Publications

Works in progress:

Tyler, R. H., D. S. Trossman: Oceanic and Ionospheric Tidal Magnetic Fields Extracted From Global Geomagnetic Observatory Data. submitted to Philosophical Transactions  of the Royal Society A.

Lavin, P. D., D. A. Byrne, D. S. Trossman, L. J. Gramer: Evaluating Tropical Cyclone Intensity Forecasts Using Satellite-Derived Ocean Profiles.  in prep for BAMS.

Trossman, D. S., R. H. Tyler, H. Pillar: The Ocean Circulation-Induced Magnetic Field and Its Physical Oceanographic Information.  submitted to Philosophical Transactions of the Royal Society A.

Trossman, D. S., P. D. Lavin, D. A. Byrne, L. J. Gramer: NOAA Next-Generation Enterprise Ocean Heat Content Algorithm Innovations for Operational Use in the North Atlantic Ocean.  in prep

2023:

Sulpis, O., D. S. Trossman, M. Holzer, E. Jeansson, S. K. Lauvset, J. J. Middelburg, 2023: Respiration patterns in the dark ocean.  Global Biogeochemical Cycles, 37, e2023GB007747; https://doi.org/10.1029/2023GB007747

Developed a method to estimate respiration rates based on transit-time distribution-based mean ages and dissolved oxygen concentrations via calculation of total oxygen utilization (instead of apparent oxygen utilization) and found a surprising amount of respiration occurs in the abyssal ocean, which is balanced by sediment oxygen consumption and organic carbon consumption

*My role in this project was to help initiate the project idea by suggesting the we calculate total oxygen utilization using observationally-derived transit-time distributions, which turned into using preformed oxygen from an inverse biogeochemical model estimate, and to help develop the methods, such as the use of neutral isopycnal surfaces to sort total oxygen utilization in the method

2022:

Trossman, D. S., R. H. Tyler, 2022: Oceanic electrical conductivity variability from observations and its budget from an ocean state estimate.  Geophysical Research Letters, 49, e2022GL100453; https://doi.org/10.1029/2022GL100453

Found close agreement between the ECCO version 4, release 3 state estimate's representation of the ocean's electrical conductivity with to the World Ocean Atlas (2018) climatology and sea surface conductivity from OISST and SMAP/SMOS down to several thousand meters depth, and demonstrated with ECCO that the variability in the ocean's electrical conductivity content and that in the ocean's heat content is primarily driven by a common source: ocean heat uptake

Trossman, D. S., C. Whalen, T. W. N. Haine, A. F. Waterhouse, A. T. Nguyen, A. Bigdeli, M. Mazloff, P. Heimbach, 2022: Tracer and Observationally Derived Constraints on Diapycnal Diffusivities in an Ocean State Estimate.  Ocean Science, 18, 729-759; https://doi.org/10.5194/os-18-729-2022

Suggested, using evidence from adjoint sensitivity calculations, that the disagreements between diapycnal diffusivities from observations and diapycnal diffusivities from an ocean state estimate can be assuaged by constraining the ocean state estimate with dissolved oxygen concentration observations; also, a sequential data assimilation system's reanalysis product's diapycnal diffusivities are enormous compared to a free-running model-equivalent's diapycnal diffusivities, the latter of which agrees well with observations

Trossman, D. S., R. H. Tyler, 2022: A Prototype for Remote Monitoring of Ocean Heat Content Anomalies.  Journal of Atmospheric and Oceanic Technology, 39(5), 667-688; https://doi.org/10.1175/JTECH-D-21-0037.1

Demonstrated using output of an ocean state estimate that it might be possible to remotely monitor ocean heat content on multi-year time scales by training a machine-learning algorithm on ship-based hydrographic observations along the transects where they have historically been sampled (supplemented with any deep Argo or other observations that sample the full water column) if there are sufficiently small measurement errors for sea surface heights from altimetry, bottom pressures from gravimetry, and electrical conductivity content from magnetometry

Trossman, D. S., E. Bayler, 2022: An Algorithm to Bias-Correct and Transform Arctic Satellite-Derived Skin Salinities to Bulk Surface Salinities.  Remote Sensing, 14(6), 1418; https://doi.org/10.3390/rs14061418

Derived a machine-learning algorithm that both bias-corrects and converts skin surface salinities derived from Level-2 SMAP data to bulk surface salinities appropriate for data assimilation with ocean models; the bias-correction cuts the root-mean-square error relative to in-situ observations in half with the use of OAFlux forcing/flux fields, as they likely correct for errors in the ancillary winds, sea surface temperatures, and sea-ice data used in the SMAP retrievals

