Category: Scientific Papers (Abstract & PDF)

Integrated Ocean Carbon

IOC-R. 2021. Integrated Ocean Carbon Research: A Summary of Ocean Carbon Research, and Vision of Coordinated Ocean Carbon Research and Observations for the Next Decade. R. Wanninkhof, C. Sabine and S. Aricò (eds.). Paris, UNESCO. 46 pp. (IOC Technical Series, 158.) doi:10.25607/h0gj-pq41 

Introduction: Knowledge of the ocean carbon cycle is critical in light of its role in sequestering CO2 from the atmosphere and for meeting goals and targets such as the UN Framework Convention on Climate Change (UNFCCC) Paris Agreement, the UN 2030 Agenda for Sustainable Development, and the associated UN Decade of Ocean Science for Sustainable Development. Increasing levels of CO2 in the ocean, predominantly due to human greenhouse gas emissions, and the partitioning of CO2 into organic and inorganic species have fundamental impacts on ocean carbon cycling and ecosystem health. The Integrated Ocean Carbon Research (IOC-R) effort aims to address key issues in ocean carbon research through investigative and observational goals. It takes advantage of the appreciable knowledge gained from studies over the last four decades of the ocean carbon cycle and its perturbations.

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A quantitative and qualitative decision-making process for selecting indicators to track ecosystem condition

Montenero, K., Kelble, C., & Broughton, K. (2021). A quantitative and qualitative decision-making process for selecting indicators to track ecosystem condition. Marine Policy, 129, 104489.

Abstract: Ecosystem indicators are a well-established method for tracking ecosystem conditions and trends with the purpose of informing ecosystem-based management. The selection of indicators is a key step in the management process; however, because 1) selection can be inherently subjective 2) researchers can be entrenched in the ecosystem components they routinely measure, and 3) some voices may be marginalized in a group setting, the selection, prioritization, and consensus processes can be challenging. To overcome these issues, an indicator selection process was developed herein that incorporated expert opinion both qualitatively and quantitatively.

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Surface Expressions of Atmospheric Thermal Tides in the Tropical Atlantic and Their Impact on Open‐ Ocean Precipitation

Christophersen, J. A., Foltz, G. R., & Perez, R. C. (2020). Surface Expressions of Atmospheric Thermal Tides in the Tropical Atlantic and Their Impact on Open‐Ocean Precipitation. Journal of Geophysical Research: Atmospheres, 125(22), e2019JD031997.

Abstract: Diurnal and semidiurnal variations of atmospheric pressure and surface winds are fundamental to the Earth‐Sun system. Past research in the tropical Pacific shows semidiurnal and diurnal patterns in the zonal and meridional wind anomalies, respectively. While the semidiurnal zonal wind pattern is consistent with atmospheric thermal tidal forcing, it is not yet certain what drives diurnal meridional wind variability. This study examines the diurnal cycle of meridional winds in the tropical Atlantic Ocean across four different seasons and the extent to which they impact the diurnal evolution of open‐ocean precipitation in boreal summer. Comparisons of direct observations from long‐term moored buoys to an atmospheric reanalysis (MERRA‐2) show that MERRA‐2 reproduces diurnal and semidiurnal pressure and wind variations…

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Dispersion of Surface Drifters in the Tropical Atlantic

Van Sebille, E., Zettler, E., Wienders, N., Amaral-Zettler, L., Elipot, S., & Lumpkin, R. (2021). Dispersion of surface drifters in the Tropical Atlantic. Frontiers in Marine Science, 7, 1243.

Abstract: The Tropical Atlantic Ocean has recently been the source of enormous amounts of floating Sargassum macroalgae that have started to inundate shorelines in the Caribbean, the western coast of Africa and northern Brazil. It is still unclear, however, how the surface currents carry the Sargassum, largely restricted to the upper meter of the ocean, and whether observed surface drifter trajectories and hydrodynamical ocean models can be used to simulate its pathways. Here, we analyze a dataset of two types of surface drifters (38 in total), purposely deployed in the Tropical Atlantic Ocean in July, 2019. Twenty of the surface drifters were undrogued and reached only ∼8 cm into the water, while the other 18 were standard Surface Velocity Program (SVP) drifters that all had a drogue centered around 15 m depth….

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Ocean Conditions and the Intensification of Three Major Atlantic Hurricanes in 2017

Domingues, R., Le Hénaff, M., Halliwell, G., Zhang, J. A., Bringas, F., Chardon, P., … & Goni, G. (2021). Ocean Conditions and the Intensification of Three Major Atlantic Hurricanes in 2017. Monthly Weather Review, 149(5), 1265-1286.

Major Atlantic hurricanes Irma, Jose, and Maria of 2017 reached their peak intensity in September while traveling over the tropical North Atlantic Ocean and Caribbean Sea, where both atmospheric and ocean conditions were favorable for intensification. In situ and satellite ocean observations revealed that conditions in these areas exhibited (i) sea surface temperatures above 28°C, (ii) upper-ocean heat content above 60 kJ cm−2, and (iii) the presence of low-salinity barrier layers associated with a larger-than-usual extension of the Amazon and Orinoco riverine plumes. Proof-of-concept coupled ocean–hurricane numerical model experiments demonstrated that the accurate representation of such ocean conditions led to an improvement in the simulated intensity of Hurricane Maria for the 3 days preceding landfall in Puerto Rico, when compared to an experiment without the assimilation of ocean observations…..

