Climate Dynamics at Colorado State University

We are using conceptual energy balance models, climate models of low and high resolution, and observations to study how the ocean influences atmospheric feedbacks on large scales and stores and redistributes heat. We like thinking about first-order controls on Earth’s climate, the concept of climate forcings, deep time paleo climate, internal variability, and the theory and sociology of science.

Group members

  • Postdoc position available, please reach out!

  • Maria Rugenstein email, Since 2000, I am an assistant professor for climate dynamics at the Department of Atmospheric Science at Colorado State University in Fort Collins. I studied at ETH Zürich, completed my Master's research at Princeton University/GFDL, and dived into paleoclimate research for two years in Utrecht, before completing my PhD in Zürich with visits to Stanford University and the Carnegie Institute for Global Ecology and a PostDoc at MPI in Hamburg. I coordinated a model intercomparison of millennia long simulations of global coupled Atmosphere-Ocean Models, LongRunMIP, together with Jonah Bloch-Johnson, and initiated the Green's Function Model Intercomparison, lead by Jonah. Check out this US-clivar workshop on the pattern effect I chaired together with Cristi Proistosescu. My group is funded by NASA (NIP), NSF (CLD and P2C2), and NOAA (MAPP).

  • Marc Alessi, 4th year PhD student, website
  • Yiyu Zheng, 3rd year PhD student, website
  • Dhyey Solanki, 1st year PhD student
  • Leif Fredericks, 2nd year Master's student
  • Olivia Lee, 1st year Master's student
  • Killian McSweeney, 1st year Master's student
  • Senne Van Loon, PostDoc, website
  • Shreya Dhame, PostDoc at Max-Planck in Hamburg, website
  • Former group members: Dirk Olonscheck (now PostDoc at MPI); Kenneth Tam (now graduate student at Rutgers University)


Google scholar

  • Rugenstein, Dhame, Olonscheck, Wills, Watanabe, Seager, 2023 Connecting the SST pattern problem and the hot model problem, GRL link
  • Rugenstein, Zelinka, Karnauskas, Ceppi, Andrews, 2023 Patterns of Surface Warming Matter for Climate Sensitivity, EOS link
  • Alessi and Rugenstein, 2023 Relevance of the pattern effect for near-future climate projections, accepted in GRL link
  • Mitevski, Dong, Polvani, Rugenstein, Orbe, 2023: Non-monotonic feedback dependence on CO2 due to North Atlantic pattern effect, GRL link
  • Rugenstein and Hakuba, 2023: Connecting Hemispheric Asymmetries of Planetary Albedo and Surface Temperature, GRL link
  • Fredriksen, Smith, Modak, Rugenstein, 2023: 21st century scenario forcing increases more for CMIP6 than CMIP5 models, GRL link
  • Bloch-Johnson, Rugenstein, Gregory, Cael, Andrews, 2022: Climate impact assessments should not discount 'hot' models, Nature link
  • Sanderson and Rugenstein, 2022: Potential for bias in effective climate sensitivity from state-dependent energetic imbalance, Earth System Dynamics link
  • Zheng, Rugenstein, Pieper, Beobide-Arsuaga, Baehr, 2022: El Niño–Southern Oscillation (ENSO) predictability in equilibrated warmer climates, Earth System Dynamics link
  • Bonan, Thompson, Newsom, Sun, Rugenstein, 2022: Transient and Equilibrium Responses of the Atlantic Overturning Circulation to Warming in Coupled Climate Models: The Role of Temperature and Salinity, J. Climate link
  • Fredriksen, Rugenstein, Graversen, 2021: Estimating forcing with a nonconstant feedback parameter and linear response, JGR Atmospheres link
  • Rugenstein and Armour, 2021: Three flavors of radiative feedbacks and their implications for estimating Equilibrium Climate Sensitivity, GRL link pdf
  • Lu, He, Fuso, Rugenstein, 2021: Mechanisms of Fast Walker Circulation Responses to CO2 Forcing, GRL link pdf
  • King, and 9 others, 2021: Transient and quasi-equilibrium climate states at 1.5C and 2C global warming, Earth's Future link
  • Ricke, Ivanova, McKie, Rugenstein, 2021: Reversing Sahelian Droughts, GRL link pdf
  • Callahan, Chen, Rugenstein, Bloch-Johnson, Yang, Moyer, 2021: Robust decrease in ENSO amplitude under long-term warming, Nature Climate Change link
  • Schwarzwald, Poppick, Rugenstein, Bloch-Johnson, Wang, McInerney, Moyer, 2021: Changes in Future Precipitation Mean and Variability across Scales, J. Climate link
  • Bloch-Johnson, Rugenstein, Stolpe, Rohrschneider, Zheng, Gregory, 2020: Climate Sensitivity Increases Under Higher CO2 Levels Due to Feedback Temperature Dependence, GRL link
  • Sherwood, Webb and 22 others, 2020: A combined assessment of Earth's climate sensitivity, Rev. of Geophys. press coverage press coverage
  • Fiedler, and 24 others, 2020: Simulated Tropical Precipitation Assessed Across Three Major Phases of the Coupled Model Intercomparison Project (CMIP), MWR link
  • Olonscheck, Rugenstein, Marotzke, 2020: Broad consistency between observed and simulated trends in sea surface temperature patterns, GRL link pdf
  • Bloch-Johnson, Rugenstein, Abbot, 2020: Spatial radiative feedbacks from internal variability using multiple regression, J. Climate link pdf
  • Rugenstein, Bloch-Johnson, Gregory, and 13 others, 2020: Equilibrium climate sensitivity estimated by equilibrating climate models, GRL link pdf
  • Bellouin, Quaas, and 31 others, 2020: Bounding aerosol radiative forcing of climate, Rev. of Geophys. link pdf
  • Rugenstein, Bloch-Johnson, and 25 others, 2019: LongRunMIP - motivation and design for a large collection of millennial-length GCM simulations, BAMS link pdf
  • Praetorius, Rugenstein, Persad, Caldeira, 2018: Global and Arctic climate sensitivity enhanced by changes in North Pacific heat flux, Nature Comm. link pdf
  • Knutti, Rugenstein, Hegerl, 2017: Beyond climate sensitivity, Nature Geoscience link updated Figure
  • Rugenstein, Caldeira, Knutti, 2016: Dependence of global radiative feedbacks on evolving patterns of surface heat fluxes, GRL link pdf
  • He, Winton, Vecchi, Jia, Rugenstein, 2016: Transient Climate Sensitivity Depends on Base Climate Ocean Circulation, J. Climate link pdf
  • Rugenstein, Gregory, Schaller, Sedlacek, Knutti, 2016: Multi-annual ocean-atmosphere adjustments to radiative forcing, J. Climate link pdf
  • Rugenstein, Sedlacek, Knutti, 2016: Nonlinearities in patterns of long term ocean warming, GRL link pdf
  • Knutti and Rugenstein, 2015: Feedbacks, climate sensitivity and the limits of linear models, Phil. Trans. R. Soc. A link pdf
  • Rugenstein, Stocchi, von der Heydt, Dijkstra, Brinkhuis, 2014: Emplacement of Antarctic ice sheet mass affects circumpolar ocean flow, Global and Planetary Change link pdf
  • Rugenstein, Winton, Stouffer, Griffies, Hallberg, 2013: Northern high latitude heat budget decomposition and transient warming, J. Climate link pdf

