scholarly journals Multi-Platform, High-Resolution Study of a Complex Coastal System: The TOSCA Experiment in the Gulf of Trieste

2021 ◽  
Vol 9 (5) ◽  
pp. 469
Author(s):  
Stefano Querin ◽  
Simone Cosoli ◽  
Riccardo Gerin ◽  
Célia Laurent ◽  
Vlado Malačič ◽  
...  
Keyword(s):  
High Resolution ◽  
General Circulation ◽  
Large Scale ◽  
Adriatic Sea ◽  
Circulation Model ◽  
Discharge Data ◽  
Coastal System ◽  
Northern Adriatic ◽  
Gulf Of Trieste ◽  
Lagrangian Drifter

Although small in size, the Gulf of Trieste (GoT), a marginal coastal basin in the northern Adriatic Sea, is characterized by very complex dynamics and strong variability of its oceanographic conditions. In April–May 2012, a persistent, large-scale anticyclonic eddy was observed in the GoT. This event was captured by both High Frequency Radar (HFR) and Lagrangian drifter observations collected within the European MED TOSCA (Tracking Oil Spill and Coastal Awareness) project. The complexity of the system and the variety of forcing factors constitute major challenges from a numerical modeling perspective when it comes to simulating the observed features. In this study, we implemented a high-resolution hydrodynamic model in an attempt to reproduce and analyze the observed basin-wide eddy structure and determine its drivers. We adopted the Massachusetts Institute of Technology General Circulation Model (MITgcm), tailored for the GoT, nested into a large-scale simulation of the Adriatic Sea and driven by a tidal model, measured river freshwater discharge data and surface atmospheric forcing. Numerical results were qualitatively and quantitatively evaluated against HFR surface current maps, Lagrangian drifter trajectories and thermohaline data, showing good skills in reproducing the general circulation, but failing in accurately tracking the drifters. Model sensitivity to different forcing factors (wind, river and tides) was also assessed.

scholarly journals Effects of Tropical Cyclones on Ocean Heat Transport in a High-Resolution Coupled General Circulation Model

2011 ◽  
Vol 24 (16) ◽  
pp. 4368-4384 ◽  
Author(s):  
Enrico Scoccimarro ◽  
Silvio Gualdi ◽  
Alessio Bellucci ◽  
Antonella Sanna ◽  
Pier Giuseppe Fogli ◽  
...  
Keyword(s):  
Twentieth Century ◽  
High Resolution ◽  
Heat Transport ◽  
Tropical Cyclones ◽  
General Circulation Model ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Ocean Heat Transport ◽  
Coupled General Circulation Model

Abstract In this paper the interplay between tropical cyclones (TCs) and the Northern Hemispheric ocean heat transport (OHT) is investigated. In particular, results from a numerical simulation of the twentieth-century and twenty-first-century climates, following the Intergovernmental Panel on Climate Change (IPCC) twentieth-century run (20C3M) and A1B scenario protocols, respectively, have been analyzed. The numerical simulations have been performed using a state-of-the-art global atmosphere–ocean–sea ice coupled general circulation model (CGCM) with relatively high-resolution (T159) in the atmosphere. The CGCM skill in reproducing a realistic TC climatology has been assessed by comparing the model results from the simulation of the twentieth century with available observations. The model simulates tropical cyclone–like vortices with many features similar to the observed TCs. Specifically, the simulated TCs exhibit realistic structure, geographical distribution, and interannual variability, indicating that the model is able to capture the basic mechanisms linking the TC activity with the large-scale circulation. The cooling of the surface ocean observed in correspondence of the TCs is well simulated by the model. TC activity is shown to significantly increase the poleward OHT out of the tropics and decrease the poleward OHT from the deep tropics on short time scales. This effect, investigated by looking at the 100 most intense Northern Hemisphere TCs, is strongly correlated with the TC-induced momentum flux at the ocean surface, where the winds associated with the TCs significantly weaken (strengthen) the trade winds in the 5°–18°N (18°–30°N) latitude belt. However, the induced perturbation does not impact the yearly averaged OHT. The frequency and intensity of the TCs appear to be substantially stationary through the entire 1950–2069 simulated period, as does the effect of the TCs on the OHT.

