The surface waves are the most energetic motions, which have great contribution to the turbulent mixing in the upper ocean. In this study, a novel turbulent mixing scheme is proposed in terms of the non‐breaking wave velocity shear module with the buoyancy flux. In the scheme the mixing coefficients can be calculated empirically from the significant wave height (SWH), the wave number, the wave frequency

Hurricane Michael formed on October 7, 2018, in the Northwestern Caribbean Sea, and quickly travelled northward through the Gulf of Mexico, making landfall on the Florida panhandle as a devastating Category 5 hurricane only 3 days later. Before landfall, Michael underwent rapid intensification, despite unfavorable atmospheric conditions. Using observations, we characterized the key ocean features encountered

The Brazil Current, the western limb of the subtropical gyre of the South Atlantic Ocean, is one of the major Western Boundary Currents of the global ocean. Here, we present the first multiyear continuous daily time series of Brazil Current absolute volume transport obtained using 6+ years of observations from a line of four pressure‐recording inverted echo sounders (PIES) deployed at 34.5°S. The array

Over recent decades, the West Antarctic Ice Sheet has experienced rapid thinning of its floating ice shelves as well as grounding line retreat across its marine‐terminating glaciers. The transport of warm Modified Circumpolar Deep Water (MCDW) onto the continental shelf, extensively documented along the West Antarctic Peninsula (WAP), and in the Amundsen Sea, has been identified as the key process

In the eastern Gulf of Guinea (GG), freshwater originated from rivers discharges into the ocean and high precipitation rate are key contributors to the upper ocean vertical density stratification, and play a key role in modulating local air‐sea interactions as well as biogeochemical cycle. Nevertheless, the dynamics of the GG freshwater plumes remain poorly documented because of the scarcity of historical

Increased ocean‐to‐ice heat fluxes play a key role in the accelerated mass loss of Greenland’s marine‐terminating glaciers. Ocean current variability leads to variations in this heat flux. A year‐long time series of ocean currents at all gateways to the ocean cavity under Greenland’s largest remaining floating ice tongue at the Nioghalvfjerdsfjorden Glacier (79NG) was analyzed. The variability of the

A region of exceptionally high macrofaunal benthic biomass exists in Barrow Canyon, implying a carbon export process that is locally concentrated. Here we offer an explanation for this benthic “hotspot” using shipboard data together with a set of dynamical equations. Repeat occupations of the Distributed Biological Observatory transect in Barrow Canyon reveal that when the northward flow is strong

Seabed roughness in the dynamic near‐shore environment is continuously modified by the interplay of physical and biological processes including bedform morphodynamics and bioturbation. We introduce a novel regime‐state framework to determine the dominant modifier of seabed roughness based on observed or estimated physical forcing, which are classified by critical Shields parameter or wave mobility

The Northeast U.S. shelf (NES) is an oceanographically dynamic marine ecosystem and supports some of the most valuable demersal fisheries in the world. A reliable prediction of NES environmental variables, particularly ocean bottom temperature, could lead to a significant improvement in demersal fisheries management. However, the current generation of climate model‐based seasonal‐to‐interannual predictions

We present the δ18O isotope composition of 16 multi‐year ice (MYI) and eight first‐year ice (FYI) cores collected during spring from the Lincoln Sea, a region within the Last Ice Area, which is expected to retain MYI longest into the future. Isotopic signatures were used to quantify the contribution of snow to sea ice mass. These estimates yield a higher total snow contribution in MYI (10 ± 5%) than

Mesoscale eddies redistribute heat, salt, and nutrients in oceans. The South Atlantic Ocean (SA) is a basin that has active mesoscale eddies for which characteristics of the three‐dimensional structure and its leading mechanism are complex but have yet been studied sufficiently. Here based on ocean reanalysis datasets we use a composite analysis approach to analyze the mixed layer anomalous heat budget

Hydrographic data are analyzed for the broad continental shelf of the Bellingshausen Sea, which is host to a number of rapidly‐thinning ice shelves. The flow of warm Circumpolar Deep Water (CDW) onto the continental shelf is observed in the two major glacially‐carved troughs, the Belgica and Latady troughs. Using ship‐based measurements of potential temperature, salinity and dissolved oxygen, collected

