Tom Marchitto

Tom Marchitto

Fellow of INSTAAR

  • Professor, Dept. of Geological Sciences
  • Affiliate Faculty, Dept. of Atmospheric and Oceanic Sciences
  • Associate Editor, Geochimica et Cosmochimica Acta



  • PhD: Marine Geology and Geophysics, MIT-Woods Hole Oceanographic Institution Joint Program, 1999
  • BS: Geology and Geophysics, Yale University, 1994

Contact Information

(Office) 303 492-7739


Paleoceanography and paleoclimatology
ICP-MS Trace Metal Lab

Research Interests

Past abrupt climate change, ocean circulation, ocean biogeochemistry, marine carbon cycle, trace and minor elements in biogenic calcium carbonates, biomineralization

Tom Marchitto on Google Scholar

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Graduate students assist with retrieval of a gravity core aboard the R/V Knorr in the Florida Straits. This coring device is useful for obtaining records of relatively recent climate, typically spanning some tens of thousand of years. Photo credit: Tom Marchitto.

As human activities continue to alter Earth’s climate, it becomes increasingly important to look to the past to better understand the future. I am a paleoceanographer, studying large-scale changes in ocean circulation and biogeochemistry that occur over timescales ranging from a few years to millions of years. Major variations in ocean circulation, from the surface to abyssal depths, have influenced climate via the transport and storage of heat. The oceans also exert control over atmospheric levels of carbon dioxide, an important greenhouse gas. Such changes are reflected in the physical and chemical properties of seawater, including temperature, salinity, carbonate chemistry, radiocarbon age, and the concentrations of various nutrients. I use the chemistry of marine calcifiers, mainly foraminifera, as recorders of these properties.

I grew up in the geologically fascinating state of Connecticut, and was the first member of my family to attend college. Since collecting minerals and fossils were favorite hobbies of my youth, I decided to major in geology at Yale University. I did undergraduate research with geochemist Karl Turekian and micropaleontologist Kuo-Yen Wei. It was only natural to combine these two fields in my pursuit of a PhD in the MIT – Woods Hole Oceanographic Institution Joint Program. My principal advisors there were paleoceanographers Bill Curry and Delia Oppo, and Ed Boyle was also an important mentor. I then spent a bit over three years at the Lamont-Doherty Earth Observatory, working with a tremendous group of scientists that included my post-doctoral advisor Jean Lynch-Stieglitz, Lex van Geen, Peter deMenocal, Gerard Bond, Sidney Hemming, and Wally Broecker. I have been teaching at CU Boulder since 2003.


  • College Scholar Award, University of Colorado Boulder, 2017
  • Kavli Frontiers of Science Fellow, National Academy of Sciences, 2013
  • Provost's Faculty Achievement Award, University of Colorado Boulder, 2008


Research Statement

Paleoceanographers deploy a multicorer aboard the R/V Knorr in the Florida Straits. This coring device is designed to capture multiple undisturbed samples of the sediment-water interface. Photo credit: Tom Marchitto.

Selected current projects:

Timing and Paleoceanographic Impacts of the Onset of Arctic-Baffin Bay Throughflow
PI: Anne Jennings; co-PIs: John Andrews, Alex Jahn, Tom Marchitto, Julio Sepulveda; Postdocs: Lineke Woelders, Hannah Zanowski
We are using numerical modeling and multi-proxy analyses of sediment cores from northern Baffin Bay to discover the timing and consequences of the Holocene (post-glacial) opening of the western gateway for Arctic freshwater to the Labrador Sea. We hypothesize that the establishment of this connection through the Canadian archipelago was important for the Atlantic meridional overturning circulation (AMOC) and the development of the North Water Polynya. Supported by NSF OPP Arctic Natural Sciences (2018-2021).

FORABOT: An Autonomous and Accessible System for Sorting Foraminifera
Collaborative PIs: Edgar Lobaton, Tom Marchitto
We are developing an autonomous sorting system for foraminifera, which will be accessible (in terms of usability and cost) to the scientific community. The automated identification of forams to the species level is accomplished using machine learning, developed under our prior NSF grant "A Visual System for Autonomous Foraminifera Identification." The current system makes use of micromanipulation and microfluidics to facilitate the transport of forams from a hopper to their sorted receptacles. Supported by NSF OCE Ocean Technology and Interdisciplinary Coordination (2016-2018 & 2019-2021).

