Climate Dynamics at Colorado State University

We are using conceptual energy balance models, climate models, observations, and data driven methods and models to study how the ocean influences atmospheric feedbacks on large scales and stores and redistributes heat. We are studying first-order controls on Earth’s climate evolution over the last and next few decades, the concept of climate forcings, deep time paleo climate, and internal variability.

Group members
  • Maria Rugenstein email, Since 2020, I am an assistant professor for climate dynamics at the Department of Atmospheric Scienceat 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. My group is funded by NASA (NIP), NSF (CLD and P2C2), NOAA (MAPP), and DoE. I am a lead author on the forth comming IPCC AR7 report for the chapter on scenarios and climate projections. I got recognized with Outstanding Early Career Awards by EGU (2024), AMS (2025), and CSU (2026).

  • Leif Fredericks, 2nd year PhD student
  • Olivia Lee, 1st year PhD student
  • Killian McSweeney, 1st year PhD student
  • Aspen Morgan, 2nd year Master's student
  • Senne Van Loon, Senior Scientist, website
  • Benjamin Johnson, PostDoc
  • Vanessa Skiba, visiting PostDoc from Alfred Wegner Institute
  • Levi Silvers, part time senior scientist, otherwise in Michael Bell's group
  • Former group members: Chiara Ventrucci (visiting PhD student from University of Bologna); Tristan Rendfrey (PostDoc); Eva Holtanova (visiting fulbright researcher, now at Charles University in Prag); Yiyu Zheng (PhD from CSU, website); Shreya Dhame (PostDoc at MPI); Dhyey Solanki (Master's from CSU, now researcher at the Indian Institute of Technology); Marc Alessi (PhD from CSU, now lecturer at Cornell and researcher at the Union of Concerned Scientists); Dirk Olonscheck (PostDoc at MPI); Kenneth Tam (undergraduate research assistant, now graduate student at Rutgers University)

Publications

Google scholar

  • Fredericks, Rugenstein, Thompson, Van Loon, Falasca, Basinski-Ferris, Ceppi, Wu, Bloch-Johnson, Alessi, Kang, 2026: Quantifying the radiative response to surface temperature variability: A critical comparison of current methods, J. climate link
  • Alessi, Connolly, Barnes, Rugenstein, 2025: Southern Hemisphere Surface Warming Drives Southwestern U.S. Precipitation According to AI-informed Climate Model Simulations, J. climate link
  • Fredericks, Thompson, Rugenstein, 2025: Estimating the Pattern Effect Using Regularized Linear Regression, J. climate link
  • Joensson, Rugenstein, Bender, McCoy, Eidhammer, 2025: Parametric Sensitivity of Hemispheric Albedo Symmetry Weakly Constrains Shortwave Cloud Radiative Feedbacks in the Community Atmosphere Model Version 6, GRL link
  • Van Loon, Rugenstein, and Barnes, 2025: Reanalysis-based Global Radiative Response to Sea Surface Temperature Patterns: Evaluating the Ai2 Climate Emulator, GRL link
  • Dhame, Olonscheck, Rugenstein, 2025: Higher-Resolution Climate Models Do Not Consistently Reproduce the Observed Tropical Pacific Warming Pattern, J. climate link
  • Van Loon, Rugenstein, and Barnes, 2025: Observation-based estimate of Earth's effective radiative forcing, PNAS link
  • Zheng, Rugenstein, and Alessi, 2025: The Relationship between the Southern Ocean and the Southeastern Subtropical Pacific in Unforced and Forced Climate Model Simulations, J. Climate link
  • Thompson, Rugenstein, Forster, Fredericks, 2025: An Observational Estimate of the Pattern Effect on Climate Sensitivity: The Importance of the Eastern Tropical Pacific and Land Areas, J. climate link
  • Rugenstein, Van Loon, Barnes, 2025: Convolutional Neural Networks trained on internal variability predict forced response by learning the pattern effect, GRL link
  • Davis, Thompson, Rugenstein, Birner, 2025: Links Between Internal Variability and Forced Climate Feedbacks: The Importance of Patterns of Temperature Variability and Change, GRL link
  • Liu, Li, Li, Rugenstein, Thomas, 2024: Contrasting fast and slow intertropical convergence zone migrations linked to delayed Southern Ocean warming, Nature Climate Change link
  • Alessi and Rugenstein, 2024: Potential Near-Term Wetting of the Southwestern United States if the Eastern and Central Pacific Cooling Trend Reverses, GRL link
  • Olonscheck and Rugenstein, 2024: Coupled climate models systematically underestimate radiation response to surface forcing, GRL link
  • Bloch-Johnson, Rugenstein, Alessi, and 10 others, 2024: The Green's Function Model Intercomparison Project (GFMIP) Protocol, JAMES link
  • 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, 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
  • Lee, Rugenstein, Rugenstein, Van Loon: Contextualizing SWUS Precipitation in Past and Future Mean Climates with Marine Heatwaves subm
  • Johnson and Rugenstein: A Land-Sea Contrast Pattern in Surface Temperature and Atmospheric Circulation Trends in Recent Decades subm
  • Johnson and Rugenstein: The large-scale pattern assiciated with southwest US precipitation variability and its decline from 1979-2024 subm
  • Van Loon and Rugenstein: Spatial Controls of Lower Tropospheric Stability link subm
  • Van Loon, Rugenstein, Zelinka, Andrews: Recent Weakening of the Global Radiative Feedback link in revision GRL
  • McSweeney and Rugenstein: Revisiting the Southern Ocean Pattern Effect subm