A near‐inertial wave stalling and breaking in a critical layer was observed for a week by a pair of autonomous velocity and density profilers on concentric paths in an ocean mesoscale eddy. Profiler observations provide estimates of the eddy's vertical vorticity and shear, quantities needed to test theories of downward near‐inertial wave (NIW) energy flux and loss from inertial wave–eddy interactions

Methane (CH4) is one of the most powerful greenhouse gases with the capacity to influence the Earth's radiative budget as well as contribute to atmospheric chemistry. Natural oceanic production makes up to ∼4% of the overall global CH4 emissions, however, there is uncertainty around the accuracy of this value due to a lack of accurate measurements. Such is the case in the Subtropical Eastern South

The growth and decay mechanisms of barrier layers in the northwestern tropical Atlantic are studied by investigating small‐scale processes embedded in the regional circulation of the tropical Atlantic using output from an eddy‐resolving numerical simulation at 4 km resolution forced by an atmospheric reanalysis. The simulation reproduces well the temporal and spatial patterns of barrier layer thickness

First, we retune an algorithm based on empirical orthogonal functions (EOFs) for globally retrieving the chlorophyll a concentration (Chl‐a) of phytoplankton functional types (PFTs) from multisensor merged ocean color (OC) products. The retuned algorithm, referred to as EOF‐SST hybrid algorithm, is improved by: (i) using 23% more matchups between the updated global in situ pigment database and satellite

Most estuaries are characterized by non‐uniform axial topography with shallow shoals near the mouth. Previous studies have addressed the impacts of the axial topographic variations on mixing and estuarine circulations yet seldom on material transport and retention. This study investigates the longitudinal structure and mechanisms of exchange flow and material transport of Chesapeake Bay (CB), featuring

Intensive air‐sea interaction and the formation of the salinity barrier layer (BL) in the Pacific has fundamental importance to the El Niño evolution. The structure and formation of the BL in the equatorial Pacific Ocean during moderate and extreme El Niños over the past 30 years are investigated using in situ temperature and salinity data measured by the TAO/TRITON array and the data‐assimilating

Photosynthesis‐irradiance (P‐E) parameters, such as the maximum photosynthetic rate () and maximum light utilization coefficient (α), are key parameters of primary production (PP) models. It is necessary to understand the response of P‐E parameters to mesoscale eddies to accurately model PP in eddies. The P‐E parameters and phytoplankton communities were examined at the surface and the deep chlorophyll

We formulate an expression for the turbulent kinetic energy dissipation rate, ϵ, associated with shear‐generated turbulence in terms of quantities in the ocean or atmosphere that, depending on the situation, may be measurable or resolved in models. The expression depends on the turbulent vertical length scale, ℓv, the inverse time scale N, and the Richardson number Ri = N2/S2, where S is the vertical

This study describes biweekly (defined as periods between 10 and 15 days) ocean variability in relation to equatorial wave theory using a comprehensive set of moored ocean current velocities as well as satellite‐retrieved oceanic and atmospheric parameters in the Indian Ocean. Moored biweekly current velocities exhibit the meridional structure of mixed Rossby‐gravity waves: Symmetric for meridional

The objective of this research was to analyze the progression of breaker types on plane impermeable slopes. This study used dimensional analysis to demonstrate the relative water depth is a key explanatory quantity. The dominant breaker types depend on the incident wave characteristics at the foot of the slope. Accordingly, it is possible to combine values of H, T, and m. The physical experiments of

Seasonal modulation of the M2 tide has been quantified for the entire Arctic Ocean and connected regional seas, using tidal harmonic analysis of water levels derived from Synthetic Aperture Radar altimetry. Results are compared to numerical simulations that model the effect of two limiting cases of seasonal landfast ice cover on the M2 tide. The largest seasonal modulation (up to 0.25 m) is observed

