Kristen Krumhardt

Proj Scientist I

Information

Bio

Kristen Krumhardt is a Project Scientist in the Oceanography section of the Climate and Global Dynamics laboratory. She works on modeling biology in the ocean, specifically phytoplankton and zooplankton dynamics, and contributes to development of the ocean ecosystem model in the Community Earth System Model (CESM). Her research is mainly focused on analyzing how climate change and variability influence phytoplankton communities and how this may impact higher trophic levels.

Kristen's current projects include tailoring ocean climate model data for National Marine Sanctuaries around the United States, as well as participating in the Rising Voices, Changing Coasts (RVCC) project that aims to merge Earth system science with Indigenous knowledge. Kristen also has several projects focused on understanding polar marine ecosystems, such as examing variability and changes in food resources for Antarctic marine predators like penguins.

Kristen also enjoys doing scientific art and illustrations - see examples of her work here.

Link to full publication list.

Publications

Publications and Presentations (18)
Title	Source	Date
From nutrients to fish: Impacts of mesoscale processes in a global CESM-FEISTY eddying ocean model framework	Progress in Oceanography	2024-09-01
Anthropogenic climate change drives non-stationary phytoplankton internal variability	Biogeosciences	2023-11-10
Environmental drivers of coccolithophore growth in the Pacific sector of the Southern Ocean	Global Biogeochemical Cycles	2023-11-09
Projections of winter polynyas and their biophysical impacts in the Ross Sea Antarctica	Climate Dynamics	2023-09-23
Spatio-temporal transferability of environmentally-dependent population models: Insights from the intrinsic predictabilities of Adélie penguin abundance time series	Ecological Indicators	2023-06-01
The representation of alkalinity and the carbonate pump from CMIP5 to CMIP6 Earth system models and implications for the carbon cycle	Biogeosciences	2023-04-03
Variability, skipped breeding and heavy‐tailed dynamics in an Antarctic seabird	Journal of Animal Ecology	2022-12-01
The Seasonal-to-Multiyear Large Ensemble (SMYLE) prediction system using the Community Earth System Model version 2	Geoscientific Model Development	2022-08-29
Climate drivers of Southern Ocean phytoplankton community composition and potential impacts on higher trophic levels	Frontiers in Marine Science	2022-08-11
Simulations with the Marine Biogeochemistry Library (MARBL)	Journal of Advances in Modeling Earth Systems	2021-12-01
Identifying global favourable habitat for early juvenile loggerhead sea turtles	Journal of The Royal Society Interface	2021-02-24
Southern ocean calcification controls the global distribution of alkalinity	Global Biogeochemical Cycles	2020-12-01
Estimation of physiological factors controlling carbon isotope fractionation in coccolithophores in photic zone and core‐top samples	Geochemistry, Geophysics, Geosystems	2020-11-01
Summer high‐wind events and phytoplankton productivity in the Arctic Ocean	Journal of Geophysical Research: Oceans	2020-09-28
Reaching 1.5 and 2.0 °C global surface temperature targets using stratospheric aerosol geoengineering	Earth System Dynamics	2020-07-14
Potential predictability of net primary production in the ocean	Global Biogeochemical Cycles	2020-06-08
Coccolithophore growth and calcification in an acidified ocean: Insights from Community Earth System Model simulations	Journal of Advances in Modeling Earth Systems	2019-05-01
Sudden emergence of a shallow aragonite saturation horizon in the Southern Ocean	Nature Climate Change	2019-04-11

Curriculum Vitae

Kristen Krumhardt - Curriculum Vitae

Email: kristenk@ucar.edu Phone: 720-999-6762

Education

Ph.D. in Environmental Studies, University of Colorado at Boulder, 2018.
Master of Science in Biology, University of Southern Maine, 2007.
Bachelor’s of Art in Biological/Pre-medical Illustration, with distinction, Iowa State University, 2003.
- Phi Beta Kappa

Professional Experiences

Project Scientist I, National Center for Atmospheric Research, Boulder, Colorado, U.S.A. 2023-present.
Associate Scientist II, National Center for Atmospheric Research, Boulder, Colorado, U.S.A. 2020-2023.
Post-doctoral Researcher, National Center for Atmospheric Research, Boulder, Colorado, U.S.A. 2018-2020.
Doctoral Research Assistant at University of Colorado Boulder, Boulder, Colorado, U.S.A. 2014-2018.
Research Assistant, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland and University of Geneva, Geneva, Switzerland, 2008-2014.
Laboratory Research Assistant at University of Southern Maine, Portland, Maine, U.S.A. 2005-2007.

