Preprints
Filtering by Subject: Oceanography
Wide-swath altimetric satellite data assimilation with structured-error detrending
Published: 2019-09-18
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
For decades now, satellite altimetric observations have been successfully integrated in numerical oceanographic models using data assimilation (DA). So far, sea surface height (SSH) data were provided by one-dimensional nadir altimeters. The next generation Surface Water and Ocean Topography (SWOT) satellite altimeter will provide two-dimensional wide-swath altimetric information with an [...]
Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years
Published: 2019-09-06
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
High latitude deep water upwelling has the potential to control global climate over glacial timescales through the biological pump and ocean-atmosphere CO2 exchange. However, there is currently a lack of continuous long nutrient upwelling records with which to assess this mechanism. Here we present geochemical proxy records for nutrient upwelling and glacial North Pacific Intermediate Water [...]
Quantifying Eulerian Eddy Leakiness in An Idealized Model
Published: 2019-08-21
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An idealized eddy-resolving ocean basin, closely resembling the North Pacific ocean, is simulated using MITgcm. We identify rotationally coherent Lagrangian vortices (RCLVs) and sea surface height (SSH) eddies based on the Lagrangian and Eulerian framework, respectively. General statistical results show that RCLVs have a much smaller coherent core than SSH eddies with the ratio of radius is about [...]
Vertical Eddy Iron Fluxes Support Primary Production in the Open Southern Ocean
Published: 2019-08-04
Subjects: Biogeochemistry, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The primary productivity of the Southern Ocean ecosystem, and associated biological carbon pump, is limited by the availability of the micronutrient iron. Riverine sediments and atmospheric dust supply iron at the ocean margins, but in the vast open ocean, iron reaches phytoplankton primarily when iron-rich sub-surface waters enter the euphotic zone, linking vertical transport processes to [...]
The contribution of submesoscale over mesoscale eddy iron transport in the open Southern Ocean
Published: 2019-07-18
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In order to examine the roles of ocean dynamics in supplying iron, the limiting nutrient in the open Southern Ocean, to the surface where it can be effectively utilized for photosynthesis, we run a flat-bottom zonally re-entrant channel model configured to represent the Antarctic Circumpolar Current region and couple it to a full biogeochemical model. The model was forced with monthly varying [...]
Can barrier islands survive sea-level rise? Quantifying the relative role of tidal deltas and overwash deposition
Published: 2019-07-18
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accepted open-access publication available at: https://doi.org/10.1029/2019GL085524 Barrier island response to sea-level rise depends on their ability to transgress and move sediment onto and behind the barrier, either through flood-tidal delta deposition, or via overwash. Our understanding of these processes over decadal or longer timescales, however, is limited. Here we [...]
Southern Ocean Phytoplankton Blooms Observed by Biogeochemical Floats
Published: 2019-07-17
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics
The spring bloom in the Southern Ocean is the rapid-growth phase of the seasonal cycle in phytoplankton. Many previous studies have characterized the spring bloom using chlorophyll estimates from satellite ocean color observations. Assumptions regarding the chlorophyll-to-carbon ratio within phytoplankton and vertical structure of biogeochemical variables lead to uncertainty in satellite-based [...]
Heat distribution in the Southeast Pacific is only weakly sensitive to high-latitude heat flux and wind stress
Published: 2019-07-16
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Southern Ocean features regionally-varying ventilation pathways that transport heat and carbon from the surface ocean to the interior thermocline on timescales of decades to centuries, but the factors that control the distribution of heat along these pathways are not well understood. In this study, we use a global ocean state estimate (ECCOv4) to (1) define the recently ventilated interior [...]
The sensitivity of Southeast Pacific heat distribution to local and remote changes in ocean properties
Published: 2019-07-16
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Southern Ocean features ventilation pathways that transport surface waters into the subsurface thermocline on timescales of decades to centuries, sequestering anomalies of heat and carbon away from the atmosphere and thereby regulating the rate of surface warming. Despite its importance for climate sensitivity, the factors that control the distribution of heat along these pathways are not [...]
Probing the chemical transformation of seawater-soluble crude oil components during microbial oxidation
Published: 2019-06-18
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Chemistry, Environmental Sciences, Life Sciences, Microbiology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics
Studies assessing the environmental impacts of oil spills focus primarily on the non-water-soluble components, leaving the fate of the water-soluble fraction (WSF) largely unexplored. We employed untargeted chemical analysis along with biological information to probe the transformation of crude oil WSF in seawater, in the absence of light, in a laboratory experiment. Over a 14-day incubation, [...]
On the automatic and a priori design of unstructured mesh resolution for coastal ocean circulation models
Published: 2019-05-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Civil and Environmental Engineering, Other Earth Sciences, Physical Sciences and Mathematics
This study investigates the design of unstructured mesh resolution and its impact on the modeling of barotropic tides along the United States East Coast and Gulf Coast (ECGC). A discrete representation of a computational ocean domain (mesh design) is necessary due to finite computational resources and an incomplete knowledge of the physical system (e.g., shoreline and seabed topography). The [...]
Reduction of spatially structured errors in wide-swath altimetric satellite data using data assimilation
Published: 2019-05-08
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Surface Water and Ocean Topography (SWOT) mission is a next generation satellite mission expected to provide a 2km-resolution observation of the sea surface height (SSH) on a two-dimensional swath. Processing SWOT data will be challenging, because of the large amount of data, the mismatch between high spatial resolution and low temporal resolution, and the observation errors. The present [...]
The flow of fresh groundwater and solutes to the world’s oceans and coastal ecosystems
Published: 2019-03-31
Subjects: Earth Sciences, Hydrology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The flow of fresh groundwater towards the world oceans may provide substantial inputs of nutrients and solutes to the oceans. Here we present a spatially resolved global model of coastal groundwater discharge to show that the contribution of fresh groundwater is lower than most previous estimates and accounts for only ~0.6% of the freshwater input and ~2% of the solute input to the oceans. [...]
New flow relaxation mechanism explains scour fields at the end of submarine channels
Published: 2019-03-11
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
In the ocean, particle-laden gravity flows, turbidity currents, flow in river-like channels across the ocean floor. These submarine channels funnel sediment, nutrients, pollutants and organic carbon into the ocean basins and can extend over 1,000’s of kilometers. At the end of these channels, turbidity currents lose their confinement, decelerate and deposit their sediment load. This is what we [...]
Factor Analysis by R Programming to Assess Variability Among Environmental Determinants of the Mariana Trench
Published: 2019-01-28
Subjects: Computer Sciences, Earth Sciences, Education, Engineering, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Graphics and Human Computer Interfaces, Life Sciences, Marine Biology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Geography, Other Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Programming Languages and Compilers, Remote Sensing, Science and Mathematics Education, Sedimentology, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure, Water Resource Management
The aim of this work is to identify main impact factors affecting variations in the geomorphology of the Mariana Trench which is the deepest place of the Earth, located in the west Pacific Ocean: steepness angle and structure of the sediment compression. The Mariana Trench presents a complex ecosystem with highly interconnected factors: geology (sediment thickness and tectonics including four [...]