INCORPORATION OF CONTINENTAL AND URBAN RUN-OFF INTO A COASTAL CIRCULATION MODEL: APPLICATION TO THE CATALAN COAST

A 3D hydrodynamical model has been set up to incorporate the continental and urban run-off into the Catalan Coastal waters. Particular attention was paid to introducing correctly the freshwater plumes and attention was also paid to determinate the influence of the land discharge profile with regard to the distributed continental run-off. The model domain includes a small part of the Catalan Coast where the combination of local land topography with torrential rainfall caused considerable local runoff on a short period of time with a large impact on the receiving coastal waters. The Regional Ocean Modeling System (ROMS) simulations were used to examine the dispersal to a freshwater delivery from two relevant event; a low river discharge typical of mean conditions during April 2011 and a high discharge representative of the storm event during March 2011 are considered. We have observed the plume responses to an abrupt change in river discharge. During the mean conditions, low salinity water is concentrated around the rivers mouth while during the flood event, the plume spread offshore in the direction of river water outflow and turned downstream close to the coast. The differences between a simulation including the river outflow as a land forcing and a simulation including river and urban runoff as a land forcing suggested that the urban runoff plays an important role in the spreading and shape of the river plume.

Download Full-text

Dynamics of the Block Island Sound Estuarine Plume

Journal of Physical Oceanography ◽

10.1175/jpo-d-15-0099.1 ◽

2016 ◽

Vol 46 (5) ◽

pp. 1633-1656 ◽

Cited By ~ 4

Author(s):

Qianqian Liu ◽

Lewis M. Rothstein ◽

Yiyong Luo

Keyword(s):

Seasonal Variation ◽

River Discharge ◽

Long Island ◽

Long Island Sound ◽

Ocean Modeling ◽

Surface Heating ◽

Buoyant Plume ◽

Regional Ocean Modeling System ◽

Block Island ◽

Island Sound

AbstractBuoyant discharge of freshwater from Long Island Sound (LIS) forms a seasonal buoyant plume outside Block Island Sound (BIS) between the coast of Long Island and the denser shelf waters. The plume’s seasonal variability and its response to tides, winds, and surface heating are investigated through a series of process-oriented experiments using the Regional Ocean Modeling System (ROMS). Results show the importance of river discharge, wind directions, and surface heating in the seasonal variation of the BIS buoyant plume. In winter and spring, the plume is intermediate with a large surface offshore extension detached from the bottom. From winter to spring, the river discharge increases; meanwhile, upwelling-favorable winds keep dominating. They compete with the increase of surface heating and generate a broader buoyant plume in spring than in winter. In summer, the plume is bottom advected with most of its width in contact with the bottom and is featured with the steepest isopycnals and narrowest plume, which is driven by a combination of strong insolation, weak buoyant discharge from LIS, and feeble winds. In fall, although the river discharge is comparable to that in winter, the upwelling-favorable wind is relatively weaker, corresponding to a narrower intermediate plume.

Download Full-text

High-Resolution Operational Ocean Forecast and Reanalysis System for the Indian Ocean

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-19-0083.1 ◽

2020 ◽

Vol 101 (8) ◽

pp. E1340-E1356 ◽

Cited By ~ 1

Author(s):

P. A. Francis ◽

A. K. Jithin ◽

J. B. Effy ◽

A. Chatterjee ◽

K. Chakraborty ◽

...

Keyword(s):