Peer-reviewed publications

Krumhardt, K. M., M. C. Long, C. M. Petrik, M. Levy, F. Castruccio, K. Lindsay, E. Romashkova, R. Denechere, Z. Chen, L. Landrum, A.-L. Deppenmeier, G. Danabasoglu, P. Chang. “From nutrients to fish: A novel, high resolution Community Earth System Model simulation linked to a fisheries model.” Progress in Oceanography (2024). doi:10.1016/j.pocean.2024.103314
Sun, R, R. Fay, F. Ventura, B. Şen, C. Barbraud, K. Delord, K. M. Krumhardt, S. Jenouvrier. “Climate change impacts pair-bond dynamics in a long-lived monogamous species.” Submitted to Ecology Letters.
Oliver, H., D. J. McGillicuddy, Jr., K. M. Krumhardt, M. C. Long, N. R. Bates, B. C. Bowler, D. T. Drapeau, W. M. Balch. “Environmental drivers of coccolithophore growth in the Pacific sector of the Southern Ocean.” Global Biogeochemical Cycles (2023). doi:10.1029/2023GB007751
Elsworth, G. W., N. S. Lovenduski, K. M. Krumhardt, T. M. Marchitto, S. Schlunegger. “Anthropogenic climate change drives non-stationary phytoplankton variance.” Biogeosciences (2023). doi: /10.5194/bg-20-4477-2023
DuVivier, A., M. J. Molina, M. M. Holland, L. Landrum, K. M. Krumhardt, S. Jenouvrier. “Projections of winter polynyas and their biophysical impacts in the Ross Sea.” Climate Dynamics (2023). doi:10.1007/s00382-023-06951-z
Bourreau, L., E. Pauthenet, L. Le Ster, B. Picard, E. Portela, J.-B. Sallée, C. Reginald McMahon, R. Harcourt, M. Hindell, C. Guinet, S. Bestley, J.-B. Charrassin, A. DuVivier, Z. Sylvester, K. M. Krumhardt, S. Jenouvrier and S. Labrousse “First description of in situ chlorophyll fluorescence signal within East Antarctic coastal polynyas during fall and winter.” Frontiers in Marine Science (2023). doi:10.3389/fmars.2023.1186403
Planchat, A., L. Kwiatkowski, L. Bopp, O. Torres, J. R. Christian, M. Butenschön, T. Lovato, R. Séférian, M. A. Chamberlain, O. Aumont, M. Watanabe, A. Yamamoto, A. Yool, T. Ilyina, H. Tsujino, K. M. Krumhardt, J. Schwinger, J. Tjiputra, J. P. Dunne, C. Stock. “The representation of alkalinity and the carbonate pump from CMIP5 and CIMP6 Earth system models and implications for the carbon cycle.” Biogeosciences (2023). doi:10.5194/bg-20-1195-2023.
Şen, B., C. Che-Castaldo, K. M. Krumhardt, L. Landrum, M. M. Holland, M. A. LaRue, M. C. Long, S. Jenouvrier, H. J. Lynch. “Spatio-temporal transferability of environmentally-dependent population models: Insights from the intrinsic predictabilities of Adélie penguin abundance time series.” Ecological Indicators (2023). doi:10.1016/j.ecolind.2023.110239
Talis, E. M., C. Che-Castaldo, B. Sen, K. M. Krumhardt, H. J. Lynch. “Variability, skipped breeding and heavy-tailed dynamics in an Antarctic seabird.” Journal of Animal Ecology (2022). doi:/10.1111/1365-2656.13827
Yeager, S. G., N. Rosenbloom, A. A. Glanville, X. Wu, I. Simpson, H. Li, M. J. Molina, K. M. Krumhardt, et al., “The Seasonal-to-Multiyear Large Ensemble (SMYLE) prediction system using the Community Earth System Model version 2.” Geoscientific Model Development. (2022). doi:/10.5194/gmd-15-6451-2022
Krumhardt, K. M., M. C. Long, Z. T. Sylvester, C. M. Petrik. “Climate drivers of Southern Ocean phytoplankton community composition and potential impacts on higher trophic levels.” Frontiers in Marine Science (2022). doi:/10.3389/fmars.2022.916140