Manuscripts in review or revision

  • Olonscheck and Rugenstein Coupled climate models systematically underestimate radiation response to surface forcing
  • Bloch-Johnson, Rugenstein, Alessi, Proistosescu,++ The Green's Function Model Intercomparison Project (GFMIP) Protocoll link
  • Liu, Li, Li, Rugenstein, Thomas, A swing of the inter-tropical convergence zone driven by delayed Southern Ocean warming and heat uptake reduction
  • King, Brown, Harrington, Perkins-Kirkpatrick, Rugenstein The recent climate in the context of of a Paris Agreement 1.5degree world


  • In 2022, Leif joined as a Master student; Kenny joined as an REU student for the summer and stayed as student researcher, and Shreya joined our exclave at MPI; Aiden Jönsson and Eirik Enger joined us for a few months as visitors; everybody presented at the pattern effect workshop; Marc presented at the ECS virtual symposium and the MPI in Hamburg where he spent three months as a Humboldt fellow; Yiyu presented at the ICTP summer school; Shreya and Dirk presented at Constrain meetings; Kenny, Yiyu and Maria presented at the AGU fall meeting; Maria gave talks at the University of Wyoming, the CERES science team annual meeting, the HiLAT-RASM webinar, the University of Edinburgh, the University of Lyon, Yale University, the University of Boulder, the Winton symposium, the AMS AOFD meeting, the University of Reading, and the AMS Madison Meeting.
  • In 2021, Yiyu joined as a PhD student and gave a talk at the Graduate Climate Conference; Marc, Dirk, and Maria presented at the AGU fall meeting and the CFMIP annual meeting; Maria gave talks at MIT, Caltech, the University of Oslo, the Libera science meeting, University of Bergen, and the Imperical College London and received the Editor's Citation for Excellence in Refereeing from GRL.
  • In 2020, Marc started as PhD student; Maria was elected for the NASA MPOWIR speaker series; Yiyu and Maria gave talks at the AGU fall meeting; Maria gave talks at CFMIP, the ECS virtual symposium, and the University of Leeds.