Samar Khatiwala
111 Comer Geochemistry Building
Lamont Doherty Earth Observatory
Columbia University
Palisades, NY 10964

Email: spk@ldeo.columbia.edu
Phone: 845-365-8454
Fax: 845-365-8155


Curriculum Vitae

CV (4/1/2012)

Publications

  • H. D. Graven, N. Gruber, R. Key, S. Khatiwala, and X. Giraud. Changing controls on oceanic radiocarbon: New insights on shallow-to-deep ocean exchange and anthropogenic co uptake. J. Geophys. Res. (in revision), 2012.
  • S. Khatiwala, F. Primeau, and M. Holzer. Ventilation of the deep ocean constrained with tracer observations and implications for radiocarbon estimates of ideal mean age. Earth and Planet. Sci. Lett., doi: 10.1016/j.epsl.2012.01.038, 2012. (PDF)
  • S. Khatiwala, T. Tanhua, S. Mikaloff Fletcher, M. Gerber, S. C. Doney, H. D. Graven, N. Gruber, G. A. McKinley, A. Murata, A. F. Ríos, C. L. Sabine, and J. L Sarmientor. Global ocean storage of anthropogenic carbon. Biogeoscience (submitted), 2012.
  • I. Kriest, A. Oschlies, and S. Khatiwala. Sensitivity analysis of simple global marine biogeochemical models. Glob. Biogeochem. Cy., doi: 10.1029/2011GB004072, 2012. (PDF)
  • C. L. Sabine, R. A. Feely, R. Wanninkhof, T. Takahashi, S. Khatiwala, and G.-H. Park. The global ocean carbon cycle [in ``State of the Climate in 2011'']. BAMS (submitted), 2012.
  • D. Wang, S. Khatiwala, and M. A. Cane. Present and future source regions and transit time distributions of Pacific equatorial thermocline waters. JGR (submitted), 2012.
  • S. Wang, J. K. Moore, F. Primeau, and S. Khatiwala. Simulation of anthropogenic CO2 uptake in the CCSM3.1 ocean circulation-biogeochemical model: comparison with data-based estimates. Biogeosciences, 9:1321–1336, 2012. (PDF)
  • D. P. Nicholson, S. R. Emerson, S. Khatiwala, and R. C. Hamme. An inverse approach to estimate bubble-mediated air-sea gas flux from inert gas measurements. In S. Komori, W. McGillis, and R. Kurose, editors, The 6th International Symposium on Gas Transfer at Water Surfaces, pages 223–237. Kyoto University Press, 2011. (PDF)
  • C. L. Sabine, R. A. Feely, R. Wanninkhof, T. Takahashi, S. Khatiwala, and G.-H. Park. The global ocean carbon cycle [in ``State of the Climate in 2010'']. Bull. Amer. Meteor. Soc., 92 (6):S100–S105, 2011. (PDF)
  • C. A. Carlson, D. A. Hansell, N. B. Nelson, D. A. Siegel, W. M. Smethie, S. Khatiwala, M. M. Meyers, and E. Halewood. Dissolved organic carbon export and subsequent remineralization in the mesopelagic and bathypelagic realms of the North Atlantic basin. Deep-Sea Res. II, 57 (doi:10.1016/j.dsr2.2010.02.013), 2010. (PDF)
  • M. Holzer, F. Primeau, W. Smethie, and S. Khatiwala. Where and how long ago was water in the western North Atlantic ventilated? Maximum-entropy inversions of bottle data from WOCE line A20. J. Geophys. Res., 115 (doi:10.1029/2009JC005750), 2010. (PDF)
  • I. Kriest, S. Khatiwala, and A. Oschlies. Towards an assessment of simple global marine biogeochemical models of different complexity. Prog. Oceanogr., 86 (doi:10.1016/j.pocean.2010.05.002), 2010. (PDF)
  • C. L. Sabine, R. A. Feely, R. Wanninkhof, T. Takahashi, S. Khatiwala, and G.-H. Park. The global ocean carbon cycle [in ``State of the Climate in 2009'']. Bull. Amer. Meteor. Soc., 91 (6):S71–S75, 2010. (PDF)
  • S. Khatiwala, F. Primeau, and T. Hall. Reconstruction of the history of anthropogenic CO2 concentrations in the ocean. Nature, 462 (doi: 10.1038/nature08526), 2009. (link; supplementary material: link; see also related 'Making the Paper' story in the same issue: link.) See also the Columbia press release, and media coverage in The New York Times, TIME magazine, National Geographic magazine, NPR, VOA, and German public radio.
  • K. Jones, S. Khatiwala, T. van de Flierdt, S. Hemming, and S. Goldstein. Modeling the distribution of Nd isotopes in the oceans using an ocean general circulation model. Earth and Planet. Sci. Lett., 272:610–619, 2008. (PDF)
  • S. Khatiwala. Fast spin up of ocean biogeochemical models using matrix-free Newton-Krylov. Ocean Modell., 23:121–129, 2008. (PDF)
  • T. Merlis and S. Khatiwala. Fast dynamical spin-up of ocean general circulation models using Newton-Krylov methods. Ocean Modell., 21:97–105, 2008. (PDF)
  • M. Siddall, S. Khatiwala, T. van de Flierdt, K. Jones, S. Goldstein, S. Hemming, and R. F. Anderson. Towards explaining the Nd paradox using reversible scavenging in an ocean general circulation model. Earth and Planet. Sci. Lett., 274:448–461, 2008. (PDF)