scholarly journals Changes in Tropical Cyclone Activity due to Global Warming: Results from a High-Resolution Coupled General Circulation Model

2008 ◽  
Vol 21 (20) ◽  
pp. 5204-5228 ◽  
Author(s):  
S. Gualdi ◽  
E. Scoccimarro ◽  
A. Navarra
Keyword(s):  
Global Warming ◽  
High Resolution ◽  
Tropical Cyclone ◽  
General Circulation Model ◽  
General Circulation ◽  
Large Scale ◽  
Vertical Wind Shear ◽  
Circulation Model ◽  
Co2 Concentration ◽  
Tropical Region

Abstract This study investigates the possible changes that greenhouse global warming might generate in the characteristics of tropical cyclones (TCs). The analysis has been performed using scenario climate simulations carried out with a fully coupled high-resolution global general circulation model. The capability of the model to reproduce a reasonably realistic TC climatology has been assessed by comparing the model results from a simulation of the twentieth century with observations. The model appears to be able to simulate tropical cyclone–like vortices with many features similar to the observed TCs. The simulated TC activity exhibits realistic geographical distribution, seasonal modulation, and interannual variability, suggesting that the model is able to reproduce the major basic mechanisms that link TC occurrence with large-scale circulation. The results from the climate scenarios reveal a substantial general reduction of TC frequency when the atmospheric CO2 concentration is doubled and quadrupled. The reduction appears particularly evident for the tropical western North Pacific (WNP) and North Atlantic (ATL). In the NWP the weaker TC activity seems to be associated with reduced convective instabilities. In the ATL region the weaker TC activity seems to be due to both the increased stability of the atmosphere and a stronger vertical wind shear. Despite the generally reduced TC activity, there is evidence of increased rainfall associated with the simulated cyclones. Finally, the action of the TCs remains well confined to the tropical region and the peak of TC number remains equatorward of 20° latitude in both hemispheres, notwithstanding the overall warming of the tropical upper ocean and the expansion poleward of warm SSTs.

scholarly journals An operational forecasting system for the meteorological and marine conditions in Mediterranean regional and coastal areas

2014 ◽  
Vol 11 (1) ◽  
pp. 11-23 ◽  
Author(s):  
M. Casaioli ◽  
F. Catini ◽  
R. Inghilesi ◽  
P. Lanucara ◽  
P. Malguzzi ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Regional Scale ◽  
Wave Climate ◽  
Limited Area ◽  
Ligurian Sea ◽  
Coastal System ◽  
Northern Adriatic ◽  
Wave Forecast ◽  
Forecasting System

Abstract. The coupling of a suite of meteorological limited area models with a wave prediction system based on the nesting of different wave models provides for medium-range sea state forecasts at the Mediterranean, regional and coastal scale. The new system has been operational at ISPRA since September 2012, after the upgrade of both the meteorological BOLAM model and large-scale marine components of the original SIMM forecasting system and the implementation of the new regional and coastal (WAM-SWAN coupling) chain of models. The coastal system is composed of nine regional-scale high-resolution grids, covering all Italian seas and six coastal grids at very high resolution, capable of accounting for the effects of the interaction between the incoming waves and the bathymetry. A preliminary analysis of the performance of the system is discussed here focusing on the ability of the system to simulate the mean features of the wave climate at the regional and sub-regional scale. The results refer to two different verification studies. The first is the comparison of the directional distribution of almost one year of wave forecasts against the known wave climate in northwestern Sardinia and central Adriatic Sea. The second is a sensitivity test on the effect on wave forecasts of the spatial resolution of the wind forcing, being the comparison between wave forecast and buoy data at two locations in the northern Adriatic and Ligurian Sea during several storm episodes in the period autumn 2012–winter 2013.