We explored how algorithm (model) and in situ measurement (observation) uncertainties can effectively be incorporated into empirical ocean color model development and assessment. In this study we focused on methods for deriving the particulate backscattering coefficient at 555 nm, bbp(555) (m−1). We developed a simple empirical algorithm for deriving bbp(555) as a function of a remote sensing reflectance

The western boundary current in the equatorial Atlantic Ocean is a main conduit for water‐mass exchanges across the equator and thus a major pathway for the interhemispheric transports in the Atlantic Meridional Overturning Circulation (AMOC) system. In this study we quantify and examine the mean and seasonal variability of the equatorial western boundary current (EWBC) in the upper ocean layer using

We use a 30‐year time series (1986–2016) of dichlorodifluoromethane (CFC‐12) concentrations with a refined transit time distribution (TTD) method, to estimate the temporal variation of anthropogenic carbon (Cant) in the Central Labrador Sea. We determined that the saturation of CFC‐12 and sulfur hexafluroide (SF6) in newly‐formed Labrador Sea Water had departed significantly from 100% and varied systematically

Mechanisms controlling the heat budget of the North Sea are investigated based on a combination of satellite sea surface temperature measurements and numerical model simulations. Lateral heat fluxes across the shelf edge and into the Baltic Sea as well as vertical ocean‐atmosphere heat exchange are considered. A 3‐D variational (3DVAR) data assimilation (DA) scheme is applied, which contains assumed

Quantifying and understanding the processes driving turbulent mixing around Antarctica are key to closing the Southern Ocean's heat budget, an essential component of the global climate system. In 2016, a glider deployed in Ryder Bay, West Antarctic Peninsula, collected hydrographic and microstructure data, obtaining some of the first direct measurements of turbulent kinetic energy dissipation off West

A 57‐days record of surface currents observed from high‐frequency radars on the Chinese coast, along with wind records, are analyzed to investigate wintertime variability of surface currents in the southwestern Taiwan Strait. The M2 tide dominates tidal variability, and the semimajor axes of semidiurnal tidal current ellipses coincide well with bathymetry contours suggesting interactions with a propagating

From late‐summer 2013 to late‐summer 2014, a total of 20 moorings were maintained on the eastern Chukchi Sea shelf as part of five independent field programs. This provided the opportunity to analyze an extensive set of timeseries to obtain a broad view of the mean and seasonally‐varying hydrography and circulation over the course of the year. Year‐long mean bottom temperatures reflected the presence

An estuarine turbidity maximum (ETM) is a region of elevated suspended sediment concentration (SSC) resulting from residual transport mechanisms driven by river flow, tides, and salinity‐induced density gradients (SalDG). However, in energetic and highly turbid environments such as the Yangtze Estuary, sediment‐induced density gradients (SedDG) may also substantially contribute to the formation and

A regional coupled sea ice‐ocean model and mooring/shipboard measurements are used to investigate the origins, seasonality, and downstream fate the Chukchi Slope Current. Three years (2013‐2015) of model integration indicates that, in the mean, the model slope current transports approximately 0.45 Sv of Pacific water northwestward along the Chukchi continental slope. Only 62% of this water emanates

The Great Lakes’ atmosphere predominantly signposts signatures of climate change in terms of an elongated summer, depletion of ice‐cover, and up‐surging lake surface temperature and air temperature, which demands an in‐depth comprehension of future lake circulation dynamics. After satisfactory validations for the lake meteorology and hydrodynamics during 2010‐2019, historical and future predictions

Over the core region of the Agulhas Current, new estimations of ocean surface velocities are reported using the increasing dataset from the Automatic Identification System (AIS), initially designed to monitor vessel traffic. A two‐step strategy is suggested. A first guess is evaluated from the collective behavior of vessels for a given space‐time interval. Individual vessel trajectories are then re‐analyzed

Global warming may modify submesoscale activity in the ocean through changes in the mixed layer depth (MLD) and lateral buoyancy gradients. As a case study we consider a region in the NE Atlantic under present and future climate conditions, using a time‐slice method and global and nested regional ocean models. The high resolution regional model reproduces the strong seasonal cycle in submesoscale activity

