Oceanographer & Climate Scientist

  • About

  • I am an Assistant Professor at the University of South Florida College of Marine Science in St. Petersburg, Florida. I am interested in studying the ocean's role in the carbon cycle and in climate. For my research I utilize data from autonomous platforms such as robotic profiling floats and Saildrones equipped with biogeochemical sensors, as well as more "traditional" wet chemistry methods. I also analyze output from Earth System Models with the goal of informing model improvement and reducing uncertainties in future climate projections. To date, much of this work has been in the Southern Ocean.

    If you are interested in joining the Williams Lab please fill out this form and Dr. Williams will reach out to you with next steps.

  • Where are the SOCCOM floats now?

  • Follow the link to OceanOPS to see where the SOCCOM floats are today and even plot up the data with just a few clicks!

  • Research Interests

    • the marine carbon system
    • carbonate system chemistry
    • ocean carbon uptake
    • ocean acidification
    • chemical sensors
    • climate quality data
    • Southern Ocean
    • Earth System Model evaluation
    • Open Science


Saildrone completes the first autonomous Antarctic circumnavigation!

August 2019: An article by Saildrone on the exciting completion of the Saildrone's Antarctic Circumnavigation. Preliminary surface ocean CO2 results courtesy of NOAA PMEL, shown in the figure to the left, indicate significant wintertime outgassing in the Southeast Atlantic and Indian sectors, corroborating the results from SOCCOM biogeochemical Argo floats.


  • download cv (updated October 2021)
  • 2021 Tamsitt, V., S. Bushinsky, Z. Li, M. du Plessis, A. Foppert, S. Gille, S.R. Rintoul, E. Shadwick, A. Silvano, A. Sutton, S. Swart, B. Tilbrook, & Williams, N. L.. The Southern Ocean [in “State of the Climate in 2020”]. Bull. Amer. Meteor. Soc. doi: 10.1175/BAMS-D-21-0081.1.
    2021 Lovenduski, N. S., Swart, N. C., Sutton, A. J., Fyfe, J. C., McKinley, G. A., Sabine C., and Williams, N. L.. The Ocean Carbon Response to COVID‐Related Emissions Reductions. Geophysical Research Letters. doi: 10.1029/2020GL092263.
    2021 Sutton, A. J., Williams, N. L., and B. Tillbrook. Constraining Southern Ocean CO2 Flux Uncertainty Using Uncrewed Surface Vehicle Observations. Geophysical Research Letters. doi: 10.1029/2020GL091748. Editor's Highlight by Janet Sprintall
    2020 Bronselaer, B., J. L. Russell, M. Winton, N. L. Williams, R. Key, J. Dunne, R. A. Feely, K. S. Johnson, and J. L. Sarmiento. Importance of wind and meltwater for observed chemical and physical changes in the Southern Ocean. Nature Geoscience. doi: 10.1038/s41561-019-0502-8. Commentary by Alessandro Silvano
    2019 Bushinsky, S. M., Y. Takeshita, and N. L. Williams. Observing changes in ocean carbonate chemistry: Our autonomous future, Current Climate Change Reports, doi: 10.1007/s40641-019-00129-8.
    2019 Carter, B. R., N. L. Williams, W. Evans, A. J. Fassbender, L. Barbero, C. Hauri, R. A. Feely, and A. J. Sutton. Time-of-emergence as a metric for prioritizing between climate observation quality, frequency, and duration, Geophys. Res. Lett., doi: 10.1029/2018GL080773.
    2019 Talley, L. D., I. Rosso, I. Kamenkovich, M. E. Mazloff, J. Wang, E. Boss, A. R. Gray, K. S. Johnson, R. Key, S. C. Riser, N. L. Williams, and J. L. Sarmiento. Southern Ocean biogeochemical float deployment strategies, with example from the Greenwich Meridian line (GO-SHIP A12), J. Geophys. Res. Ocean. SOCCOM Special Issue, doi: 10.1029/2018JC014059.
    2018 Williams, N. L., R. A. Feely, L. W. Juranek, J. L. Russell, K. S. Johnson, and B. Hales. Assessment of the carbonate chemistry seasonal cycles in the Southern Ocean from persistent observational platforms, J. Geophys. Res. Ocean. SOCCOM Special Issue, doi: 10.1029/2017JC012917.
    2018 Bittig, H. C., T. Steinhoff, H. Claustre, B. Fiedler, N. L. Williams, R. Sauzède, A. Körtzinger, and J.-P. Gattuso. An Alternative to Static Climatologies: Robust Estimation of Open Ocean CO2 Variables and Nutrient Concentrations From T, S, and O2 Data Using Bayesian Neural Networks, Front. Mar. Sci., doi: 10.3389/fmars.2018.00328.
    2018 Gray, A. R., K. S. Johnson, S. M. Bushinsky, S. C. Riser, J. L. Russell, L. D. Talley, R. Wanninkhof, N. L. Williams, and J. L. Sarmiento. A Southern Ocean source of carbon dioxide detected with autonomous biogeochemical floats, Geophys. Res. Lett., doi: 10.1029/2018GL078013.
    2018 Fay, A. R., N. S. Lovenduski, G. A. McKinley, D. R. Munro, C. Sweeney, A. R. Gray, P. Landschützer, B. Stephens, T. Takahashi, and N. Williams. Utilizing the Drake Passage Time-series to understand variability and change in subpolar Southern Ocean pCO2, Biogeosciences, doi: 10.5194/bg-2017-489.
    2017 Carter, B., R. A. Feely, N. L. Williams, A. G. Dickson, M. B. Fong, and Y. Takeshita. Updated Methods for Global Locally-Interpolated Estimation of Alkalinity, pH, and Nitrate, Limnology and Oceanography: Methods, doi: 10.1002/lom3.10232.
    2017 Johnson, K. S., J. Plant, L. Coletti, H. Jannasch, C. Sakamoto, S. Riser, D. Swift, J. L. Sarmiento, L. D. Talley, and N. L. Williams. Chemical sensor performance in the SOCCOM profiling float array, J. Geophys. Res. Ocean. SOCCOM Special Issue, doi: 10.1002/2017JC012838.
    2017 Williams, N. L., L. W. Juranek, R. A. Feely, K. S. Johnson, J. L. Sarmiento, L. D. Talley, J. L. Russell, S. C. Riser, A. G. Dickson, A. R. Gray, R. Wanninkhof, and Y. Takeshita. Calculating surface ocean pCO2 from biogeochemical Argo floats: An uncertainty analysis, Global Biogeochem. Cycles, 31, doi: 10.1002/2016GB005541. Commentary by Are Olsen
    2016 Wanninkhof, R. et al., An evaluation of pH and NO3 sensor data from SOCCOM floats and their utilization to develop ocean inorganic carbon products: A summary of discussions and recommendations of the Carbon Working Group (CWG) of SOCCOM, Princeton Environmental Institute, Princeton, New Jersey. Link to report.
    2016 Williams, N. L., L. W. Juranek, K. S. Johnson, R. A. Feely, S. C. Riser, L. D. Talley, J. L. Russell, J. L. Sarmiento, and R. Wanninkhof. Empirical algorithms to estimate water column pH in the Southern Ocean, Geophys. Res. Lett., 43(7), 3415–3422, doi: 10.1002/2016GL068539.
    2016 Carter, B., N. L. Williams, R. A. Feely, and A. Gray. Locally Interpolated Alkalinity Regression for Global Alkalinity Estimation, Limnology and Oceanography: Methods. doi:10.1002/lom3.10087.
    2015 Williams, N. L., R. A. Feely, C. L. Sabine, A. G. Dickson, J. H. Swift, L. D. Talley, and J. L. Russell, Quantifying Anthropogenic Carbon Inventory Changes in the Pacific Sector of the Southern Ocean, Mar. Chem., 174, 147–160, doi:10.1016/j.marchem.2015.06.015.
    2009 Millero, F. J., F. Huang, N. Williams, J. Waters, and R. Woosley. The effect of composition on the density of South Pacific Ocean waters, Mar. Chem., 114(1–2), 56–62, doi:10.1016/j.marchem.2009.04.001.