2021:

Harvey, T. C., B. D. Hamlington, T. Frederikse, R. S. Nerem, C. G. Piecuch, W. C. Hammond, G. Blewitt, P. R. Thompson, D. P. S. Bekaert, F. W. Landerer, J. T. Reager, R. E. Kopp, H. Chandanpurkar, I. Fenty, D. Trossman, J. S. Walker, C. Boening, 2021: Ocean mass, sterodynamic effects, and vertical land motion largely explain US coast relative sea level rise. Communications Earth & Environment, 2:233; https://doi.org/10.1038/s43247-021-00300-w

Performed a sea level budget analysis in terms of ocean mass change, sterodynamic effects, and vertical land motions using tide gauge observations and showed that these terms can explain the trends in 47 of 55 locations around the U.S.

*My role in this project was to suggest how to perform the sterodynamic effect calculations and what could be causing the discrepancies in the budget analyses

2020:

Hamlington, B. D., A. S. Gardner, E. Ivins, J. T. M. Lenaerts, J. T. Reager, D. S. Trossman, E. D. Zaron, S. Adhikari, A. Arendt, A. Aschwanden, B. D. Beckley, D. P. S. Bekaert, G. Blewitt, L. Caron, H. A. Chandanpurkar, K. Christianson, R. I. Cullather, R. M. DeConto, J. T. Fasullo, T. Frederikse, J. T. Freymueller, D. M. Gilford, M. Girotto, W. C. Hammond, R. Hock, N. Holschuh, R. E. Kopp, F. Landerer, E. Larour, D. Menemenlis, M. Merrifield, J. X. Mitrovica, R. S. Nerem, I. J. Nias, V. Nieves, S. Nowicki, K. Pangaluru, C. G. Piecuch, D. R. Rounce, N.-J. Schlegel, H. Seroussi, M. Shirzaei, I. Velicogna, N. Vinogradova, T. Wahl, D. N. Wiese, M. J. Willis, 2020: Understanding of contemporary regional sea-level change and the implications for the future.  Reviews of Geophysics, 59, e2019RG000672; https://doi.org/10.1029/2019RG000672

Reviewed efforts to better understand recent historical sea level changes from the perspective of scientists who tend to use a combination of satellite observations and models

*My role in this manuscript was to write and lead the section on Steric Sea Level and Ocean Dynamics

2019:

T. M. S. Johnston, M. C. Schönau, T. Paluszkiewicz, J. A. MacKinnon, B. K. Arbic, P. L. Colin, M. H. Alford, M. Andres, L. Centurioni, K. R. Helfrich, V. Hormann, P. F. J. Lermusiaux, R. C. Musgrave, B. S. Powell, B. Qiu, D. L. Rudnick, H. L. Simmons, L. St. Laurent, D. S. Trossman, G. Voet, H. W. Wijesekera, K. Zeiden, 2019: An Introduction and Highlights from Flow Encountering Abrupt Topography (FLEAT): A Multi-Scale Observational and Modelling Program to Understand the Effects of Topographic Flow in the Western North Pacific.  Oceanography, 32(4), 10-21; https://doi.org/10.5670/oceanog.2019.407

Described a recent campaign called Flow Encountering Abrupt Topography (FLEAT) that aimed to better understand the role of island chains and ridges in open ocean current systems

*My role in this manuscript was to make a close-up of the map of spatial variations in mechanical energy dissipation due to the topographic wave drag

Arbic, B. K., O. B. Fringer, J. M. Klymak, F. T. Mayer, D. S. Trossman, P. Zhu, 2019: Connecting process models of topographic wave drag to global eddying general circulation models.  Oceanography, 32(4), 146-155; https://doi.org/10.5670/oceanog.2019.420.

Described recent efforts to understand the momentum sink imparted on the background flows due to the breaking of waves generated by flows impinging and propagating over topographic features, ranging from process studies to global eddying general circulation ocean models that are high resolution but not high enough resolution to resolve such internal lee waves

*My role in this manuscript was to summarize the efforts made using global eddying general circulation ocean models and to make the map of the spatial variations in mechanical energy dissipation due to the topographic wave drag

Sulpis, O., C. Dufour, D. S. Trossman, A. S. Fassbender, A. Mucci, B. K. Arbic, B. P. Boudreau, 2019: Reduced CaCO3 flux to the seafloor and weaker bottom current speeds curtail benthic CaCO3 dissolution over the 21st century.  Global Biogeochemical Cycles, 33, https://doi.org/10.1029/2019GB006230

