Preprints

Filtering by Subject: Oceanography

Energetics and mixing of stratified, rotating flow over abyssal hills

Varvara E Zemskova, Nicolas Grisouard

Published: 2021-07-12
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

One of the proposed mechanisms for energy loss in the ocean is through dissipation of internal waves, in particular above rough topography where internal lee waves are generated. Rates of dissipation and diapycnal mixing are often estimated using linear theory and a constant value for mixing efficiency. However, previous oceanographic measurements found that non-linear dynamics may be important [...]

OpenOBS: Open-source, low-cost optical backscatter sensors for water quality and sediment-transport research

Emily Eidam, Theodore Langhorst, Evan B Goldstein, et al.

Published: 2021-06-17
Subjects: Environmental Monitoring, Fluid Dynamics, Fresh Water Studies, Geomorphology, Oceanography, Sedimentology, Water Resource Management

Optical backscatter sensors (OBSs) are commonly used to measure the turbidity, or light obscuration, of water in fresh and marine environments and various industrial applications. These turbidity measurements are commonly calibrated to yield total suspended solids (TSS) or suspended sediment concentration (SSC) measurements for water quality, sediment transport, and diverse other research and [...]

Matchup Characteristics of Sea Surface Salinity using a High-resolution Ocean Model

Frederick M Bingham, Severine Fournier, Susannah Brodnitz, et al.

Published: 2021-06-16
Subjects: Oceanography

Sea surface salinity (SSS) satellite measurements are validated using in situ observations usually made by surfacing Argo floats. Validation statistics are computed using matched values of SSS from satellites and floats. This study explores how the matchup process is done using a high-resolution numerical ocean model, the MITgcm. One year of model output is sampled as if the Aquarius and Soil [...]

Ubiquity of human-induced changes in climate variability

Keith Bradley Rodgers, Sun-Seon Lee, Nan Rosenbloom, et al.

Published: 2021-06-12
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how climate variability responds to increasing anthropogenic perturbations. Here we present a new 100-member large ensemble of climate change projections conducted with the Community Earth System Model version 2 to examine [...]

Non-deterministic effects in modelling the tidal currents in a high-energy coastal site

Simon Charles Warder, Stephan C Kramer, Matthew D Piggott

Published: 2021-05-27
Subjects: Environmental Sciences, Oceanography

Numerical models are commonly employed for predicting tidal stream resource, since harmonic analysis is typically insufficient for representing tidal currents. This is particularly true in regions of high-energy flow and complex bathymetric and coastline features, resulting in highly nonlinear dynamics. Within this work, we demonstrate that non-deterministic effects pose a further barrier to [...]

CO2 capture by pumping surface acidity to the deep ocean

Michael Tyka, John C Platt, Christopher Van Arsdale

Published: 2021-04-30
Subjects: Chemical Engineering, Climate, Engineering, Environmental Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

The majority of IPCC scenarios call for active CO2 removal (CDR) to remain below 2oC of warm- ing. On geological timescales, ocean uptake regulates atmospheric CO2 concentration, with two homeostats driving CO2 uptake: dissolution of deep ocean calcite deposits and terrestrial weathering of silicate rocks, acting on 1ka to 100ka timescales, respectively. Many current ocean-based CDR proposals [...]

Note on the bulk estimate of the energy dissipation rate in the oceanic bottom boundary layer

Xiaozhou Ruan

Published: 2021-04-26
Subjects: Oceanography, Physical Sciences and Mathematics

The dissipation of the kinetic energy (KE) associated with oceanic flows is believed to occur primarily in the oceanic bottom boundary layer (BBL) where bottom drag converts the KE from mean flows to heat loss through irreversible mixing at molecular scales. Due to the practical difficulties associated with direct observations on small-scale turbulence close to the seafloor, most up-to-date [...]

Optimal experiment design for bottom friction parameter estimation

Simon Charles Warder, Matthew D Piggott

Published: 2021-04-23
Subjects: Design of Experiments and Sample Surveys, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

It is common practice within numerical coastal ocean modelling to perform model calibration with respect to a bottom friction parameter. While many modelling studies employ a spatially uniform coefficient, within the parameter estimation literature the coefficient is typically taken to be spatially (or even temporally) varying. A parameter estimation experiment requires an appropriate set of [...]

