Research interests lie in the general field of aqueous geochemistry and center on: 1) the transport of water and dissolved material in groundwater, surface waters, and the coastal ocean; 2) how flow patterns affect water quality; 3) gas exchange across the air-water interface; 4) climate change during the last 30,000 years. These questions are examined using experiments conducted by introducing chemical tracers into the water bodies, plus analysis of flow patterns, residence times, and mixing rates inferred from the distribution of natural and anthropogenic tracers.
• Impact of natural marine hydrocarbon seeps on the regional environment and global methane cycle. For more on seeps, surf to the Seeps website.
• Groundwater flow near Aquifer Storage and Recovery sites.
• Chemical evolution of the shallow groundwater.
Stieglitz, T. C., J. F. Clark, and G. Hancock (2013) The Mangrove Pump: rapid tidal Flushing of Animal Burrows in Mangrove Forests, a major driver of Land-Ocean Solute Fluxes in the Tropics. Geochimica et Cosmochimica Acta, 102, 12-22, doi.org/10.1016/j.gca.2012.10.033.
Manning, A. H., J. F. Clark, S. H. Diaz*, L. K. Rademacher, S. Earman, L. N Plummer (2012) Evolution of groundwater age in a mountain watershed over a period of thirteen years. Journal of Hydrology, 460, 13-28, doi:10.1016/j.jhydrol.2012.06.030.
Fisher, A. T., J. Cowen, C. G. Wheat, and J. F. Clark (2011), Preparation and injection of fluid tracers during IODP Expedition 327, eastern flank of Juan de Fuca Ridge in Proc. IODP 327, edited by A. T. Fisher, T. Tsuji and K. Petronotis. doi:10.2204/iodp.proc.327.108.2011, Integrated Ocean Drilling Program Management International, Inc., Tokyo.
Kline*, K. R., D. M. Mackay, L. Rastegarzadeh*, Y. M. Nelson, J. F. Clark (2011) In-Situ Rates of Ethanol Biodegradation in a Sulfate-Reducing Aquifer Determined using Single Well Push-Pull Tests.Ground Water Monitoring and Remediation, 31, 103-110 doi:10.1111/j1745-6592.2011.01347.x.
Morrissey*, S. K., J. F. Clark, M Bennett, E. Richardson, and M. Stute (2010) Groundwater reorganization in the Floridan aquifer following Holocene sea-level rise. Nature Geoscience, 3, 683-687, doi:10.1038/NGEO956.
Clark, J. F., L. Washburn, and K. Schwager* (2010) Variability of gas composition and flux intensity in natural marine hydrocarbon seeps. Geo-Marine Letters, 30, 379-388, doi:10.1007/s00367-009-0167-1.
MacIntyre, S., J. F. Clark, R. Jellison (2009) Turbulent mixing induced by nonlinear waves in Mono Lake. Limnology and Oceanography, 54, 2255-2272.
Rueda, F. J, S. G. Schladow and J. F. Clark (2008) Mechanisms of contaminant transport in a multi-basin lake. Ecological Applications. 18 Supplement, A72-A87.
Schladow, S. G. and J. F. Clark (2008) Use of Tracers to Quantify Subsurface Flow Through a Mining Pit. Ecological Applications, 18 Supplement, A55-A71.
Schmieder*, P. J., D. T. Ho, P. Schlosser, J. F. Clark, and S. G. Schladow (2008) An SF6 tracer study of the flow dynamics in the Stockton Deep Water Ship Channel: Implications for dissolved oxygen dynamics. Estuaries and Coasts, 31, 1038-1051, doi:10.1007/s12237-008-9093-0.
Meillier*, L. H. Loáiciga, and J. F. Clark (2008) Ground water dating and flow-model calibration in the Kern Water Bank, California. Journal of Hydrologic Engineering, ASCE, 13, 1029-1038.
McDermott*, J. A., D. Avisar, T. Johnson, and J. F. Clark (2008) Groundwater travel times near spreading ponds: Inferences from geochemical and physical approaches. Journal of Hydrologic Engineering, ASCE, 13, 1021-1028.
Blumhagen*, E. D. and J. F. Clark (2008) Carbon sources and signals through time in an alpine groundwater basin, Sagehen California. Applied Geochemistry, 23, 2284-2291, doi:10.1016/j.apgeochem.2008.03.010.
Duffy*, M., F. S. Kinnaman*, D. L. Valentine, E. A. Keller, and J. F. Clark (2007) Gaseous Hydrocarbon Fluxes from Natural Seeps in the Upper Ojai Valley, CA. Environmental Geosciences, 14, 197-207.
Mau, S., D. L. Valentine, J. F. Clark, J. Reed, R. Camilli, and L. Washburn (2007) Dissolved methane distributions and air-sea flux in the plume of a massive seep field, Coal Oil Point, California.Geophysical Research Letter, 34, L22603, doi:10.1029/2007GL031344.
Clark, J. F. (2007) Tracing Recharge Water from Spreading Ponds: A Decade of Studies. In:Management of Aquifer Recharge for Sustainability, ed. Fox, P., Acacia, Phoenix, p. 285-295.
Clark, J. F. and T. Stieglitz (2007) 2.2.2 Isotope and Tracer Techniques. In: Submarine Groundwater, ed. Zektser, I., L. G. Everett, and R. G. Dzhamalov, CRC Press, p. 110-117.
Clark, J. F. and G. B. Hudson (2006) Excess air: A new tracer for artificially recharged surface water. In: Recharge Systems for Protecting and Enhancing Groundwater Resources, IHP-VI, Series on Groundwater No. 13, UNESCO, 342-347.
Leifer, I., B. P. Luyendyk, J. R. Boles, J. F. Clark (2006) Natural marine seepage blowout: Contribution to atmospheric methane. Global Biogeochemical Cycles, 20, GB3008 10.1029/2005GB002668.
Cook, P. G., S. Lamontagne, D. Berhane, J. F. Clark (2006) Quantifying groundwater discharge to Cockburn River, southeastern Australia, using dissolved gas tracers 222Rn and SF6. Water Resources Research, 42, W10411, doi:10.1029/2006WR004921.
Clark, J. F., G. B. Hudson, and D. Avisar (2005) Gas transport below artificial recharge ponds: Insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment. Environmental Science and Technology, 39, 3939-3945.
Env Studies/Earth 168 Aqueous Transport
Env Studies/Earth 169/269 racer Hydrology
Earth 124 IG Introduction to Geochemistry
INT 84 Drinking Water for the 21st Century (Honors/freshman Seminar)
INT 94QE Mono Lake, Owens Valley and LA's Water Supply
(Freshman Seminar as a 3 days field trip)
Env Studies 192CC Chemistry of Global Change