Modeling the Environmental Dynamics of the Northern Adriatic Sea with an explicit benthic-pelagic coupling.

2021 ◽  
Author(s):  
Marco Zavatarelli ◽  
Isabella Scroccaro ◽  
Tomas Lovato
Keyword(s):  
General Circulation ◽  
Adriatic Sea ◽  
Circulation Model ◽  
Open Boundary ◽  
Biogeochemical Model ◽  
Northern Adriatic Sea ◽  
Po River ◽  
Northern Adriatic ◽  
Benthic Pelagic Coupling ◽  
The Impact

<p>In the framework of the European Project H2020 "ODYSSEA" (Operating a network of integrated observatory systems in the Mediterranean SEA, http://odysseaplatform.eu/) a forecasting modeling system of the coupled physical and biogeochemical conditions of the Northern Adriatic Sea is under development.</p><p>The modeling system consists of the on-line coupling of the European general circulation model - NEMO (Nucleus for European Modeling of the Ocean, https://www.nemo-ocean.eu/), with the marine biogeochemical model - BFM (Biogeochemical Flux Model, bfm-community.eu/).<br>The biogeochemical component of the model includes the simulation of the biogeochemical processes of both water column and sediments and their coupling. The model is run for the first time in the Northern Adriatic Sea with an explicit benthic-pelagic coupling.</p><p>The horizontal spatial discretization is defined by a rectangular grid of 315 × 278 cells, having a horizontal resolution of about 800 m. The vertical resolution is defined at 2 m, with 48 z-levels regularly spaced. Currently the atmospheric forcing are the ECMWF 6hr analysis atmospheric fields. The river supplies of fresh water and nutrient salts consider the daily runoff of the Po river, while the other rivers within the study area are included as climatological values. The open boundary conditions of the modeling system come from the Copernicus Marine Environment Monitoring Service (CMEMS, http://marine.copernicus.eu/).</p><p>In this work, the hindcast simulations encompassing the period 2000 – 2009 are validated against available observations from in situ and satellite platforms for sea surface temperature, chlorophyll-a and dissolved inorganic nutrients and, in order to evaluate the impact of a resolved benthic biogeochemical dynamics,  compared against simulations results obtained utilising a simple benthic closure parameterisation.</p>

scholarly journals Coupled atmosphere ocean climate model simulations in the Mediterranean region: effect of a high-resolution marine model on cyclones and precipitation

2013 ◽  
Vol 13 (6) ◽  
pp. 1567-1577 ◽  
Author(s):  
A. Sanna ◽  
P. Lionello ◽  
S. Gualdi
Keyword(s):  
High Resolution ◽  
Mediterranean Sea ◽  
General Circulation ◽  
Climate Model ◽  
Interaction Strength ◽  
Circulation Model ◽  
Convective Precipitation ◽  
Northern Adriatic ◽  
Significant Difference ◽  
The Mediterranean

Abstract. In this study we investigate the importance of an eddy-permitting Mediterranean Sea circulation model on the simulation of atmospheric cyclones and precipitation in a climate model. This is done by analyzing results of two fully coupled GCM (general circulation models) simulations, differing only for the presence/absence of an interactive marine module, at very high-resolution (~ 1/16°), for the simulation of the 3-D circulation of the Mediterranean Sea. Cyclones are tracked by applying an objective Lagrangian algorithm to the MSLP (mean sea level pressure) field. On annual basis, we find a statistically significant difference in vast cyclogenesis regions (northern Adriatic, Sirte Gulf, Aegean Sea and southern Turkey) and in lifetime, giving evidence of the effect of both land–sea contrast and surface heat flux intensity and spatial distribution on cyclone characteristics. Moreover, annual mean convective precipitation changes significantly in the two model climatologies as a consequence of differences in both air–sea interaction strength and frequency of cyclogenesis in the two analyzed simulations.

