Email: mleonte31@gmail.com

**LAB ALUMNUS**

RESEARCH INTERESTS

Methane has complex dynamics in ocean waters and sediments with numerous biogeochemical sources and sinks. Measurements of carbon and hydrogen isotopes of methane can distinguish how different sources and sinks are influencing methane distributions. Conventional techniques for these measurements are often slow and labor intensive causing many previous investigations to be data limited. My research focus is on building a Cavity Ring-Down Spectrometer (CRDS) capable of rapidly measuring the carbon and hydrogen isotopes of methane with very high sensitivity and precision in-situ. This field portable instrument will massively increase the rate of data collection and allow for high resolution measurements of methane concentrations and isotopes.

EDUCATION

• 2012-2019, Ph.D. Graduate Student, Dept of Earth & Environmental Sciences, University of Rochester, Rochester, NY.
• 2011, B.S. Chemistry & Earth System Science, University of California, Irvine
• Senior thesis title: Measuring the 34/32S ratio in atmospheric OCS using Gas Chromatography/Mass Spectroscopy

PROFESSIONAL EXPERIENCE

• September 2010 – July 2012, Research Assistant, Department of Earth System Science, University of California, Irvine, Saltzman Group

PUBLICATIONS

• Leonte, M., Ruppel, C. D., Ruiz-Angulo, A., and J. D. Kessler (2020). Surface methane concentrations along the Mid‐Atlantic Bight driven by aerobic subsurface production rather than seafloor gas seeps. Journal of Geophysical Research: Oceans. 125, e2019JC015989. https://doi.org/10.1029/2019JC015989 
• Joung, D.-J., M. Leonte, and J. D. Kessler (2019). Methane sources in the waters of Lake Michigan and Lake Superior as revealed by natural radiocarbon measurements. Geophysical Research Letters, 46, 5436–5444. https://doi.org/10.1029/2019GL082531
• Leonte, M.,  B. Wang,  S. A. Socolofsky,  S. Mau,  J. A. Breier, and  J. D. Kessler (2018). Using Carbon Isotope Fractionation to Constrain the Extent of Methane Dissolution Into the Water Column Surrounding a Natural Hydrocarbon Gas Seep in the Northern Gulf of Mexico. Geochemistry, Geophysics, Geosystems, 19, 4459–4475. https://doi.org/10.1029/2018GC007705
• Leonte, M., J. D. Kessler, M. Y. Kellermann, E. C. Arrington, D. L. Valentine, S. P. Sylva (2017), “Rapid rates of aerobic methane oxidation at the feather edge of gas hydrate stability in the waters of Hudson Canyon, US Atlantic Margin.” Geochimica et Cosmochimica Acta, 204, 375-387. https://doi.org/10.1016/j.gca.2017.01.009
• Weinstein, A., L. Navarrete, C. Ruppel, T. C. Weber, M. Leonte, M. Y. Kellermann, E. C. Arrington, D. L. Valentine, M. I. Scranton, and J. D. Kessler (2016), Determining the flux of methane into Hudson Canyon at the edge of methane clathrate hydrate stability, Geochem. Geophys. Geosyst., 17(10), 3882-3892. https://doi.org/10.1002/2016GC006421

TEACHING EXPERIENCE

• Fall 2012, Teacher’s Assistant, Hydrology 
• Spring 2013, Teacher’s Assistant, Chemical Oceanography
• Fall 2013, Teacher’s Assistant, Chemical Oceanography
• Spring 2013, Teacher’s Assistant, Introduction to Environmental Science
• Spring 2017, Teacher's Assistant, Marine Ecosystems & Carbon Cycle Modeling

FIELD EXPERIENCE

• 2019, May 26 - June 9, R/V Rachel Carson, US Pacific Margin, USA
• 2017, August 24 - September 7, R/V Hugh Sharp, US Atlantic Margin, USA
• 2017, June 13-22, R/V Blue Heron, Lake Superior and Michigan, USA
• 2016, June 21-24, R/V Blue Heron, Lake Michigan, USA
• 2016, May 1 - 9, R/V Helmer Hanssen, Longyeabyen, Svalbard, Norway
• 2015, April 8-21, E/V Nautilus, Gulf of Mexico, USA
• 2014, July 7-14, R/V Endeavor, North Atlantic Bight, USA
• 2012, August 7-14, R/V Cape Hatteras, Gulf of Mexico, USA

PRESENTATIONS

• 2018, Mihai Leonte, J. D. Kessler, C. D. Ruppel, and D.-J. Joung, Determination of Methane Sources and Sinks Using Stable Isotopes in Areas of Active Gas Seepage, AGU General Meeting, Washington D.C. (Poster)
• 2018, Mihai Leonte, J. D. Kessler, C. D. Ruppel, and D.-J. Joung, Determination of Methane Sources and Sinks Using Stable Isotopes in Areas of Active Gas Seepage, Ocean Carbon & Biogeochemistry (OCB): Oceanic Methane & Nitrous Oxide Workshop, Lake Arrowhead, CA. (Poster)
• 2018, Mihai Leonte, B. Wang, S. A. Scolofsky, and J. D. Kessler, Determination of Methane Sources and Sinks Using Stable Isotopes in Areas of Active Gas Seepage,  Gordon Research Conference on Natural Gas Hydrate Systems, Galveston, TX. (Poster)
• 2016, Mihai Leonte, J. Kessler, S. Scolofsky, Investigating the emission, dissolution, and oxidation of CH4 within and around a seep bubble plume in the Gulf of Mexico, Ocean Sciences, New Orleans, LA. (Poster)
• 2014, Leonte, M., J. Kessler, A. Chepigin, T. Weber, C. Ruppel, M. Kellermann, E. Arrington, D. Valentine, S. Silva. Comparison of Two Techniques to Calculate Methane Oxidation rates in Samples Obtained From the Hudson Canyon Seep Field in the North Atlantic . AGU General Meeting, San Francisco, CA. (Poster)

Current Member: No

Order Number: 5