Internal tides are energetic in the Mariana arc, but their three‐dimensional radiation and dissipation remain unexplored, particularly the trench‐arc‐basin impacts. Here, the generation, propagation and dissipation of M2 internal tides over the Mariana area are examined using a series of observation‐supported high‐resolution simulations. The M2 barotropic to baroclinic conversion rate amounts to 8

Climate and human pressures can influence the evolution of estuarine sediment dynamics concurrently, but the understanding and quantification of their cause–effect relationships are still challenging due to the occurrence of complex hydro‐morpho‐sedimentary feedbacks. The Garonne Tidal River (GTR, upper Gironde Estuary, France) is a clear example of a system stressed by both anthropogenic and climate

Earlier studies in the Northeast Pacific (NEP) suggest that the local and remote sea level responses are important for the large‐scale, low‐frequency sea level variability, but the relative importance of the two processes remains unclear. In this study, we develop a novel sea level model driven by wind, buoyancy and eddy forcing to examine their relative roles in the NEP. Based on the new model, a

An extraordinary strong wind‐driven upwelling event occurred in Lake Superior in summer of 2010 when the lake was strongly stratified. In this paper, a detailed three‐dimensional (3‐D) investigation of the current and thermal structures during the upwelling event was conducted using in situ observations, remote sensing products, and the results of a long‐term numerical simulation. A 3‐D finite‐volume

In frontal zones, water masses that are tens of kilometers in extent with origins in the mixed layer can be identified in the pycnocline for days to months. Here, we explore the pathways and mechanisms of subduction, the process by which water from the surface mixed layer makes its way into the pycnocline, using a submesoscale‐resolving numerical model of a mesoscale front. By identifying Lagrangian

We combine archival research, semi‐analytical models, and numerical simulations to address the following question: how do changes to channel geometry alter tidal properties and flood dynamics in a hyposynchronous, strongly frictional estuary with a landward decay in tidal amplitudes? Records in the Saint Johns River Estuary since the 1890s show that tidal range has doubled in Jacksonville, Florida

The tides in the Kitikmeot Sea, in the southern Canadian Arctic Archipelago, are found to be heavily influenced by seasonal sea‐ice formation and blocking in a strait. Data from a moored current profiler in Dease Strait exhibit strong tidal damping during wintertime seasonal sea‐ice cover, with 50%–60% reduction in tidal elevation and 65% reduction in tidal velocities. We used a 3D unstratified barotropic

The bottom friction coefficient (BFC) is critical for precisely determining hydrodynamic conditions and sediment transport rates, which are important for scientific research and coastal ocean engineering. The BFC varies spatially and temporally, as indicated by in situ observations, but it is difficult to accurately set this parameter in tidal models. In this study, based on a two‐dimensional multi‐constituent

The conventional use of optically determined 1% of surface photosynthetically available radiation (PAR) depth (Z1%PAR, λ = 400–700 nm) as a metric for the euphotic zone depth (Zeu) has been a matter of debate for several decades because of frequent inconsistencies with the base of euphotic zone determined biologically, that is, the compensation depth (Zc). In this study, we attempt to reconcile between

Variations in the mass and heat transported by the meridional overturning circulation (MOC) have important, well‐documented, influences on global and regional climate, weather, ecosystems, and coastal sea levels. However, continuous, high‐frequency, observations of these quantities have been limited to date. Multiple years of full‐depth daily observations from moored instruments in the South Atlantic

Hypoxia has been observed worldwide and causes great damage to marine ecosystems. In the northeastern mariculture areas of the Shandong Peninsula, summer oxygen depletion and even hypoxia have been observed in the bottom layer, but the underlying dynamics are still poorly understood. In the current study, the physical controls of variations in bottom layer oxygen concentrations in summer and their

Eddies in the Western Arctic play an important role in transporting heat, salt, and biogeochemical tracers across the continental shelf and within the deep basins. However, comprehensive observations of the regional and temporal variability of the eddy field characteristics are difficult to obtain remotely due to the presence of sea ice, and the available in situ observations remain relatively sparse

We performed laboratory experiments to investigate the influence of sand content on the dynamics of wave‐supported gravity flows in mud‐dominant environments. The experiments were carried out in an oscillatory water tunnel with a sediment bed of either 1% or 13% sand. Low and high energy regimes are differentiated based on a Stokes Reynolds number ReΔ ≈ 500. In the low energy regime, the sand fraction

Although most tsunamis are generated by the sea‐bottom deformation caused by earthquakes, some tsunamis are excited by sea‐surface pressure changes. This study theoretically investigated tsunamis generated by sea‐surface pressure changes and derived the solutions in 3‐D space, whereas most past studies employed 2‐D equations. Using the solutions, we simulated and visualized the tsunami generation by

No abstract is available for this article.