Investigated whether future changes in calcium carbonate flux to the seafloor and/or near-bottom ocean currents would determine future seafloor dissolution rates according to CMIP5 and other model simulations, and found that the poorly known changes in calcium carbonate flux to the seafloor will probably determine the trend in future seafloor dissolution rates, despite consensus agreement that future near-bottom ocean currents will be weaker

*My role in this manuscript was to provide a high resolution near-bottom ocean currents product and current meter observations as well as guidance with the part of the analysis that addresses how well models agree with current meter observations

Heimbach, P., I. Fukumori, C. N. Hill, R. M. Ponte, D. Stammer, C. Wunsch, J.-M. Campin, B. Cornuelle, I. Fenty, G. Forget, A. Köhl, M. Mazloff, D. Menemenlis, A. T. Nguyen, C. Piecuch, D. Trossman, A. Verdy, O. Wang, H. Zhang, 2019: Putting it all together: Adding value to the global ocean and climate observing systems with complete self-consistent ocean state and parameter estimates. Frontiers in Marine Science, 6:55, https://doi.org/10.3389/fmars.2019.00055

Reviewed efforts to develop the Estimating the Circulation & Climate of the Ocean state estimation framework and future directions for further improvement

*My role in this manuscript was to describe two advances I've been contributing to related to the information provided by ocean mixing parameters (inferred from finestructure observations and theory) and by electrical conductivity (inferred from geomagnetic field observations)

Trossman, D. S., R. H. Tyler, 2019: Predictability of Ocean Heat Content from Electrical Conductance.  Journal of Geophysical Research-Oceans, 124, 667-679, https://doi.org/10.1029/2018JC014740

Inspected whether ocean heat content could be estimated from perfectly-known depth-integrated and/or -averaged conductivity fields on regional and global scales, found that this can be done to within 0.1% (1%) error on annual (bidecadal) time scales, the accuracy is particularly high in places with a dearth of in situ observations because of being covered by sea ice, and regions where ocean heat content can be predicted more accurately than ocean salt content are locations where variations on conductivity due to temperature dominates those due to salinity; note that this paper has a Corrigendum that we sent to the editor

2018:

Sulpis, O., B. P. Boudreau, A. Mucci, C. Jenkins, D. S. Trossman, B. K. Arbic, R. M. Key, 2018: Current CaCO3 Dissolution at the Seafloor Caused by Anthropogenic CO2. Proceedings of the National Academy of Science of the USA, 115(45), 11700-11705, https://doi.org/10.1073/pnas.1804250115

Investigated the evidence for whether there is an anthropogenic signal in calcium carbonate dissolution near the seafloor using theory for a rate model and our best estimates of the bottom-water chemistry, benthic currents, and calcium carbonate content of deep-sea sediments, found that 40-100% of near-seafloor dissolution in the northwestern Atlantic Ocean (where the calcium compensation depth has risen a few hundred meters) is due to human emissions and there are many other hot spots of dissolution in each sector of the Southern Ocean

*My role in this manuscript was to provide the benthic currents product and description of the method to derive it

Palter, J. B., D. S. Trossman (co-first authors), 2018: The Sensitivity of Future Ocean Oxygen Concentrations to Changes in Ocean Circulation. Global Biogeochemical Cycles, 32, 738-751, https://doi.org/10.1002/2017GB005777

Studied the extent to which ocean deoxygenation in a future climate scenario depends upon the large-scale ocean circulation, found that the large-scale ocean circulation perturbation buffers about 20% of the oxygen decrease, oxygen in the Southern Ocean is the most sensitive to any circulation changes, the Atlantic Meridional Overturning Circulation slowdown increases ideal ages but has little impact on deoxygenation due to the slowness of respiration at deep depths in the Atlantic Ocean, the weakening Walker Circulation slows export productivity and respiration in the eastern equatorial Pacific such that intensification of hypoxia there is assuaged, and deoxygenation is mostly determined by changes in subgridscale processes such as turbulent mixing and secondarily by solubility changes

2017:

Luecke, C. A., S. L. Bassette, B. K. Arbic, J. G. Richman, J. F. Shriver, D. F. Furnival, E. J. Metzger, R. B. Scott, O. M. Smedstad, P. G. Timko, D. S. Trossman, A. J. Wallcraft, 2017: Global Model-Data Comparison of Low Frequency Eddy Available Potential Energy. J. Geophys. Res.-Oceans, 112, 9126-9143, https://doi.org/10.1002/2017JC013136

