Sonny Harman

Affiliation: NASA Ames Research Center (ARC)

Division: Space Science and Astrobiology Division (ST)

Branch: Planetary Systems Branch (STT)

Email: sonny.harman@nasa.gov

Phone: 650-604-1671

Websites: MCMC Homepage | Exoplanet Research at Ames

Professional Biography

I study the atmospheric composition and evolution of low- to intermediate-mass planets using 1-D and 3-D numerical models. My research interests include making connections between the geologic record and the potential atmospheric state of the early Earth; estimating the interactions of a host star’s radiation with the dominant and trace gases in the atmospheres of Earth-like extrasolar planets; and predicting the disposition of warm super-Earths/sub-Neptunes that have lost some (or all) of their hydrogen. I also have a keen interest in innovative scientific data visualizations for a broader audience. I became interested in planetary science as an undergraduate student, ultimately choosing to pursue a graduate degree with Dr. James Kasting at Penn State. Following that, I worked with the ROCKE-3D global climate modeling group at NASA GISS, led by Dr. Anthony Del Genio, as a postdoctoral research scientist working on model development and terrestrial planet simulations. I then spent some time as a postdoctoral researcher at the University of St. Andrews working with Dr. Mark Claire on 1-D photochemical modeling of the sulfur cycle in the early Earth’s atmosphere before coming to NASA Ames in January of 2020.

Education

Ph.D. Geosciences/Astrobiology (Computational Science), Pennsylvania State University – 2017

M.S. Geosciences, Pennsylvania State University – 2013

B.S. Physics (Mathematics), Millersville University – 2010

Research Interests

Planetary atmospheres, atmospheric chemistry, rocky planets, terrestrial atmospheres, numerical modeling.

Select Publications

Krissansen-Totton, J., Ulses, A. G., Frissell, M., Gilbert-Janizek, S., Young, A., Lustig-Yaeger, J., Robinson, T., Olson, S., Alei, E., Arney, G., Hagee, C., Harman, C.E., … & Wogan, N. (2025). Wavelength Requirements for Life Detection via Reflected Light Spectroscopy of Rocky Exoplanets. https://arxiv.org/abs/2507.14771.

Scarsdale, N., Harman, C. E., & Fauchez, T. J. (2025). The Spin Zone: Synchronously and Asynchronously Rotating Land Planets Have Spectral Differences in Transmission. The Planetary Science Journal, 6(5), 120. doi:10.3847/PSJ/adcea9

Sohl, L. E., Fauchez, T. J., Domagal-Goldman, S., Christie, D. A., Deitrick, R., Haqq-Misra, J., Harman, C.E., … & Chaverot, G. (2024). The CUISINES Framework for Conducting Exoplanet Model Intercomparison Projects, Version 1.0. The Planetary Science Journal, 5(8), 175. doi:10.3847/PSJ/ad5830

Harman, S. (2023). The Search for Slow Sulfur Sinks. AGU Advances, 4. doi:10.1029/2023AV001064

Kahre, M.A., Haberle, R.M., Wilson, R.J., Urata, R.A., Steakley, K.E., Brecht, A.S., Bertrand, T., Kling, A.L.M., Batterson, C.M.L., Hartwick, V.L., Harman, C.E. & Gkouvelis, L. (2023). The NASA Ames legacy Mars global climate model: Radiation code error correction and new baseline water cycle simulation. Icarus, 400, 115561–115561. doi:10.1016/j.icarus.2023.115561

Diamond-Lowe, H., Kreidberg, L., Harman, C. E., Kempton, E. M. R., Rogers, L. A., Joyce, S. R., … & Crossfield, I. J. (2022). The K2-3 system revisited: Testing photoevaporation and core-powered mass loss with three small planets spanning the radius valley. The Astronomical Journal, 164(5), 172. doi:10.3847/1538-3881/ac7807

Harman, C. E., Kopparapu, R. K., Stefánsson, G., Lin, A. S., Mahadevan, S., Hedges, C., & Batalha, N. E. (2022). A snowball in hell: The potential steam atmosphere of TOI-1266c. The Planetary Science Journal, 3(2), 45. doi:10.3847/PSJ/ac38acHarman, C. E. (2021). The chemistry of extrasolar planets. Encyclopedia of Geology, Second Edition. doi:10.1016/B978-0-08-102908-4.00151-X

Technologies & Software

NASA Ames MCMC (2024, December 6). Ames Mars GCM (Version 3.2) [Computer software]. NASA GitHub. doi: 10.25966/ty4s-w176

NASA Ames MCMC (2024, January 17). Ames Mars GCM (Version 3.1) [Computer software]. NASA GitHub. doi: 10.25966/ty4s-w176

NASA Ames MCMC (2023, November 29). Ames Mars GCM (Version 3.0) [Computer software]. NASA GitHub. doi: 10.25966/ty4s-w176

NASA Ames MCMC (2025). Community Analysis Pipeline (Version 4.0) [Computer software]. NASA Planetary Science GitHub.

NASA Ames MCMC (2024, August 14). Data Portal Web Interface [Web tool]. NASA Ames Research Center, NASA.

NASA Ames MCMC (2023, April 12). NASA Ames Legacy Mars Global Climate Model [Computer software]. NASA GitHub. doi: 10.25966/3tpw-nt26

NASA Ames MCMC (2023). Beta Output Release 1 [Data set]. NASA Ames Mars Climate Modeling Center Data Portal. doi: 10.25966/rjgg-r639

NASA Ames MCMC (2023). Legacy Output Release [Data set]. NASA Ames Mars Climate Modeling Center Data Portal. doi: 10.25966/3tpw-nt26

Select Seminars & Conference Presentations

Brecht, A.S., Harman, C.E., Kahre, M.A., Urata, R.A., Wilson, R.J., Batterson, C.M.L., Gkouvelis, L. & Kling, A.L.M. (2025). Advancements in Vertically Extending the NASA Ames Mars Global Climate Model [Abstract]. Presented at the AGU Fall Meeting, New Orleans, LA.

Brecht, A.S., Harman, C.E., Gkouvelis, L., Wilson, R.J., Kling, A.L.M., Urata, R.A. & Kahre, M.A. (2024). Characterizing the Martian Mesosphere with the NASA Ames Mars Global Climate Model [Abstract]. LPI Contributions, 3007. Presented at the Tenth International Conference on Mars, Pasadena, CA.

Brecht, A.S., Harman, C.E., Leonardos, G., Wilson, R.J., Kling, A.L.M., Urata, R.A. & Kahre, M.A. (2024). Investigating the diurnal behavior of the Martian mesosphere with the NASA Ames Mars Global Climate Model [Abstract]. Presented at the AGU Fall Meeting, Washington, D.C.

Brecht, A.S., Gkouvelis, L., Harman, C.E., Wilson, R.J., Kling, A.L.M., Urata, R.A. & Kahre, M.A. (2023). Simulating the Martian Mesopause with the NASA Ames Mars Global Climate Model [Abstract]. Presented at the AGU Fall Meeting, San Francisco, CA.