Maria Prokopenko

My research is driven by questions of how the processes occurring in the ocean are shaped by interactions between the three major components of the Earth system: the bio-, hydro- and geo-spheres. I look to identify and characterize the links between biologically driven fluxes and physical processes in the oceans on a variety of spatial and temporal scales. I study the distribution of various biogeochemical tracers, such as nutrient concentrations and stoichiometries, dissolved gases (N2, O2 and Ar), as well as nitrogen (δ15N) and oxygen (δ18O and δ17O) isotope ratios. I apply this information to quantify the rates of the biogeochemical N, O and C cycling constructing simple geochemical models. The magnitude, as well as spatial and temporal dynamics of the biogeochemical fluxes is comparable to a chemical heartbeat of Earth’s ecosystems, and can be used to diagnose the influence of various environmental factors. Such information is crucial for our ability, as a society, to predict potential consequences of the ongoing rapid environmental change on marine ecosystems.

Papers (within last 6 years):

* denotes student author

Wang X.T.*, Sigman D.M., Prokopenko M.G., Adkins J.F., Robinson L.F., Hines* S.K., Chai J. Studer A.S., Martinez-Garcia A., Chen T. , Haug G.H. (2017) “Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age”

William Z. Haskell II*, Maria G. Prokopenko, Douglas E. Hammond, Rachel H. R. Stanley, Zoe O. Sandwith (2017) “Annual cyclicity in export efficiency in the inner Southern California Bight” DOI: 10.1002/2016GB005561

Haskell, W.Z.*, Prokopenko, M.G., Hammond, D.E., Stanley, R.H.R., Berelson, W.M., Baronas, J.J.*, Fleming, J.C. and Aluwihare, L.  (2016) “An organic carbon budget for coastal Southern California determined by estimates of vertical nutrient flux, net community production and export,” Deep Sea Research Part I: Oceanographic Research Papers, 116: 49-76.

Haskell, W.Z., Prokopenko, M.G., Stanley, R.H.R. and Knapp, A.N. (2016) “Estimates of vertical turbulent mixing used to determine a vertical gradient in net and gross oxygen production in the oligotrophic South Pacific Gyre,” Geophysical Research Letters, 43(14): 7590-7599

Angela N. Knapp, Karen L. Casciotti, William M. Berelson, Maria G. Prokopenko, and Douglas G. Capone (2016) “Low rates of nitrogen fixation in eastern tropical South Pacific surface waters,” Proceedings of the National Academy of Sciences, vol.113, n. 16, 4398-4404

Haskell, William, Z.*, Hammond, Douglas E., Prokopenko, Maria G. (2015) “A dual-tracer approach to estimate upwelling velocity in coastal Southern California,” Earth and Planetary Science Letters, 422, 138-149

Yeung, Laurence Y.; Berelson, William M.; Hammond, Douglas E.; Prokopenko, Maria G.; Wolfe, Christa*; Rollins, Nick (2015) “Upper-ocean gas dynamics for biogeochemical applications using radon profiles in the Eastern Tropical South Pacific,” Deep Sea Research Part I, vol. 99, pp. 35-45

Tems, Caitlin E.*, Berelson, William M., Prokopenko, Maria G. (2015) “δ¹⁵N in laminated marine sediments provide a proxy for mixing between the California Undercurrent and the California Current: A proof of concept,” Geophysical Research Letters, DOI: 10.1002/2014GL061993

Berelson, WM; Haskell II, WZ*; Prokopenko, M; Knapp, AN; Hammond, DE; Rollins, N; Capone, DG, (2015) “Biogenic particle flux and benthic remineralization in the Eastern Tropical South Pacific,” Deep Sea Research Part I: Oceanographic Research Papers, DOI:10.1016/j.dsr.2014.12.006

Haskell, William Z.II*, Kadko, David, Hammond, Douglas E., Knapp, Angela N., Prokopenko, Maria G., Berelson, William M., Capone, Douglas G. (2015) “Upwelling velocity and eddy diffusivity from 7Be measurements used to compare vertical nutrient flux to export POC flux in the Eastern Tropical South Pacific,” 2015, Marine Chemistry, 168, pp. 140-150

Townsend-Small, A., Prokopenko, M.G., Berelson W.M.  (2014), “Nitrous oxide cycling in the water column and sediments of the oxygen minimum zone, eastern subtropical North Pacific, Southern California, and Northern Mexico (23° N–34° N),” Journal of Geophysical Research: Oceans, 119 (5), pp.3158-3170