Evaluated the ability of several models to capture the low frequency eddy available potential energy of the ocean against Argo and current meter observations and found adequate agreement, given the expected scatter due to the timing of eddies

*My role in this manuscript was to help with some of the data analysis and model-data comparisons

Trossman, D. S., B. K. Arbic, D. Straub, J. Richman, E. Chassignet, A. J. Wallcraft, X. Xu, 2017: The Role of Rough Topography in Mediating Impacts of Bottom Drag in Eddying Ocean Circulation Models.  J. Phys. Oceanogr., 47, 1941-1959. https://doi.org/10.1175/JPO-D-16-0229.1

Systematically evaluated whether rough, as opposed to flat, bottom topography can explain the much reduced sensitivity of eddy statistics to bottom drag strength and the presence of wave drag in realistic ocean general circulation models relative to idealized quasi-geostrophic models

MacKinnon, J., Z. Zhao, C. B. Whalen, A. F. Waterhouse, D. S. Trossman, O. M. Sun, L. C. St. Laurent, H. L. Simmons, K. Polzin, R. Pinkel, A. Pickering, N. J. Norton, J. D. Nash, R. Musgrave, L. M. Merchant, A. V. Melet, B. Mater, S. Legg, W. G. Large, E. Kunze, J. M. Klymak, M. Jochum, S. R. Jayne, R. W. Hallberg, S. M. Griffies, S. Diggs, G. Danabasoglu, E. P. Chassignet, M. C. Buijsman, F. O. Bryan, B. P. Briegleb, A. Barna, B. K. Arbic, J. K. Ansong, M. H. Alford, 2017: Climate Process Team on Internal-Wave Driven Ocean Mixing.  Bulletin of the American Meteorological Society, 98(11), 2429-2454. https://doi.org/10.1175/BAMS-D-16-0030.1

Reviewed recent advances in our understanding of internal wave-driven turbulent mixing and summarized available parameterizations for use in global climate models

*My role in this manuscript was to write a significant portion of the section on internal lee waves and provide one of the panels for the figures

2016:

Trossman, D. S., J. B. Palter, T. M. Merlis, Y. Huang, Y. Xia, 2016: Large-scale ocean circulation-cloud interactions reduce the pace of transient climate change.  Geophys. Res. Lett., 43, 3935-3943, https://doi.org/10.1002/2016GL067931

Studied the impact of ocean circulation-cloud interactions on transient climate change, found that these interactions contribute a cooling effect (in addition to the cooling effect due to a weakening oceanic overturning circulation), inferred that this cooling effect is a result of low cloud coverage maintenance (due to the influence the ocean circulation changes have on the inversion strength of and moisture flux to the lower troposphere), and suggested that uncertainty in large-scale ocean circulation changes under anthropogenically forced climate change could account for a large fraction of the spread in the radiative cloud feedback amongst climate models

Palter, J. B., C.-A. Caron, K. L. Law, J. K. Willis, D. S. Trossman, I. M. Yashayaev, and D. Gilbert, 2016: Variability of the directly-observed, mid-depth subpolar North Atlantic circulation. Geophys. Res. Lett., 42, 2700-2708, https://doi.org/10.1002/2015GL067235

Examined whether changes in the subpolar North Atlantic Ocean circulation can be detected from profiler measurements, found that there is a statistically significant decline in the Labrador Sea boundary currents from 1997 to 2013, and developed a method to detect topographic steering with float data

*My role in this project was to provide statistical support on the objective interpolation techniques

Trossman, D. S., B. K. Arbic, J. G. Richman, S. T. Garner, S. R. Jayne, A. J. Wallcraft, 2016: Impact of Topographic Internal Lee Wave Drag on an Eddying Global Ocean Model. Ocean Modelling, 97, 109-128; http://dx.doi.org/10.1016/j.ocemod.2015.10.013

Examined the impact of the combined drag associated with lee wave generation and topographic blocking on the eddying circulation of an ocean model at two different resolutions, found that the impacts are profound in the abyss and small but non-zero at the surface due to altered baroclinic instability, and introduced a metric which suggests that the vertical deposition of lee wave momentum flux should be horizontally heterogenous

2015:

Trossman, D. S., S. Waterman, K. L. Polzin, B. K. Arbic, S. T. Garner, A. C. Naveira-Garabato, K. L. Sheen, 2015: Internal Lee Wave Closures: Parameter Sensitivity and Comparison to Observations. Journal of Geophysical Research-Oceans, 120, 7997-8019, https://doi.org/10.1002/2015JC010892