X‐band radar observations from the 2017 Inner Shelf Dynamics Experiment (ISDE) in central California show multiple persistent and pulsatory rip currents on a relatively straight coastline with alongshore‐varying bathymetry. Although past studies have assessed the characteristics of transient rip currents on alongshore uniform beaches, the relative balance of transient versus steady rip current behavior

Saharan dust outbreaks frequently propagate westward over the Atlantic Ocean; accurate quantification of the dust aerosol scattering and absorption effect on the surface radiative fluxes (SRF) is fundamental to understanding critical climate feedbacks. By exploiting large sets of measurements from many ship campaigns in conjunction with reanalysis products, this study characterizes the sensitivity

In the Indian Ocean, salty water masses from the Persian Gulf and Red Sea are important sources of salt, heat, and nutrients. Across the Arabian Sea, these outflows impact human and biological activities, their thermohaline characteristics and shapes exhibiting important spatial and seasonal variability. The knowledge of the water masses properties is important to validate realistic simulations of

It is well known that climate and circulation model simulation output are often systematically biased. However, existing bias correction methods typically ignore spatial autocorrelation of the biases and correct only the overall mean and variance, resulting in mismatched spatial variability between bias‐corrected simulations and observations. In this study, we propose using regression kriging (RK)

East Asian Marginal Seas are a continuum receiving multiple large rivers including the Changjiang, the Yellow, and the Pearl Rivers. Fates of these river discharges are strongly influenced by the energetic shelf circulation system. Meanwhile, the massive freshwater discharge from these rivers also modulate the density structure and dynamic height of receiving seas, which could affect the shelf circulation

We revisited the partitioning of the Mediterranean Sea into bioregions by processing satellite Sea Surface Temperature (SST) and Chlorophyll‐a concentration (Chla) from ocean color observations combined with Argo mixed‐layer depth for a period ranging from 2003 up to 2020. This regionalization was performed using an innovative classification based on self‐organizing maps, the so‐called 2S‐SOM. We clustered

A high‐resolution ocean model is used to characterize the circulation and cross‐shelf exchanges in the Brazilian/Uruguayan portion of the southwestern Atlantic shelf. Cross‐shelf exchanges are strongly modulated by the bottom topography. There is ∼1.2Sv of onshelf transport between 21°S and 25.2°S, and ∼1.6Sv of offshelf transport between 35°S and 25.2°S. North of 25.2°S the cross‐shelf exchanges show

Sediment dynamics have great effects on the morphology of estuaries and deltas. As riverine sediment input has decreased in many estuaries in recent years, the removal and dispersion of sediments by currents and waves inside estuaries has assumed a more dominant role; however, the overall effects of waves are less well understood. In this study, we used the Coupled Ocean Atmosphere Wave Sediment Transport

Horizontal and vertical motions associated with mesoscale (10–100 km) and submesoscale (1–10 km) features, such as fronts, meanders, eddies, and filaments, play a critical role in redistributing physical and biogeochemical properties in the ocean. This study makes use of a multiplatform data set of 82 drifters, a Lagrangian float, and profile timeseries of temperature and salinity, obtained in a ∼1‐m/s

Turbulent mixing driven by internal tides (ITs) in the ocean is essential for the maintenance of large‐scale circulation. The resonant triad interaction (RTI) is an important mechanism by which ITs are dissipated. Based on a series of numerical simulations, we show that background geostrophic currents (BGCs) with nonzero vertical relative vorticity significantly impact the RTI by changing the effective