paleoclimatology within the Cenozoic. Proposals should include background information, a testable hypothesis, and a feasible research plan. The assignment will be split into two parts, with a mid-term 'pre-proposal' that the instructor will provide comments on, followed by a final version due near the end of the semester. For the final homework assignment, each student will be required to anonymously review two of their classmates' proposals. Your proposal topic may be relevant to your dissertation research, but it must constitute a legitimately new direction that you haven't already started writing about. It also must not be recycled from some previous course or past research.

Proposal warm-up and project description Warmup due Thurs 10/11, Final proposal due Thurs 11/15
NSF P2C2 Program Description
Web of Science (you may need to register)
Google Scholar

Below is a copy of an NSF proposal that NSF actually funded. I have posted it so that those who have never seen a proposal can see how one might be laid out. The class project certainly need not be so "dense" (I pack a lot of text into those 15 pages), but you can get a sense of how a real proposal is built. Of course this is only one example, and you may like to ask your advisor to see another example. There are two files: one is the one-page summary, and the other is the 15-page description. I have not included the reference list.

Marchitto proposal 1-page summary
Marchitto proposal project description

Reading: Weekly readings will be taken from the research literature and from select textbooks. These will be supplied as links to pdfs, and students are encouraged to build a binder packet or e-packet for the course. Many useful readings will be found in the Encyclopedia of Quaternary Science (2nd Ed.) (EQS), which is available electronically through your university account. Ray Bradley's Paleoclimatology: Reconstructing Climates of the Quaternary (3rd Ed., 2015) is also available electronically. Two other textbooks will be on reserve in both the Earth Sciences Library and the INSTAAR Reading Room, if supplemental reading is desired: Bill Ruddiman's Earth's Climate: Past and Future (1st through 3rd Ed., 2001, 2008, 2014) covers climate mechanisms and history, over the Cenozoic and beyond; and Tom Cronin's Paleoclimates: Understanding Climate Change Past and Present (1st Ed., 2010) focuses on the various timescales and mechanisms of climate change, with emphasis on the Quaternary.


Class Schedule, Reading, and Useful Links

Click on lecture title for PowerPoint file (password-protected), available the afternoon following that class
Links will become live as the semester progresses, and are subject to change
If you find dead links that should be live, try refreshing your browser

T 8/28: Intro to paleoceanography and paleoclimatology
motivation, approaches, dating, timescales of change
Link: NOAA Paleoclimatology database

Th 8/30: Overview of radiative balance and atmospheric circulation
Stefan-Boltzmann law, greenhouse effect, radiative forcings, atmospheric cells and prevailing winds
Reading: see Chapter 2 of Ruddiman, Earth's Climate: Past and Future (only in the 1st and 3rd Editions) if you'd like a basic review

T 9/4: Overview of ocean circulation
temperature and salinity, wind-driven circulation, deep ocean circulation
Reading: see Chapter 2 of Ruddiman, Earth's Climate: Past and Future (only in the 1st and 3rd Editions) if you'd like a basic review

Th 9/6: Milankovitch orbital theory
ice ages, insolation, eccentricity, precession, obliquity
Reading: Berger et al., Astronomical theory of paleoclimates, from EQS, 2013.
Link: Berger and Loutre database of orbital parameters and insolation
Homework 1 due

T 9/11: Oxygen isotopes: Paleotemperature and global ice volume
stable isotope fractionation (inorganic), mass spectrometry, Emiliani curve, hydrologic Rayleigh fractionation
Landmark Reading: Dansgaard and Tauber, Glacier oxygen-18 content and Pleistocene ocean temperatures, Science, 166: 499-502, 1969.
Reading: Rohling, Oxygen isotope composition of seawater, from EQS, 2013.

