Implementation of FAIR principles in the IPCC: the WGI AR6 Atlas repository

The Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) has adopted the FAIR Guiding Principles. We present the Atlas chapter of Working Group I (WGI) as a test case. We describe the application of the FAIR principles in the Atlas, the challenges faced during its implementation, and those that remain for the future. We introduce the open source repository resulting from this process, including coding (e.g., annotated Jupyter notebooks), data provenance, and some aggregated datasets used in some figures in the Atlas chapter and its interactive companion (the Interactive Atlas), open to scrutiny by the scientific community and the general public. We describe the informal pilot review conducted on this repository to gather recommendations that led to significant improvements. Finally, a working example illustrates the re-use of the repository resources to produce customized regional information, extending the Interactive Atlas products and running the code interactively in a web browser using Jupyter notebooks.Peer reviewe

Numerical Simulation of Admiralty Inlet, WA, with Tidal Hydrokinetic Turbine Siting Application

Thesis (Ph.D.)--University of Washington, 2012Tidal hydrokinetic energy has been recognized as a potential source of sustainable, renewable energy. In order to properly site turbines for commercial-scale development, the complex flow conditions in a potential deployment region must be understood. Viable locations for turbines are limited by many factors, including underwater space that is above the bottom boundary layer, below shipping traffic, within areas of strong currents, and yet avoids additional fatiguing stresses. The primary area of interest in the Puget Sound for commercial tidal energy development is Admiralty Inlet, which includes potentially disruptive flow features such as vortices and strong turbulence. This dissertation seeks to increase the body of knowledge of these features both from an oceanographic perspective and as they pertain to turbine site characterization. The primary means of studying Admiralty Inlet in this document is through numerical simulation of the region using the Regional Ocean Modeling System (ROMS). The model output is found to compare well with field data, capturing eddy fields, turbulence properties, relative tidal phases, and illuminating many flow features. Horizontal velocities in the simulation are, on average, approximately 75\% the size of those found in the data. This speed deficiency is inherited from the forcing model in which the Admiralty Inlet simulation is nested. The model output also shows that the flow field of this fjord-like estuary is largely affected by a headland on the northeast side of the Inlet. Vortices generated by this headland, Admiralty Head, are found to vary considerably depending on the tidal cycle. The eddies can persist beyond the half-cycle of generation to significantly affect the horizontal speed and other flow field properties in the subsequent half-cycle. Detailed analysis of the vertical vorticity governing equation shows that advection, tilting, stretching, and boundary generation are the most significant processes dictating the behavior of the vorticity. Turbulence modeling in the simulation is carried out via a k-&epsilon turbulence closure scheme. Comparisons of model output with high resolution field data show the model to perform reasonably well: predicted Reynolds stress and turbulent dissipation rate values are usually within a factor of two of the field data. The turbulent kinetic energy from the simulation compares well with field data that is restricted to the frequency range of classical turbulence. The energy density spectrum of the data is found to follow Kolmogorov's theory beyond the inertial subrange. Using this fact and Taylor's frozen field approximation, an inferred calculation for the turbulent kinetic energy is derived that spans the full frequency range of the data set. The output from the inferred calculation compares well with the full turbulent kinetic energy from the field data. Maps of metrics for tidal turbine siting are generated that address many considerations for turbine placement, and can be adjusted for the model's speed deficiency with a simple multiplication factor. Among the possible best locations for turbine deployment are north of Point Wilson on the west side of Admiralty Inlet and near the center of the channel between Point Wilson and Admiralty Head. These locations have a strong tidal resource available along with highly bi-directional tidal currents and low turbulence levels

Supplementary MATLAB toolbox and data for "Comparative evaluation of volumetric current measurements in a tidally-dominated, coastal setting with an emphasis on float swarms"

These files comprise the MATLAB code used to generate the results presented in "Comparative evaluation of volumetric current measurements in a tidally-dominated, coastal setting with an emphasis on float swarms," written by Trevor Harrison (University of Washington), Kristen M. Thyng (Texas A&M University), and Brian Polagye (Univeristy of Washington). The code was based on the outputs of a previous hydrodynamic simulation of Admiralty Inlet, Puget Sound, WA. Those outputs are separately available at http://pong.tamu.edu/~kthyng/froude/ai65/OUT/ and managed by Kristen Thyng (kthyng [at] tamu.edu). Further information regarding implementation of the toolbox can be found in the README.txt tile, as well as comments embedded in scripts and functions. The code was last known to be stable on MATLAB2018b.This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1762114. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation

Dissolved Iron and Iron Isotopes in the Southeastern Pacific Ocean

The Southeast Pacific Ocean is a severely understudied yet dynamic region for trace metals such as iron, since it experiences steep redox and productivity gradients in upper waters and strong hydrothermal iron inputs to deep waters. In this study, we report the dissolved iron (dFe) distribution from seven stations and Fe isotope ratios (δ56Fe) from three of these stations across a near‐zonal transect from 20 to 27°S. We found elevated dFe concentrations associated with the oxygen‐deficient zone (ODZ), with light δ56Fe implicating porewater fluxes of reduced Fe. However, temporal dFe variability and rapid δ56Fe shifts with depth suggest gradients in ODZ Fe source and/or redox processes vary over short‐depth/spatial scales. The dFe concentrations decreased rapidly offshore, and in the upper ocean dFe was controlled by biological processes, resulting in an Fe:C ratio of 4.2 µmol/mol. Calculated vertical diffusive Fe fluxes were greater than published dust inputs to surface waters, but both were orders of magnitude lower than horizontal diffusive fluxes, which dominate dFe delivery to the gyre. The δ56Fe data in the deep sea showed evidence for a −0.2‰ Antarctic Intermediate Water end‐member and a heavy δ56Fe of +0.55‰ for distally transported hydrothermal dissolved Fe from the East Pacific Rise. These heavy δ56Fe values were contrasted with the near‐crustal δ56Fe recorded in the hydrothermal plume reaching Station ALOHA in the North Pacific. The heavy hydrothermal δ56Fe precludes a nanopyrite composition of hydrothermal dFe and instead suggests the presence of oxides or, more likely, binding of hydrothermal dFe by organic ligands in the distal plume

Dissolved Iron and Iron Isotopes in the Southeastern Pacific Ocean

The Southeast Pacific Ocean is a severely understudied yet dynamic region for trace metals such as iron, since it experiences steep redox and productivity gradients in upper waters and strong hydrothermal iron inputs to deep waters. In this study, we report the dissolved iron (dFe) distribution from seven stations and Fe isotope ratios (δ56Fe) from three of these stations across a near‐zonal transect from 20 to 27°S. We found elevated dFe concentrations associated with the oxygen‐deficient zone (ODZ), with light δ56Fe implicating porewater fluxes of reduced Fe. However, temporal dFe variability and rapid δ56Fe shifts with depth suggest gradients in ODZ Fe source and/or redox processes vary over short‐depth/spatial scales. The dFe concentrations decreased rapidly offshore, and in the upper ocean dFe was controlled by biological processes, resulting in an Fe:C ratio of 4.2 µmol/mol. Calculated vertical diffusive Fe fluxes were greater than published dust inputs to surface waters, but both were orders of magnitude lower than horizontal diffusive fluxes, which dominate dFe delivery to the gyre. The δ56Fe data in the deep sea showed evidence for a −0.2‰ Antarctic Intermediate Water end‐member and a heavy δ56Fe of +0.55‰ for distally transported hydrothermal dissolved Fe from the East Pacific Rise. These heavy δ56Fe values were contrasted with the near‐crustal δ56Fe recorded in the hydrothermal plume reaching Station ALOHA in the North Pacific. The heavy hydrothermal δ56Fe precludes a nanopyrite composition of hydrothermal dFe and instead suggests the presence of oxides or, more likely, binding of hydrothermal dFe by organic ligands in the distal plume

Seaweed Paddock: Initial Modeling and Design for a Sargassum Ranch

This paper describes the “SeaweedPaddock” system to profitably grow and harvest open-ocean Sargassum sp. as a sustainable source of macroalgal biomass and biofuel. The US Department of Energy Advanced Research Projects Agency - Energy (ARPA-E) initiated the MacroAlgae Research Inspiring Novel Energy Research (MARINER) program to develop technologies to eventually sustainably harvest macroalgae at 80 per dry metric ton (DMT). The University of Southern Mississippi team is characterizing an unmoored SeaweedPaddock; analyses include tow speed and energy required to avoid hazards, farm design to minimize biomass loss, economical harvesting, and nutrient supply. Initial results indicate that nighttime “smart towing” could allow the SeaweedPaddock system to produce macroalgae at full scale at costs below the ARPA-E goal provided that Sargassum grows at sufficient rates during the day after having been confined all night in a moving fence and that sufficient nutrients are made available. Cost projections for a successful, intensive, scaled system could be competitive with current prices for fossil fuels