As we continue to harm our planet through fossil fuel burning, cement production, and land-use changes there is a growing need for scientists to communicate effectively to the public about climate science. Over time I have realized that for a public audience it is not necessary for me to be able to explain every detail about my research, but rather that I be able to talk about the basics of oceanography and climate science. I am working to improve my skills at every opportunity and in the past I have volunteered at NOAA in Seattle to present to groups of visiting college students about the work of the PMEL marine carbon group. I also volunteered in summers during graduate school to lead activities about ocean circulation for NOAA Science Camp where middle schoolers spend a week learning about earth and ocean sciences, and I volunteered during the school year with the Seattle Association for Women in Science (AWIS) Girls in Engineering, Math, and Science (GEMS) program. I participated in ComSciCon-PNW 2017, The Communicating Science workshop for graduate students at Google Seattle in 2017 and am enjoying putting my new science communication skills into action.

Here at USF CMS, my lab group has developed an interactive Saildrone data-based lesson hosted on a Binder for our college's Oceanography Camp for Girls. This lab shows campers how we use robots to observe remote ocean regions and introduces ideas like the interplay between the ocean and the atmosphere, and between ocean biology, chemistry, and physics. It also gives the campers hands on experience doing coding and data analysis using Python and interactive Jupyter Notebooks. Run the code for yourself here!


I have been lucky to visit some pretty special places during my work and studies in oceanography. Here are a few photos:

Landing on the Ross Sea

In 2011 I traveled to McMurdo base on the Antarctic Continent to participate in the S04P CLIVAR Repeat Hydrography cruise. We sailed for 64 days from McMurdo to Punta Arenas, Chile. The airstrip at McMurdo was literally on top of the Ross Sea ice!

Icebergs and Glaciers

Icebergs traveling out of the Ross Sea with immense glaciers in the background.

Adelie indecision

These two Adelie penguins had probably never seen a ship before and I'm not sure they knew what to do.

Easter Island

After journeying from San Diego to Easter Island during the 2007 holiday season taking water samples along the way we were rewarded with a visit to the famous Moai of Rapa Nui.

Sampling for CO2 in the Arctic Ocean

In August of 2015 I sailed on the NOAA ship Ronald H. Brown to the Arctic Ocean to measure CO2 in the water column. The seawater was near freezing!

In my spare time...

I enjoy traveling to places where the water is warm and fly fishing for the elusive bonefish. Here I am on a mudflat at low tide in the Bahamas. Lots of fish food living in those holes!