Th 9/13: Milankovitch confirmed: Spectral analysis and SPECMAP
Fourier theorem, orbital tuning, SPECMAP stack
Landmark Reading: Hays et al., Variations in the Earth's orbit: Pacemaker of the Ice Ages, Science, 194: 1121-1132, 1976.
Reading: Bassinot, Oxygen-isotope stratigraphy of the oceans, from EQS, 2013.
Link: Lisiecki & Raymo benthic d18O stack
Homework 2 due

T 9/18: Radiocarbon
production and decay, dating complications, calibration, solar forcing
Reading: van der Plicht, Variations in Atmospheric 14C, from EQS, 2013.
Link: CALIB radiocarbon calibration
Link: IntCal13
Link: CSciBox age modeling software project

Th 9/20: Glacial-interglacial sea level history
tectonics, viscoelastics, geoid, U-Th dating, LGM, MIS 5e
Landmark Reading: Fairbanks, A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep ocean circulation, Nature, 342: 637-642, 1989.
Reading: Murray-Wallace, Eustatic sea-level changes - Glacial-interglacial cycles, from EQS, 2013.
Optional Reading: Edwards et al., Uranium-series dating of marine and lacustrine carbonates, Reviews in Mineralogy and Geochemistry, 52: 363-405, 2003.
Optional Reading: Thompson, U-series dating, from EQS, 2013.
Homework 3 due

T 9/25: Marine microfossils and paleoecological factor analysis
foraminifera, Imbrie-Kipp factor analysis, CLIMAP, MARGO
Landmark Reading: CLIMAP Project Members, The surface of the ice-age Earth, Science, 191: 1131-1137, 1976.
Reading: MARGO Project Members, Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum, Nature Geoscience, 2: 127-132, 2009.
Link: Allan Be's planktonic foram photos
Link: CLIMAP LGM atlas
Link: MARGO LGM atlas

Th 9/27: Ocean temperatures from organic geochemistry
salinity and d18O, Uk'37 saturation index, TEX86, IP25
Reading: Sachs et al., Biomarker indicators of past climate, from EQS, 2013.
Homework 4 due

T 10/2: Ocean temperatures from inorganic geochemistry
Gibbs-Helmholtz thermodynamics, Mg/Ca, Sr/Ca, clumped isotopes
Reading: Rosenthal and Linsley, Mg/Ca and Sr/Ca paleothermometry from calcareous marine fossils, from EQS, 2013.
Reading: Eiler, Paleoclimate reconstruction using carbonate clumped isotope thermometry, Quaternary Science Reviews, 30: 3575–3588, 2011.

Th 10/4: Ice cores: Glaciology and water isotopes I
deuterium, plastic deformation, dating, Greenland records
Reading: Brook, Stable isotopes, from EQS, 2013.
Reading: NGRIP Project Members, High-resolution record of Northern Hemisphere climate extending into the last interglacial period, Nature, 431: 147-151, 2004.
Link: Ice core data
Homework 5 due

T 10/9: Ice cores: Water isotopes II
Antarctic records, tropical ice cores, borehole temperatures, thermal fractionation, deuterium excess, d18O2
Reading: EPICA community members, Eight glacial cycles from an Antarctic ice core, Nature, 429: 623-628, 2004.
Reading: EPICA community members, One-to-one coupling of glacial climate variability in Greenland and Antarctica, Nature, 444: 195-198, 2006.

Th 10/11: Ice cores: Ancient atmospheres
bubble formation, CO2, CH4, very old ice, mean ocean temperature
Reading: Luthi et al., High-resolution carbon dioxide concentration record 650,000-800,000 years before present, Nature, 453: 379-382, 2008.
Reading: Ahn and Brook, Atmospheric CO2 and climate on millennial time scales during the last glacial period, Science, 322: 83-85, 2008.
Proposal warm-up due

T 10/16: Glacial-interglacial atmospheric CO2 and ocean chemistry
solubility pump, biological pump, carbonate compensation
Reading: Sigman and Boyle, Glacial/interglacial variations in atmospheric carbon dioxide, Nature, 407: 859-869, 2000.

Th 10/18: Carbon-13 and carbon-14 as carbon cycle tracers
photosynthetic fractionation, air-sea exchange, LGM abyssal carbon storage
Reading: Burke and Robinson, The Southern Ocean’s Role in Carbon Exchange During the Last Deglaciation, Science, 335: 557-561, 2012.
Homework 6 due

T 10/23: Cenozoic atmospheric CO2 and tectonics
d13Corg, d11B, stomata, caliche, BLAG, Tibet
Landmark Reading: Popp et al., The post-Paleozoic chronology and mechanism of 13C depletion in primary marine organic matter, American Journal of Science, 289: 436-454, 1989.
Reading: Pagani et al., The role of terrestrial plants in limiting atmospheric CO2 decline over the past 24 million years, Nature, 460: 85-88, 2009.
Link: Palaeo-CO2 Project