Long, M. C., J. K. Moore, K. Lindsay, M. Levy, S. C. Doney, J. Y. Luo, K. M. Krumhardt, R. T. Letscher, M. Grover, Z. T. Sylvester. "Simulations with the Marine Biogeochemistry Library (MARBL)." Journal of Advances in Modeling Earth Systems (JAMES) (2021). doi:/10.1029/2021MS002647
Harrison, C. S., J. Y. Luo, N. F. Putman, Q. Li, P. Sheevam, K. M. Krumhardt, J. Stevens, M. C. Long. "Identifying global favourable habitat for early juvenile loggerhead sea turtles." Journal of the Royal Society Interface (2021). doi:/10.1098/rsif.2020.0799
Krumhardt, K. M., M. C. Long, K. Lindsay, M.N. Levy. "Southern Ocean calcification controls the global distribution of alkalinity." Global Biogeochemical Cycles (2020). doi:/10.1029/2020GB006727
Hernández‐Almeida, I., K. M. Krumhardt, H. Zhang, H. M. Stoll. "Estimation of physiological factors controlling carbon isotope fractionation in coccolithophores in photic zone and core‐top samples." Geochemistry, Geophysics, Geosystems (2020). doi:10.1029/2020GC009272
Crawford, A. D., K. M. Krumhardt, N. S. Lovenduski, G. L. van Dijken, K. R. Arrigo. Summer high‐wind events and phytoplankton productivity in the Arctic Ocean. Journal of Geophysical Research: Oceans (2020). doi: e2020JC016565.
Krumhardt, K. M., N. S. Lovenduski, M. C. Long, J. Y. Luo, K. Lindsay, S. Yeager, C. Harrison. Potential predictability of net primary production in the ocean. Global Biogeochemical Cycles (2020). doi:10.1029/2020GB006531.
Elsworth, Geneviève W., N. S. Lovenduski, K. A. McKinnon, K. M. Krumhardt, Riley X. Brady. Finding the Fingerprint of Anthropogenic Climate Change in Marine Phytoplankton Abundance. Current Climate Change Reports (2020). doi:10.1007/s40641-020-00156-w.
Negrete-García, G. N. S. Lovenduski, C. Hauri, K. M. Krumhardt, S. K. Lauvset. Sudden emergence of a shallow aragonite saturation horizon in the Southern Ocean. Nature Climate Change (2019). doi:10.1038/s41558-019-0418-8.
Krumhardt, K. M., N. S. Lovenduski, M. C. Long, M. Levy, K. Lindsay, J. K. Moore, C. Nissen. Coccolithophore growth and calcification in an acidified ocean: Insights from Community Earth System Model simulations. Journal of Advances in Modeling Earth Systems (JAMES) (2019). doi:10.1029/2018MS001483.
Freeman, N. M., N. S. Lovenduski, D. R. Munro, K. M. Krumhardt, K. Lindsay, M. C. Long, M. Maclennan. The variable and changing Southern Ocean Silicate Front: Insights from the CESM Large Ensemble. Global Biogeochemical Cycles. (2018). doi:10.1029/2017GB005816
Krumhardt, K. M., N. S. Lovenduski, M. D. Iglesias-Rodriguez, J. A. Kleypas. Coccolithophore growth and calcification in a changing ocean. Progress in Oceanography (2017). doi:10.1016/j.pocean.2017.10.007
Krumhardt, K. M., N. S. Lovenduski, M. C. Long, K. Lindsay. Avoidable impacts of ocean warming on marine primary production: Insights from the CESM ensembles. Global Biogeochemical Cycles (2017). doi:10.1002/2016GB005528.
Kaplan, J.O., K.M. Krumhardt, M.J. Gaillard, et al. Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions. Land (2017). doi:10.3390/land6040091
Krumhardt, K. M., N. S. Lovenduski, N. M. Freeman, N. R. Bates. Apparent increase in coccolithophore abundance in the subtropical North Atlantic from 1990 to 2014. Biogeosciences (2016). doi:10.5194/bg-13-1163-2016
He, F., S. J. Vavrus, J. E. Kutzbach, W. F. Ruddiman, J. O. Kaplan, K. M. Krumhardt. Simulating global and local surface temperature changes due to Holocene anthropogenic land cover change. Geophysical Research Letters (2014). doi:10.1002/2013GL058085.