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A Seasonal Probabilistic Outlook for Tornadoes (SPOTter) in the Contiguous United States Based on the Leading Patterns of Large-Scale Atmospheric Anomalies

Lee, S. K., Lopez, H., Kim, D., Wittenberg, A. T., & Kumar, A. (2021). A Seasonal Probabilistic Outlook for Tornadoes (SPOTter) in the Contiguous United States Based on the Leading Patterns of Large-Scale Atmospheric Anomalies. Monthly Weather Review, 149(4), 901-919.

Abstract: This study presents an experimental model for Seasonal Probabilistic Outlook for Tornadoes (SPOTter) in the contiguous United States for March, April, and May and evaluates its forecast skill. This forecast model uses the leading empirical orthogonal function modes of regional variability in tornadic environmental parameters (i.e., low-level vertical wind shear and convective available potential energy), derived from the NCEP Coupled Forecast System, version 2, as the primary predictors. A multiple linear regression is applied to the predicted modes of tornadic environmental parameters to estimate U.S. tornado activity, which is presented as the probability for above-, near-, and below-normal categories….

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Argo Data 1999–2019: Two Million Temperature-Salinity Profiles and Subsurface Velocity Observations From a Global Array of Profiling Floats

Wong, A. P., Wijffels, S. E., Riser, S. C., Pouliquen, S., Hosoda, S., Roemmich, D., … & Park, H. (2020). Argo Data 1999–2019: Two Million Temperature-Salinity Profiles and Subsurface Velocity Observations From a Global Array of Profiling Floats. Front. Mar. Sci. 7:700. doi: 10.3389/fmars.2020.00700

Abstract: In the past two decades, the Argo Program has collected, processed, and distributed over two million vertical profiles of temperature and salinity from the upper two kilometers of the global ocean. A similar number of subsurface velocity observations near 1,000 dbar have also been collected. This paper recounts the history of the global Argo Program, from its aspiration arising out of the World Ocean Circulation Experiment, to the development and implementation of its instrumentation and telecommunication systems, and the various technical problems encountered….

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OSSE Assessment of Underwater Glider Arrays to Improve Ocean Model Initialization for Tropical Cyclone Prediction

Halliwell Jr, G. R., Goni, G. J., Mehari, M. F., Kourafalou, V. H., Baringer, M., & Atlas, R. (2020). OSSE Assessment of Underwater Glider Arrays to Improve Ocean Model Initialization for Tropical Cyclone Prediction. Journal of Atmospheric and Oceanic Technology, 37(3), 467-487.

Abstract: Credible tropical cyclone (TC) intensity prediction by coupled models requires accurate forecasts of enthalpy flux from ocean to atmosphere, which in turn requires accurate forecasts of sea surface temperature cooling beneath storms. Initial ocean fields must accurately represent ocean mesoscale features and the associated thermal and density structure. Observing system simulation experiments (OSSEs) are performed to quantitatively assess the impact of assimilating profiles collected from multiple underwater gliders deployed over the western North Atlantic Ocean TC region, emphasizing advantages gained by profiling from moving versus stationary platforms. Assimilating ocean profiles collected repeatedly at fixed locations produces large root-mean-square error reduction only within ~50 km of each profiler for two primary reasons…

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Highly variable upper and abyssal overturning cells in the South Atlantic

Kersale, M., Meinen, C. S., Perez, R. C., Le Henaff, M., Valla, D., Lamont, T., … & Garzoli, S. L. (2020). Highly variable upper and abyssal overturning cells in the South Atlantic. Science advances, 6(32), eaba7573.

Abstract: The Meridional Overturning Circulation (MOC) is a primary mechanism driving oceanic heat redistribution on Earth, thereby affecting Earth’s climate and weather. However, the full-depth structure and variability of the MOC are still poorly understood, particularly in the South Atlantic. This study presents unique multiyear records of the oceanic volume transport of both the upper (<~3100 meters) and abyssal (>~3100 meters) overturning cells based on daily moored measurements in the South Atlantic at 34.5°S. The vertical structure of the time-mean flows is consistent with the limited historical observations. Both the upper and abyssal cells exhibit a high degree of variability relative to the temporal means at time scales, ranging from a few days to a few weeks. Observed variations in the abyssal flow appear to be largely independent of the flow in the overlying upper cell. No meaningful trends are detected in either cell.

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Autonomy, Artificial Intelligence, and Telepresence: Advancing Ocean Science at Sea in the COVID-19 Era

Tim Gallaudet, Jamese Sims, Elizabeth Lobecker, Amanda Netburn, Charles Alexander,Kelly Goodwin, and Alexandra Skrivanek. Autonomy, Artificial Intelligence, and Telepresence: Advancing Ocean Science at Sea in the COVID-19 Era. Journal of Ocean Technology, 15(4) 2020

The COVID-19 pandemic has impacted all aspects of society, including seagoing marine science. Social distance measures and quarantine restrictions have required smaller scientific teams and crews on oceanographic ships. Advances in technology offer the potential to continue marine science discovery as the impacts of the pandemic persist. Robotics and uncrewed systems are already widely used in place of in-situ, human-operated systems, while autonomy and artificial intelligence are dramatically increasing the efficiency and effectiveness of nearly every ocean science discipline, including biological observations. Telepresence is a proven capability that can transform any vessel into a virtual international laboratory. We will describe how these tools are applied at the National Oceanic and Atmospheric Administration (NOAA), and how they provide capabilities to move ocean science forward over the course of the COVID-19 pandemic and beyond.

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