Th 10/25: Millennial-scale climate change and North Atlantic Deep Water
NADW formation, Younger Dryas, Heinrich events, hysteresis
Landmark Reading: Bond et al., Correlation between climate records from North Atlantic sediments and Greenland ice, Nature, 365: 143-147, 1993.
Reading: Stocker, Past and future reorganizations in the climate system, Quaternary Science Reviews, 19: 301-319, 2000.
Reading: Caesar et al., Observed fingerprint of a weakening Atlantic Ocean overturning circulation, Nature, 556: 191-196, 2018.
Link: cGENIE EMIC
Homework 7 due

T 11/1: Passive tracers of deep ocean circulation
Cd/Ca, d13Cas, epsilon Nd
Reading: Marchitto and Broecker, Deep water mass geometry in the glacial Atlantic Ocean: A review of constraints from the paleonutrient proxy Cd/Ca, Geochemistry, Geophysics, Geosystems, 7(12), Q12003, doi:10.1029/2006GC001323, 2006.

Th 11/3: Dynamic tracers of deep ocean circulation
sortable silt, Pa/Th, paleogeostrophy, deep sea T & S
Reading: McManus et al., Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes, Nature, 428: 834-837, 2004.
Reading: Lynch-Stieglitz et al., Weaker Gulf Stream in the Florida Straits during the Last Glacial Maximum, Nature, 402: 644-648, 1999.
Reading: Adkins et al., The Salinity, Temperature, and 18O of the Glacial Deep Ocean, Science, 298: 1769-1773, 2002.
Homework 8 due

T 11/6: Paleo-monsoon and ENSO
African Humid Period, sapropels, Asian monsoon variability, Holocene ENSO
Reading: Wang et al., A high-resolution absolute-dated Late Pleistocene monsoon record from Hulu Cave, China, Science, 294: 2345-2348, 2001.

Th 11/8: Paleocene to Eocene (66-34 Ma): Greenhouse world
PETM, cool tropics paradox
Reading: Zachos et al., Trends, rhythms, and aberrations in global climate 65 Ma to present, Science, 292: 686-693, 2001.

T 11/13: Oligocene to Miocene (34-5 Ma): Descent into the Icehouse
Antarctic glaciation, Monterey Hypothesis, grasslands, Messinian Salinity Crisis
Reading: Pagani et al., Marked decline in atmospheric carbon dioxide concentrations during the Paleogene, Science, 309: 600-603, 2005.
Reading: Cerling, et al., Global vegetation change through the Miocene/Pliocene boundary, Nature, 389: 153-158, 1997.

Th 11/15: Plio-Pleistocene (past 5 Ma): Onset of Northern Hemisphere glaciation
Isthmus of Panama, NADW, 20-40-100 k worlds, hominids
Reading: Raymo et al., Plio-Pleistocene Ice Volume, Antarctic Climate, and the Global d18O Record, Science, 313: 492-495, 2006.
Reading: Huybers and Wunsch, Obliquity pacing of the late Pleistocene glacial terminations, Nature, 434: 491-494, 2005.
Proposal due

T 11/20 & Th 11/22: Fall Break - No class

T 11/27: Holocene (past 10 ka): Relative stability
deglaciation, hypsithermal, neoglaciation
Reading: Kaufman et al., Holocene thermal maximum in the western Arctic (0–180°W), Quaternary Science Reviews, 23: 529-560, 2004.
Reading: Mayewski et al., Holocene climate variability, Quaternary Research, 62: 243-255, 2004.

Th 11/29: Past 1000 yrs: Medieval Warm Period and Little Ice Age
glaciers, forcings, NAO, ENSO, hemispheric reconstruction
Reading: Mann and Jones, Global surface temperatures over the past two millennia, Geophysical Research Letters, 30(15): 1820, 2003.
Reading: Mann et al., Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly, Science, 326: 1256-1260, 2009.

T 12/4 & Th 12/6: PAGES
FCQ week
Homework 9 (proposal reviews) due 12/6 electronically

T 12/11 & Th 12/13: AGU