• Krumhardt, K. M., K. Callnan, K. Roache-Johnson, T. Sweet, D. Robinson, E. Nahas Reistetter, J. K. Saunders, G. Rocap, L. R. Moore. Effects of phosphorus starvation versus limitation on the marine cyanobacterium Prochlorococcus MED4 I: uptake physiology. Environmental Microbiology (2013). doi:10.1111/1462-2920.12079

• Nahas Reistetter, E., K. M. Krumhardt, K. Callnan, K. Roache-Johnson, J. K. Saunders, L. R. Moore, G. Rocap. Effects of phosphorus starvation vs. limitation on the marine cyanobacterium Prochlorococcus MED4 II: gene expression. Environmental Microbiology (2013). doi:10.1111/1462-2920.12129

• Kaplan, J. O., K. M. Krumhardt, N. E. Zimmermann. The effects of land use and climate change on the carbon cycle of Europe over the past 500 years. Global Change Biology (2012). doi:10.1111/j.1365-2486.2011.02580.x

• Sapart, C. J., G. Monteil, M. Prokopiou, R. S. W. van de Wal, J. O. Kaplan, P. Sperlich, K. M. Krumhardt, C. van der Veen, S. Houweling, M. C. Krol, T. Blunier, T. Sowers, P. Martinerie, E. Witrant, D. Dahl-Jensen, T. Röckmann. Natural and anthropogenic variations in methane sources during the past two millennia. Nature (2012). doi:10.1038/nature11461

• Kaplan, J. O., K. M. Krumhardt, E. C. Ellis, W. F. Ruddiman, C. Lemmen, K. K. Goldewijk. Holocene carbon emissions as a result of anthropogenic land cover change. The Holocene (2011). doi:10.1177/0959683610386983

Kaplan, J. O., K. M. Krumhardt, N. Zimmerman. The prehistoric and preindustrial deforestation of Europe. Quaternary Science Reviews (2009). doi:10.1016/j.quascirev.2009.09.028

Additional Activities and Outreach

Community Earth System Model (CESM) Biogeochemistry Working Group internal co-chair.
Member of the Scientific Steering Committee for Ocean Carbon & Biogeochemistry (OCB).
Scientific illustrator, Biological Oceanography, by Susanne Menden-Deuer. Publisher: Elsevier, London, 2021-2024.
Science mentor for high school science students, Science Research Seminar Course 2019/2020, 2020/2021, 2021/2022, 2022/2023, Boulder Valley School District.
Co-mentor for undergraduate/graduate students in summer research internship programs (SOARS, RESESS, SIParCS), 2017/2018/2023/2024.
Invited guest lecturer for Spatial Statistics and Analysis, Environmental Studies, Oceanography, and Climate Change courses (2011-2022).

Funded research grants

• NOAA, Pulse of the planet: A climate data decision-support dashboard for National Marine Sanctuary management and participatory adaptation planning. Period of performance: 9/1/2022 to 8/31/2025. Lead PI: Dr. Kelly Dunning (Auburn University), Co-PIs: Deepak Cherian (NCAR), Kristen Krumhardt (NCAR). Amount awarded to NCAR: $254,814

• NOAA, mCDR 2023: Multiscale observing system simulation experiments for iron fertilization in the Southern Ocean, Equatorial Pacific, and Northeast Pacific. Period of performance: 9/1/2023 to 8/31/2026. Lead PI: Dennis McGillicuddy (Woods Hole Oceanographic Institution); Co-PIs: Ken Buesseler (WHOI), Gordon Zhang (WHOI), Matthew Long (NCAR), Kristen Krumhardt (NCAR), John Dunne (GFDL), Charles Stock (GFDL). Amount awarded to NCAR: $554,619

• NOAA, mCDR 2023: Biotic calcification impacts on marine carbon dioxide removal additionality. Period of performance: 9/1/2023 to 8/31/2027. Lead-PI: Kelly Kearney (Univ. of Washington); Co-PIs: Brenden Carter (Univ. of Washington), Darren Pilcher (Univ. of Washington), Kristen Krumhardt (NCAR). Amount awarded to NCAR: $291,343

CV_KKrumhardt.pdf

Links

Kristen's scientific illustration website

Full publication list on Google scholar

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