Morales, L.V.*; Granger, J.; Chang, B. X.; Prokopenko, M. G. ; Plessen, B.; Gradinger, R.; Sigman, D.M. (2014), “Elevated 15N/14N in particulate organic matter, zooplankton, and diatom frustule-bound nitrogen in the ice-covered water column of the Bering sea eastern shelf,” Deep Sea Research Part II: Topical Studies in Oceanography       

Wang, X. T.*; Prokopenko, M. G.; Sigman, D. M.; Adkins, J. F.; Robinson, L.F.; Ren, H.; Oleynik, S.; Williams, B.; Haug, G. H. (2014), “Isotopic composition of carbonate-bound organic nitrogen in deep-sea scleractinian corals: A new window into past biogeochemical change,” Earth and Planetary Science Letters, 400, 243-250

Prokopenko, M.G., M.B. Hirst*, L. De Brabandere, W.M. Berelson, D.J. Lawrence*, J. Granger, B. X. Chang, S. Dawson., E.J. Crane, L. Chong*, B. Thamdrup , A. Townsend-Small, D.M. Sigman (2013) “Syntrophy between anammox bacteria and Thioploca drives nitrogen losses in anoxic marine sediments,” Nature, v. 500, pp. 194-198, doi:10.1038/nature12365

Granger, J., Prokopenko, M.G., Mordy, C.W. and Sigman, D.M. (2013) “The proportion of remineralized nitrate on the ice-covered eastern Bering Sea shelf evidenced from the oxygen isotope ratio of nitrate,” Global Biogeochemical Cycles, 27(3), pp. 962-971.

*Chong, L., Prokopenko, M.G., Berelson, W.M., Townsend-Small, A., McManus, J. (2012) “Nitrogen cycling within suboxic and anoxic marine sediments from the continental margin of Western North America,” Marine Chemistry, v. 128, pp. 13-25, doi:10.1016/j.marchem.2011.10.007

Yeung, L.Y., W. M. Berelson, E. D. Young, M.G. Prokopenko,  N. Rollins, V.J. Coles, J. P. Montoya,  E. J. Carpenter, and P. L. Yager (2012) “Impact of diatom-diazotroph associations on carbon export in the Amazon River plume,” Geophysical Research Letters, 39, 6, doi: L18609 10.1029/2012gl053356

Sañudo-Wilhelmy S.A., L. Cutter, R. Durazo, E. Smail*, L. Gomez-Consarnau, E. A. Webb, M. Prokopenko, D.M. Karl and W. M. Berelson (2012) “Multiple B-vitamin deficiency in large areas of the coastal ocean,”,PNAS, doi:10.1073/pnas.1208755109

Ren, H., Sigman, D.M., Thunnel, R.C., Prokopenko, M.G., “Nitrogen isotopic composition of planktonic foraminifera from the modern and recent sediments,” (2012) Limnology and Oceanography, 57(4), 1011-1024, doi: 10.4319/lo.2012.57.4.1011

Silver, Bianca J.*, Raymond, R., Sigman, D.,  Prokopenko, M.,  Sherwood Lollar, B.,  Lacrampe-Couloume, G.,  Fogel, M., Pratt, L., Lefticariu, L., Onstott, T. (2012) “The origin of NO3- and N2 in deep subsurface fracture water of South Africa,” Chemical Geology, v. 294-295, pp. 51-62, doi:10.1016/j.chemgeo.2011.11.01

Prokopenko, M.G., Sigman, D.M., Berelson, W.M., Hammond, D.E., Barnett, B., Chong, L*, Townsend-Small, A. (2011) “Denitrification in anoxic sediments supported by biological nitrate transport,” Geochimica et Cosmochimica Acta, doi:10.1016/j.gca.2011.09.023

Prokopenko, M.G., Pauluis, O. M., Granger, J., Yeung, L. Y. (2011) “Exact evaluation of gross photosynthetic production from the oxygen triple-isotope composition of O2: Implications for the net-to-gross primary production ratios,” Geophys. Res. Letters, 38, doi:10.1029/2011GL047652

Granger, J., Prokopenko, M.G., Sigman, D. , Mordy C., Morse, Z., Morales, L*., Sambrotto, R., Plessen B. (2011) “Nitrification-coupled denitrification in sediment of the eastern Bering Sea shelf leads to 15N-enrichment of fixed N in shelf waters,”  Journal of Geophysical Research –Oceans, doi:10.1029/2010JC006751