High Resolution ◽

Indian Ocean ◽

Data Assimilation ◽

Coastal Waters ◽

General Circulation ◽

High Performance ◽

Coast Guard ◽

Ocean Modeling ◽

Regional Ocean Modeling System ◽

The Indian Ocean

Abstract A good understanding of the general circulation features of the oceans, particularly of the coastal waters, and ability to predict the key oceanographic parameters with good accuracy and sufficient lead time are necessary for the safe conduct of maritime activities such as fishing, shipping, and offshore industries. Considering these requirements and buoyed by the advancements in the field of ocean modeling, data assimilation, and ocean observation networks along with the availability of the high-performance computational facility in India, Indian National Centre for Ocean Information Services has set up a “High-Resolution Operational Ocean Forecast and Reanalysis System” (HOOFS) with an aim to provide accurate ocean analysis and forecasts for the public, researchers, and other types of users like navigators and the Indian Coast Guard. Major components of HOOFS are (i) a suite of numerical ocean models configured for the Indian Ocean and the coastal waters using the Regional Ocean Modeling System (ROMS) for forecasting physical and biogeochemical state of the ocean and (ii) the data assimilation based on local ensemble transform Kalman filter that assimilates in situ and satellite observations in ROMS. Apart from the routine forecasts of key oceanographic parameters, a few important applications such as (i) Potential Fishing Zone forecasting system and (ii) Search and Rescue Aid Tool are also developed as part of the HOOFS project. The architecture of HOOFS, an account of the quality of ocean analysis and forecasts produced by it and important applications developed based on HOOFS are briefly discussed in this article.

Download Full-text

Linear Wind-Forced Beta Plumes with Application to the Hawaiian Lee Countercurrent*

Journal of Physical Oceanography ◽

10.1175/jpo-d-12-0194.1 ◽

2013 ◽

Vol 43 (10) ◽

pp. 2071-2094 ◽

Cited By ~ 11

Author(s):

Ali Belmadani ◽

Nikolai A. Maximenko ◽

Julian P. Mccreary ◽

Ryo Furue ◽

Oleg V. Melnichenko ◽

...

Keyword(s):

General Circulation Model ◽

General Circulation ◽

Circulation Model ◽

Ocean Modeling ◽

North Equatorial Current ◽

Regional Ocean Modeling System ◽

The West ◽

Near Surface ◽

Zonal Jets ◽

Hawaiian Lee Countercurrent

Abstract Two numerical ocean models are used to study the baroclinic response to forcing by localized wind stress curl (i.e., a wind-forced β plume, which is a circulation cell developing to the west of the source region and composed of a set of zonal jets) with implications for the Hawaiian Lee Countercurrent (HLCC): an idealized primitive equation model [Regional Ocean Modeling System (ROMS)], and a global, eddy-resolving, general circulation model [Ocean General Circulation Model for the Earth Simulator (OFES)]. In addition, theoretical ideas inferred from a linear continuously stratified model are used to interpret results. In ROMS, vertical mixing preferentially damps higher-order vertical modes. The damping thickens the plume to the west of the forcing region, weakening the near-surface zonal jets and generating deeper zonal currents. The zonal damping scale increases monotonically with the meridional forcing scale, indicating a dominant role of vertical viscosity over diffusion, a consequence of the small forcing scale. In the OFES run forced by NCEP reanalysis winds, the HLCC has a vertical structure consistent with that of idealized β plumes simulated by ROMS, once the contribution of the North Equatorial Current (NEC) has been removed. Without this filtering, a deep HLCC branch appears artificially separated from the surface branch by the large-scale intermediate-depth NEC. The surface HLCC in two different OFES runs exhibits sensitivity to the meridional wind curl scale that agrees with the dynamics of a β plume in the presence of vertical viscosity. The existence of a deep HLCC extension is also suggested by velocities of Argo floats.

Download Full-text

Doppio – a ROMS (v3.6)-based circulation model for the Mid-Atlantic Bight and Gulf of Maine: configuration and comparison to integrated coastal observing network observations

Geoscientific Model Development ◽

10.5194/gmd-13-3709-2020 ◽

2020 ◽

Vol 13 (8) ◽

pp. 3709-3729 ◽

Cited By ~ 3

Author(s):

Alexander G. López ◽

John L. Wilkin ◽

Julia C. Levin

Keyword(s):

Gulf Of Maine ◽

Circulation Model ◽

Surface Current ◽

Ocean Modeling ◽

Skill Assessment ◽

Dynamic Topography ◽

Error Statistics ◽

Regional Ocean Modeling System ◽

Data Set ◽

Current Measuring

Abstract. We describe “Doppio”, a ROMS-based (Regional Ocean Modeling System) model of the Mid-Atlantic Bight and Gulf of Maine regions of the northwestern North Atlantic developed in anticipation of future applications to biogeochemical cycling, ecosystems, estuarine downscaling, and near-real-time forecasting. This free-running regional model is introduced with circulation simulations covering 2007–2017. The ROMS configuration choices for the model are detailed, and the forcing and boundary data choices are described and explained. A comprehensive observational data set is compiled for skill assessment from satellites and in situ observations from regional associations of the U.S. Integrated Ocean Observing Systems, including moorings, autonomous gliders, profiling floats, surface-current-measuring coastal radar, and fishing fleet sensors. Doppio's performance is evaluated with respect to these observations by representation of subregional temperature and salinity error statistics, as well as velocity and sea level coherence spectra. Model circulation for the Mid-Atlantic Bight and Gulf of Maine is visualized alongside the mean dynamic topography to convey the model's capabilities.