Development of Individual Foraminiferal Mg/Ca to Reconstruct Past ENSO Variability
PI: Tom Marchitto; PhD student: Brigitta Rongstad
Supported by NSF OCE Paleo Perspectives on Climate Change (2016-2018).

Active Research

Research Programs

Research Labs and Groups



Brigitta RongstadTom Marchitto, Serrato Marks, G., Koutavas, A., Mekik, F., Ravelo, A. C. 2020: Investigating ENSO‐related temperature variability in equatorial Pacific core‐tops using Mg/Ca in individual planktic foraminifera. Paleoceanography and Paleoclimatology, 35(2): e2019PA003774. DOI: 10.1029/2019PA003774

Wycech, J. B., Gill, E., Rajagopalan, B., Tom Marchitto, Molnar, P. H. 2020: Multiproxy reduced‐dimension reconstruction of Pliocene equatorial Pacific sea surface temperatures. Paleoceanography and Paleoclimatology, 35(1): e2019PA003685. DOI: 10.1029/2019PA003685

Piasecki, A., Bernasconi, S. M., Grauel, A.-L., Hannisdal, B., Ho, S. L., Leutert, T. J., Tom Marchitto, Meinicke, N., Tisserand, A., Meckler, N. 2019: Application of clumped isotope thermometry to benthic foraminifera. Geochemistry, Geophysics, Geosystems, 20(4): 2082-2090. DOI: 10.1029/2018GC007961

Mitra, R., Tom Marchitto, Ge, Q., Zhong, B., Kanakiya, B., Cook, M. S., Fehrenbacher, J. S., Ortiz, J. D., Tripati, A., Lobaton, E. 2019: Automated species-level identification of planktic foraminifera using convolutional neural networks, with comparison to human performance. Marine Micropaleontology, 147: 16-24. DOI: 10.1016/j.marmicro.2019.01.005

Waelbroeck, C., and 62 others including, Tom Marchitto 2019: Consistently dated Atlantic sediment cores over the last 40 thousand years. Scientific Data, 6: article 165. DOI: 10.1038/s41597-019-0173-8

Mellon, S., Kienast, M., Algar, C., deMenocal, P., Kienast, S. S., Tom Marchitto, Moros, M., Thomas, H. 2019: Foraminifera trace anthropogenic CO2 in the NW Atlantic by 1950. Geophysical Research Letters, 46: 14683-14691. DOI: 10.1029/2019GL084965

Valley, S. G., Lynch-Stieglitz, J., Tom Marchitto 2019: Intermediate water circulation changes in the Florida Straits from a 35 ka record of Mg/Li-derived temperature and Cd/Ca-derived seawater cadmium. Earth and Planetary Science Letters, 523: 115692. DOI: 10.1016/j.epsl.2019.06.032

Tom Marchitto, Bryan, S. P., Whitney Doss, McCulloch, M. T., Montagna, P. 2018: A simple biomineralization model to explain Li, Mg, and Sr incorporation into aragonitic foraminifera and corals. Earth and Planetary Science Letters, 481: 20-29. DOI: 10.1016/j.epsl.2017.10.022

All publications by Tom Marchitto >



Current Courses

  • GEOL 5430: Paleoceanography and Paleoclimatology (alternate Falls)
    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 core and other continental archives will also be discussed. Course will cover the Cretaceous Period to the present, with particular emphasis on the past 150,000 years (the last ice age cycle). Prereq., intro geology or equivalent. Recommended prereq., intro oceanography or atmospheric science.

Past Courses

Postdocs & Students






American Journal of Science
Annual Review of E&PS
Chemical Geology
Climate Dynamics
Climate of the Past
Climatic Change
Deep Sea Research I
Deep Sea Research II
Earth and Planetary Science Letters
Geochimica et Cosmochimica Acta
Geophysical Research Letters
Global Biogeochemical Cycles
The Holocene
Journal of Climate
JGR Atmospheres
JGR Oceans
Journal of Physical Oceanography
Journal of Quaternary Science
Marine Chemistry
Marine Geology
Marine Micropaleontology
Nature Geoscience
Progress in Oceanography
Quaternary Research
Quaternary Science Reviews

Chinook Catalog
Interlibrary Loan
Web of Science