Compared two different lee wave closures with each other and with observations, found that they're all within a factor of two of each other in a horizontal spatial average, that the two closures differ in their representation of topographic blocking, and that topographic blocking accounts for the majority of the dissipation in the bottom 1000 meters of the water column where the dissipation rate predictions agree most closely with the dissipation rates from observations

2014:

Trossman, D. S., L. Thompson, S. Mecking, M. J. Warner, F. Bryan, S. Peacock, 2014: Evaluation of Oceanic Transport Parameters Using Transient Tracers From Observations and Model Output. Ocean Modelling, 74, 1-21. https://doi.org/10.1016/j.ocemod.2013.11.001

Estimated mean ages and their uncertainties along several hydrographic cross-sections, suggested that the simple analytical transit-time distribution previous studies used is insufficient in the Southern Ocean, and developed a method to evaluate whether model biases in tracer concentrations arise due to errors in mean advection time from the surface or other processes

2013:

Trossman, D. S., B. K. Arbic, S. T. Garner, J. A. Goff, S. R. Jayne, E. J. Metzger, A. J. Wallcraft, 2013: Impact of Parameterized Lee Wave Drag on the Energy Budget of an Eddying Global Ocean Model. Ocean Modelling, 72, 119-142. https://doi.org/10.1016/j.ocemod.2013.08.006

Inserted an atmospheric scheme for the momentum sink associated with flow-topography interaction (i.e., lee wave generation and topographic blocking) into a high-resolution ocean model without tides and balanced the total potential plus kinetic energy budget to within 10%

2012:

Trossman, D. S., L. Thompson, S. Mecking, M. J. Warner, 2012: On the Formation, Ventilation, and Erosion of Mode Waters in the North Atlantic and Southern Oceans. Journal of Geophysical Research-Oceans, 117, C09026, https://doi.org/10.1029/2012JC008090

Compared two methods of estimating ventilation rates, found that mixing along isopycnal outcrops can contribute to a significant fraction of mode water ventilation, and looked at how three different mode waters form and erode in different ways

2011:

Trossman, D. S., L. Thompson, S. L. Hautala, 2011: Application of Thin-Plate Splines in Two-Dimensions to Oceanographic Tracer Data. Journal of Atmospheric and Oceanic Technology, 28(11), 1522-1538. https://doi.org/10.1175/JTECH-D-10-05024.1

Compared optimal interpolation with a machine learning technique to map hydrographic data along cross-sections onto a regular grid and found that the uncertainties associated with the machine learning estimates are conservative estimates for the mapping errors on the optimal interpolation estimates

2009:

Trossman, D. S., L. Thompson, K. A. Kelly, Y.-O. Kwon, 2009: Estimates of North Atlantic Ventilation and Mode Water Formation for Winters 2002-06. Journal of Physical Oceanography, 39(10), 2600-2617. https://doi.org/10.1175/2009JPO3930.1

Analyzed observations of subtropical mode water in the North Atlantic Ocean, found that the low Rossby number-based Ekman pumping approximation is typically accurate, and suggested that lateral advection dominates Ekman pumping in purely advective ventilation rate estimates

2007:

Campbell, J. A., D. S. Trossman, W. Yokoyama, L. Carayannopoulos, 2007: Zoonotic Orthopoxviruses Encode a High-Affinity Antagonist of NKG2D. Journal of Experimental Medicine, 204(6), 1311-1317. https://doi.org/10.1084/jem.20062026

*My role in this project was to write a script that utilizes a Hidden Markov Model, which was automated to churn through a database of protein RNA

Not peer-reviewed:

Trossman, D. S., J. B. Palter, 2021: Changing Ocean Currents. In: Conrad K. (eds) From "Hurricanes to Epidemics. Global Perspectives on Health Geography." Springer, Cham. https://doi.org/10.1007/978-3-030-55012-7_2

Arbic, B. K., M. C. Buijsman, E. P. Chassignet, S. T. Garner, S. R. Jayne, E. J. Metzger, J. G. Richman, J. F. Shriver, P. G. Timko, D. S. Trossman, A. J. Wallcraft, 2014: Inserting tides and topographic wave drag into high-resolution eddying simulations.  CLIVAR Exchanges, 65, 30-33.

Trossman, D. S., 2011: Advection-Diffusion Process Inference via Statistical Oceanographic Methods in the North Atlantic and Southern Oceans. PhD Thesis, University of Washington.