Continental margins are shallow water regions of the ocean where a variety of methane sources are found. A supersaturation of methane in oceanic surface waters has been widely observed, but the source responsible for this supersaturation, which results in the sea-to-air flux of methane, can be variable over space and time. Determining the dominant source of methane to continental margin surface waters is the central focus of my graduate research. Radiocarbon methane measurements from surface waters will be my primary tool, but stable methane isotope measurements from the water column will also be made in order to tell a more complete story of the methane dynamics at work.


  • 2012-2017, Ph.D. Graduate Student, Dept of Earth & Environmental Sciences, University of Rochester, Rochester, NY.
  • 2011-2012, Ph.D. Graduate Student, Dept of Oceanography, Texas A&M University, College Station, TX.
  • 2011, B.S., Environmental Science, University of North Carolina at Wilmington, Wilmington, NC.


  • K. J. Sparrow, J. D. Kessler, J. R. Southon, F. Garcia-Tigreros, K. M. Schreiner, C. D. Ruppel, J. B. Miller, S. J. Lehman, X. Xu, Limited contribution of ancient methane to surface waters of the U.S. Beaufort Sea shelf. Science Advances 4, eaao4842 (2018).
  • K. J. Sparrow and J. D. Kessler (2017) "Efficient collection and preparation of methane from low concentration waters for natural abundance radiocarbon analysis." Limnology & Oceanography: Methods, doi: 10.1002/lom3.10184.
  • Garcia-Tigreros Kodovska, F., K.J. Sparrow, S.A. Yvon-Lewis, A. Paytan, N.T. Dimova, A. Lecher, J.D. Kessler. (2016) “Dissolved methane and carbon dioxide fluxes in Subarctic and Arctic regions: Assessing measurement techniques and spatial gradients.” Earth and Planetary Science Letters, doi: 10.1016/j.epsl.2015.12.002.
  • Dimova, N.T., A. Paytan, J.D. Kessler, K.J. Sparrow, F. Garcia-Tigreros Kodovska, A.L. Lecher, J. Murray, and S.M. Tulaczyk. (2015) "Current Magnitude and Mechanisms of Groundwater Discharge in the Arctic: Case Study from Alaska." Environmental Science & Technology, doi: 10.1021/acs.est.5b02215.
  • Lecher, A.L., J.D. Kessler, K. Sparrow, F. Garcia-Tigreros Kodovska, N. Dimova, J. Murray, S. Tulaczyk, A. Paytan. (2015) “Methane transport through submarine groundwater discharge to the North Pacific and Arctic Ocean at two Alaskan sites.” Limnology and Oceanography, doi: 10.1002/lno.10118.
  • Paytan, A., A. Lecher, N. Dimova, K. Sparrow, F. Garcia-Tigreros Kodovska, J.D. Kessler. (2015) “Methane transport from the active layer to lakes in the Arctic using Toolik Lake, Alaska, as a case study.” Proceedings of the National Academy of Sciences, doi:10.1073/pnas.1417392112.


  • 2015, Sparrow, K. and J. Kessler. Efficient Collection and Preparation of Methane from Extremely Large Volumes of Water for Natural Radiocarbon Analysis. 22nd International Radiocarbon Conference, Dakar, Sénégal. (Talk)
  • 2014, Sparrow, K. and J. Kessler. Efficient Collection of Methane from Extremely Large Volumes of Water for Natural Radiocarbon Analysis. AGU General Meeting, San Francisco, CA. (Poster)


  • 2015, August 28 - September 5, R/V Ukpik, Prudhoe Bay, Alaska, USA 
  • 2014, July 7-14, R/V Endeavor, North Atlantic Bight, USA
  • 2012, August 7-14, R/V Cape Hatteras, Gulf of Mexico, USA
  • 2012, July 29 - August 3, Barrow Field Station, Barrow, Alaska, USA
  • 2012, July 24 - 28, Toolik Field Station, Toolik Lake, Alaska, USA
  • 2012, July 19 - 23, Kasitsna Bay Laboratory, Kasitsna Bay, Alaska, USA
  • 2011, August 21 - 28, Kasitsna Bay Laboratory, Kasitsna Bay, Alaska, USA
  • 2011, August 13 - 20, Toolik Field Station, Toolik Lake, Alaska, USA
  • 2011, August 8 - 12, R/V Ukpik, Prudhoe Bay, Alaska, USA


  • Teacher’s Assistant, Spring 2013, Stable Isotope Geochemistry: Fractionation Equations and Models (EES 261/461)
  • Environmental Education Intern, Summer 2010, Chincoteague Bay Field Station of the Marine Science Consortium, Wallops Island, Virginia 


Current Member: No

Order Number: 2