  • S. Khatiwala. A computational framework for simulation of biogeochemical tracers in the ocean. Glob. Biogeochem. Cy., 21 (doi: 10.1029/2007GB002923), 2007. (PDF)
  • N. B. Nelson, D. A Siegel, C. A. Carlson, C. Swan, W. M. Smethie, and S. Khatiwala. Hydrography of chromophoric dissolved organic matter in the North Atlantic. Deep Sea Res. I, 54:710–731, 2007. (PDF)
  • F. Terenzi, T. M. Hall, S. Khatiwala, C. B. Rodehacke, and D. A. LeBel. Uptake of natural and anthropogenic carbon by the Labrador Sea. Geophys. Res. Lett., 34 (doi: 10.1029/2006GL028543), 2007. (PDF)
  • S. Khatiwala, M. Visbeck, and M. Cane. Accelerated simulation of passive tracers in ocean circulation models. Ocean Modell., 9:51–69, 2005. (PDF)
  • T. M. Hall, D. W. Waugh, T. W. N. Haine, P. E. Robbins, and S. Khatiwala. Estimates of anthropogenic carbon in the Indian Ocean with allowance for mixing and time-varying air-sea CO2 disequilibrium. Glob. Biogeochem. Cy., 18 (doi: 10.1029/2003GB002120), 2004. (PDF)
  • S. Khatiwala. Generation of internal tides in an ocean of finite depth: analytical and numerical calculations. Deep-Sea Res. I, 50:3–21, 2003. (PDF)
  • S. Khatiwala, P. Schlosser, and M. Visbeck. Rates and mechanisms of water mass transformation in the Labrador Sea as inferred from tracer observations. J. Phys. Oceanogr., 32:666–686, 2002. (PDF)
  • P. Schlosser, B. Ekwurzel, S. Khatiwala, R. Newton, W. Maslowski, and S. Pfirman. Correction to ``Decrease of river runoff in the upper waters of the Eurasian Basin, Arctic Ocean, between 1991 and 1996: Evidence from δ18O data''. Geophys. Res. Lett., 29 (doi:10.1029/2002GL015698), 2002. (PDF)
  • P. Schlosser, R. Newton, B. Ekwurzel, S. Khatiwala, R. Mortlock, and R. Fairbanks. Decrease of river runoff in the upper waters of the Eurasian Basin, Arctic Ocean, between 1991 and 1996: Evidence from δ18O data. Geophys. Res. Lett., 29 (doi: 10.1029/2001GL013135), 2002. (PDF)
  • N. Schörghofer, O. Aharonson, and S. Khatiwala. Slope streaks on Mars: Correlations with surface properties and the potential role of water. Geophys. Res. Lett., 29 (doi: 10.1029/2002GL015889), 2002. (PDF)
  • S. Khatiwala, B. E. Shaw, and M. A. Cane. Enhanced sensitivity of persistent events to weak forcing in dynamical and stochastic systems: Implications for climate change. Geophys. Res. Lett., 28:2633–2636, 2001. (PDF)
  • S. Khatiwala, M. Visbeck, and P. Schlosser. Age tracers in an ocean GCM. Deep-Sea Res. I, 48:1423–1441, 2001. (PDF)
  • S. Khatiwala and M. Visbeck. An estimate of the eddy-induced circulation in the Labrador Sea. Geophys. Res. Lett., 27:2277–2280, 2000. (PDF)
  • P. Schlosser, B. Ekwurzel, S. Khatiwala, R. Newton, W. Maslowski, and S. Pfirman. Tracer studies of the Arctic freshwater budget. In E. L. Lewis, editor, Freshwater balance of the Arctic Ocean, NATO Science Series, pages 453–478. Kluwer Academic Publishers, 2000.
  • S. Khatiwala, R. G. Fairbanks, and R. Houghton. Freshwater sources to the coastal ocean off northeastern North America: Evidence from H218O/H216O. J. Geophys. Res., 104:18241–18255, 1999. (PDF)
  • P. Schlosser, R. Bayer, G. Bonisch, L. Cooper, B. Ekwurzel, W. J. Jenkins, S. Khatiwala, S. Pfirman, and W. M. Smethie. Pathways and mean residence times of dissolved pollutants in the ocean derived from transient tracers and stable isotopes. Science of the Total Environment, 238:15–30, 1999.
  • R. Weppernig, P. Schlosser, S. Khatiwala, and R. G. Fairbanks. Isotope data from Ice Station Weddell: Implications for deep water formation in the Weddell Sea. J. Geophys. Res., 101:25723–25739, 1996. (PDF)

Research

Anthropogenic carbon in the ocean

Ocean transport time-scales

Transport Matrix Method

Fast spinup of ocean biogeochemical models using matrix-free Newton-Krylov

Transit-Time Distributions (coming soon; in the mean time see here: Matlab TTD scripts )

Iterative methods for fast dynamical spinup of ocean general circulation models (coming soon)

Eddies in the Southern Ocean and anthropogenic carbon uptake (coming soon)


Teaching

S3101 Linear Algebra

G9810 Waves

G4210 Geophysical Fluid Dynamics (2004)

G4210 Geophysical Fluid Dynamics (2005)

G9802 Geochemistry Seminar on Modeling of Paleoceanographic Proxies (2006)

V2100 Climate System (2007) (email me for access to my lecture slides)

G4210 Geophysical Fluid Dynamics (2008)

Numerical modeling of the ocean and atmosphere (coming soon)


Programming

Matlab code

My fortran I/O library

Miscellaneous PETSc Utilities


Useful Links