scholarly journals Impact of model resolution on Holocene climate simulations of the Northern Hemisphere

2018 ◽  
Author(s):  
Axel Wagner ◽  
Gerrit Lohmann ◽  
Matthias Prange
Keyword(s):  
High Resolution ◽  
Radiative Forcing ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Boreal Winter ◽  
Temperature Anomalies ◽  
Air Temperatures ◽  
Geographical Regions ◽  
Simulated Surface

Abstract. This study demonstrates the dependence of simulated surface air temperatures on variations in grid resolution and resolution-dependent orography in simulations of the Mid-Holocene. A set of Mid-Holocene sensitivity experiments is carried out with the atmospheric general circulation model ECHAM5 forced with sea surface temperature and sea ice fields from coupled simulations. Each experiment was performed in two resolution modes: low (~ 3.75°, 19 vertical levels) and high (~ 1.1°, 31 vertical levels). Results are compared to respective preindustrial runs. It is found that the large-scale temperature anomalies for the Mid-Holocene (compared to the preindustrial) are significantly different in the low- and high-resolution versions. For boreal winter, differences are related to circulation changes caused by the response to thermal forcing in conjunction with orographic resolution. For summer, shortwave cloud radiative forcing emerges as the predominant factor. In summary, the simulated Mid-Holocene temperature differences (low versus high resolution) reveal a response that regionally exceeds the Mid-Holocene to preindustrial modelled temperature anomalies, and show partly reversed signs across the same geographical regions. Our results imply that climate change simulations sensitively depend on the chosen grid resolutions.

Modeling the biogeochemical dynamics of the Northern Adriatic Sea with an explicit benthic-pelagic coupling

2020 ◽  
Author(s):  
Isabella Scroccaro ◽  
Marco Zavatarelli ◽  
Tomas Lovato
Keyword(s):  
Mediterranean Sea ◽  
General Circulation ◽  
Adriatic Sea ◽  
Circulation Model ◽  
Horizontal Resolution ◽  
Open Boundary ◽  
Biogeochemical Model ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
The Mediterranean

<p>A high resolution three-dimensional (physical-biogeochemical) numerical model of the Northern Adriatic Sea has been implemented by coupling the European general circulation model - NEMO (Nucleus for European Modeling of the Ocean, https://www.nemo-ocean.eu/), with the marine biogeochemical model BFM (Biogeochemical Flux Model, bfm-community.eu/).</p><p>The modeling system is implemented with a horizontal resolution of about 800 m and a vertical resolution of 2 m, in z coordinates. The NEMO model is off-line nested at its open boundary with the Mediterranean Sea physical model of the Copernicus Marine Environment Monitoring Service (CMEMS, http://marine.copernicus.eu/).</p><p>The BFM component of the modeling system now includes a detailed and explicit representation of the benthic biogeochemical cycling (benthic fauna, organic matter, nutrients), as well as the dynamics of the benthic-pelagic processes.</p><p>The inclusion of the benthic dynamics in the 3D biogeochemical modeling of a shallow coastal basin, such as the Northern Adriatic Sea, represents an innovative application in the field of coastal and shelf biogeochemistry, since benthic biogeochemical processes can significantly constrain the coastal environmental dynamics.</p><p>Simulations have been performed in hindcasting mode with interannually varying physical (surface heat and water fluxes, including river runoff) and biogeochemical (river nutrient load) forcing. Results are validated against available observations from in situ and satellite platforms for sea surface temperatures, chlorophyll-a and dissolved inorganic nutrients, in order to explore the sensitivity of the pelagic environment to the inclusion of an explicit benthic dynamics and to evaluate issues related to model coupling and error/prediction limits.</p><p>The study is carried out in the framework of the European Project H2020 "ODYSSEA" (Operating a network of integrated observatory systems in the Mediterranean SEA, http://odysseaplatform.eu/), with the final goal to build an on-line forecasting modeling system of the Northern Adriatic Sea.</p>

scholarly journals A high resolution hydrodynamic 3-D model simulation of the malta shelf area