A deep-learning estimate of the decadal trends in the Southern Ocean carbon storage

Varvara E Zemskova, Tai-Long He, Zirui Wan, et al.

Published: 2021-04-21
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

Uptake of atmospheric carbon by the ocean, especially at high latitudes, plays an important role in offsetting anthropogenic emissions. At the surface of the Southern Ocean south of 30◦S, the ocean carbon uptake, which had been weakening in 1990s, strengthened in the 2000s. However, sparseness of in-situ measurements in the ocean interior make it difficult to compute changes in carbon storage [...]

A simplified palaeoceanography archiving system (PARIS) and GUI for storage and visualisation of marine sediment core proxy data vs age and depth.

Bryan C. Lougheed, Claire Waelbroeck, Nicolas Smialkowski, et al.

Published: 2021-04-14
Subjects: Climate, Earth Sciences, Oceanography

Scientific discovery can be aided when data is shared following the principles of findability, accessibility, interoperability, reusability (FAIR) data (Wilkinson et al., 2016). Recent discussions in the palaeoclimate literature have focussed on defining the ideal database format for storing data and associated metadata. Here, we highlight an often overlooked primary process in widespread [...]

BENTHIC NUTRIENT FLUXES ACROSS A PRODUCTIVE SHELF ADJACENT TO AN OLIGOTROPHIC BASIN: CASE OF THE NORTHEASTERN MEDITERRANEAN SEA

Ismail Akcay, Suleyman Tugrul, Mustafa Yücel

Published: 2021-04-08
Subjects: Environmental Chemistry, Oceanography

The coastal ecosystem of the Northeastern (NE) Mediterranean has been affected by nutrient inputs originated from regional rivers and wastewater discharges leading to development of eutrophication. Atmospheric nutrient inputs have also remarkable contribution to marine nutrient pool in the NE Mediterranean, especially in dry periods. Sediment porewater nutrient fluxes into the deep waters are [...]

Shallow or deep? A reinterpretation of the Rifian Corridor’s unique sandy contourites

Daan Beelen, Lesli Joy Wood, Mohammed Najib Zaghloul, et al.

Published: 2021-02-25
Subjects: Climate, Earth Sciences, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Paleontology, Sedimentology, Stratigraphy

This study proposes that sandstone layers exposed in the Fez-Meknes region of Northern Morocco (Ben Allou (Sidi Chaded) and El Adergha localities), have been misinterpreted as unique examples of geostrophically-driven, deep marine (150 - 400 m water depth) sandy contourites. Instead, our independent paleontological, sedimentological, and stratigraphic analyses show that these sandstones represent [...]

High-resolution observations of the North Pacific transition layer from a Lagrangian float

Alexis K. Kaminski, Eric A. D'Asaro, Andrey Y. Shcherbina, et al.

Published: 2021-02-11
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

A crucial region of the ocean surface boundary layer (OSBL) is the strongly-sheared and -stratified transition layer (TL) separating the mixed layer from the upper pycnocline, where a diverse range of waves and instabilities are possible. Previous work suggests that these different waves and instabilities will lead to different OSBL behaviours. Therefore, understanding which physical processes [...]

Modeling and SAR Imaging of the Sea Surface: a Review of the State-of-the-Art with Simulations

Igor Rizaev, Oktay Karakus, John Hogan, et al.

Published: 2021-02-10
Subjects: Oceanography

Among other remote sensing technologies, synthetic aperture radar (SAR) has become firmly established in the practice of oceanographic research. Despite solid experience in this field, comprehensive knowledge and interpretation of ocean/sea and vessel wave signatures on radar images are still very challenging. This is not only due to the complex mechanisms involved in the SAR imaging of moving [...]

Dynamical attribution of North Atlantic interdecadal predictability to oceanic and atmospheric turbulence under realistic and optimal stochastic forcing

Dafydd Stephenson, Florian Sévellec

Published: 2021-02-01
Subjects: Climate, Environmental Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

Unpredictable variations in the ocean originate from both external atmospheric forcing and chaotic processes internal to the ocean itself, and are a crucial sink of predictability on interdecadal timescales. In a global ocean model, we present i.) an optimisation framework to compute the most efficient noise patterns to generate uncertainty and ii.) a uniquely inexpensive, dynamical method for [...]

search

You can search by:

  • Title
  • Keywords
  • Author Name
  • Author Affiliation