Download Full-text

Combining gliders and models to understand mesoscale biogeochemical patterns at the Angola-Benguela front

10.5194/egusphere-egu21-8494 ◽

2021 ◽

Author(s):

Elisa Lovecchio ◽

Stephanie Henson ◽

Filipa Carvalho ◽

Nathan Briggs

Keyword(s):

Organic Carbon ◽

Circulation Model ◽

Biological Data ◽

Ocean Modeling ◽

Biogeochemical Model ◽

Identification Algorithm ◽

Low Oxygen ◽

The South ◽

Regional Ocean Modeling System ◽

Wide Range

<p>The Angola-Benguela frontal region represents an extremely dynamic portion of the ocean located along the south-western African coast, at the northern edge of the South Atlantic gyre. At this boundary, the northern warm and saline waters of the Angola Basin mix with the southern colder and fresher waters carried by the Benguela current through a combination of processes that span a wide range of spatio-temporal scales. This study combines the use of underwater glider data collected between February and June 2018 with a high resolution 3D physical-biogeochemical model to investigate how these lateral exchanges impact the oxygen and organic carbon distributions in the proximity of the front. From the glider data, we identify a set of salinity, oxygen and organic carbon anomalies impacting the first 500 m of the water column during February-June 2018. Using satellite images of physical and biological data and an eddy identification algorithm, we discuss these anomalies in the context of the surrounding physical and biological setting at the time of measurement and identify key processes that may be responsible for the observed tracer patterns. We employ the Regional Ocean Modeling System (ROMS) coupled with the Biogeochemistry Ecosystem Circulation model (BEC) to further explain and upscale our findings. We study the dynamics of cross-frontal exchanges of oxygen and organic carbon in the first 500 m depth. We show how the coupling between long filaments and intense anticyclonic eddies forming at the front generates a complex pattern of recirculation of Angola Basin-derived saline and low-oxygen waters into the oxygenated Benguela region. Finally, we quantify the oxygen lateral transport coupled with these dynamics, and discuss the implications for the biological activity in the region.</p>

Download Full-text

The Inverse Ocean Modeling System. Part II: Applications

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2008jtecho522.1 ◽

2008 ◽

Vol 25 (9) ◽

pp. 1623-1637 ◽

Cited By ~ 18

Author(s):

J. C. Muccino ◽

H. Luo ◽

H. G. Arango ◽

D. Haidvogel ◽

J. C. Levin ◽

...

Keyword(s):

Three Dimensional ◽

Circulation Model ◽

Spectral Element ◽

Ocean Model ◽

Ocean Modeling ◽

Primitive Equations ◽

Modular System ◽

Regional Ocean Modeling System ◽

System Part ◽

Scientific Phenomena

Abstract The Inverse Ocean Modeling (IOM) System is a modular system for constructing and running weak-constraint four-dimensional variational data assimilation (W4DVAR) for any linear or nonlinear functionally smooth dynamical model and observing array. The IOM has been applied to four ocean models with widely varying characteristics. The Primitive Equations Z-coordinate-Harmonic Analysis of Tides (PEZ-HAT) and the Regional Ocean Modeling System (ROMS) are three-dimensional, primitive equations models while the Advanced Circulation model in 2D (ADCIRC-2D) and Spectral Element Ocean Model in 2D (SEOM-2D) are shallow-water models belonging to the general finite-element family. These models, in conjunction with the IOM, have been used to investigate a wide variety of scientific phenomena including tidal, mesoscale, and wind-driven circulation. In all cases, the assimilation of data using the IOM provides a better estimate of the ocean state than the model alone.

Download Full-text