Toby Ault
Associate Professor and Director of Graduate Studies for Atmospheric Sciences, Earth and Atmospheric Sciences

Biography
Ault received his PhD from the University of Arizona in 2011, then completed an ASP postdoctoral fellowship at the National Center for Atmospheric Research from 2011-2013 before joining Cornell as an assistant professor.
Research Interests
Dr. Ault's research coalesces around three areas of inquiry related to emergent climate risks: (1) estimating the risk of prolonged drought under climate change; (2) understanding the dynamics of seasonality, particularly spring; and (3) characterizing variations in the Tropical Pacific on timescales of decades to centuries, and their influence on global climate. His methods entail data synthesis from observational sources as well as numerical and statistical modeling. The nature of his work is therefore highly interdisciplinary, affording him the opportunity to collaborate closely not only with climate scientists and modelers, but with colleagues in many other disciplines, including geography, paleoclimatology, and ecology.
Interests
Variations in tropical weather and climate
21st-century megadrought risk in the American Southwest
Energy and climate change
Recent Research
- Ault, T. R. and St. George, S (2018): Unraveling the mysteries of megadrought. Physics Today (Cover) 71, 8, 44 (2018); https://doi.org/10.1063/PT.3.3997.
- Ault, T. R., St. George, S., Smerdon, J. E., Coats, S., Mankin, J. S., Carrillo, C. M., Cook, B. I., Stevenson, S. (2018): A robust null hypothesis for the potential causes of megadrought in western North America. Journal of Climate, 31, 3–24, doi:10.1175/JCLI-D-17-0154.1.
- Ault, T. R. (2017): Reconciling disparate views on decadal climate variability from proxies and models, PAGES Magazine, vol. 25(1), 68-70, doi:10.22498/pages.25.1.68.
- Ault, Toby R. 2016. "Water resources: Island water stress." Nature Climate Change 6 (12): 1062-1063.
- Ault, Toby R., Justin S. Mankin, Benjamin I. Cook, Jason E Smerdon. 2016. "Relative impacts of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest." Science Advances 2 (10): e1600873.
- Monahan, William B., Alyssa Rosemartin, Katharine L. Gerst, Nicholas A. Fisichelli, Toby R. Ault, Mark D. Schwartz, John E. Gross, Jake F. Weltzin. 2016. "Climate change is advancing spring onset across the US national park system." Ecosphere 7 (10): e01465.
- Ault, Toby R., Zachary Labe, Raul Zurita-Milla. 2016. "Identifying anomalously early spring onsets in the CESM large ensemble project." Climate Dynamics 1-18.
- Newman, Matthew, Michael A. Alexander, Toby R. Ault, Kim M. Cobb, Clara Deser, Emanuele Di Lorenzo, Nathan J. Mantua, Arthur J. Miller, Hisashi Nakamura Shoshiro Minobe, Niklas Schneider, Daniel J. Vimont, Adam S. Phillips, James D. Scott, Catherine A. Smith. 2016. "The Pacific decadal oscillation, revisited." Journal of comparative neurology (29): 4399-4427.
Awards & Honors
- Faculty Fellow in Community Engaged Learning (Cornell Office of Engagement Initiatives) 2019
Courses Taught
- EAS 1101: Climate and Energy: a 21st Century Earth Science Perspective
- EAS 3050: Climate Dynamics
- EAS 5051: Climate Dynamics
- EAS 4960: Internship Experience
Contact Information
2108 Snee Hall
Ithaca, NY 14853
toby.ault [at] cornell.edu
Additional Links
Toby in the news

News
The project aligns with Cornell Atkinson's core mission of supporting research that drives meaningful impact across public opinion, policy, and corporate practices.
- Cornell Atkinson
- Earth and Atmospheric Sciences
- Climate Change

News
On June 2, the Ithaca theater organization Civic Ensemble will premiere “Fertile Grounds,” a community-based play that invites the audience onto a fictional farming cooperative involving people of color to explore the relationship of grief...
- Agriculture
- Health + Nutrition