2003 ◽  
Vol 21 (1) ◽  
pp. 323-344 ◽  
Author(s):  
A. F. Drago ◽  
R. Sorgente ◽  
A. Ribotti
Keyword(s):  
High Resolution ◽  
Seasonal Variability ◽  
General Circulation ◽  
Large Scale ◽  
Current Knowledge ◽  
Model Simulation ◽  
Circulation Model ◽  
Surface Flow ◽  
Open Boundary ◽  
Shelf Area

Abstract. The seasonal variability of the water masses and transport in the Malta Channel and proximity of the Maltese Islands have been simulated by a high resolution (1.6 km horizontal grid on average, 15 vertical sigma layers) eddy resolving primitive equation shelf model (ROSARIO-I). The numerical simulation was run with climatological forcing and includes thermohaline dynamics with a turbulence scheme for the vertical mixing coefficients on the basis of the Princeton Ocean Model (POM). The model has been coupled by one-way nesting along three lateral boundaries (east, south and west) to an intermediate coarser resolution model (5 km) implemented over the Sicilian Channel area. The fields at the open boundaries and the atmospheric forcing at the air-sea interface were applied on a repeating "perpetual" year climatological cycle. The ability of the model to reproduce a realistic circulation of the Sicilian-Maltese shelf area has been demonstrated. The skill of the nesting procedure was tested by model-modelc omparisons showing that the major features of the coarse model flow field can be reproduced by the fine model with additional eddy space scale components. The numerical results included upwelling, mainly in summer and early autumn, along the southern coasts of Sicily and Malta; a strong eastward shelf surface flow along shore to Sicily, forming part of the Atlantic Ionian Stream, with a presence throughout the year and with significant seasonal modulation, and a westward winter intensified flow of LIW centered at a depth of around 280 m under the shelf break to the south of Malta. The seasonal variability in the thermohaline structure of the domain and the associated large-scale flow structures can be related to the current knowledge on the observed hydrography of the area. The level of mesoscale resolution achieved by the model allowed the spatial and temporal evolution of the changing flow patterns, triggered by internal dynamics, to be followed in detail. This modelling effort has initiated the treatment of the open boundary conditions problem in view of the future implementation of shelf-scale real-time ocean forecasting through the sequential nesting of a hierarchy of successively embedded model domains for the downscaling of the hydrodynamics from the coarse grid Ocean General Circulation Model of the whole Mediterranean Sea to finer grids in coastal areas. Key words. Oceanography: general (continental shelf processes; numerical modelling) Oceanography: physical (general circulation)

scholarly journals Response of Tropical Cyclones to Idealized Climate Change Experiments in a Global High-Resolution Coupled General Circulation Model

2013 ◽  
Vol 26 (20) ◽  
pp. 7966-7980 ◽  
Author(s):  
Ray Bell ◽  
Jane Strachan ◽  
Pier Luigi Vidale ◽  
Kevin Hodges ◽  
Malcolm Roberts
Keyword(s):  
High Resolution ◽  
Tropical Cyclone ◽  
Tropical Cyclones ◽  
General Circulation ◽  
Large Scale ◽  
Vertical Wind Shear ◽  
Circulation Model ◽  
Walker Circulation ◽  
Tropical Cyclone Activity ◽  
Cyclone Activity

Abstract The authors present an assessment of how tropical cyclone activity might change owing to the influence of increased atmospheric carbon dioxide concentrations, using the U.K. High-Resolution Global Environment Model (HiGEM) with N144 resolution (~90 km in the atmosphere and ~40 km in the ocean). Tropical cyclones are identified using a feature-tracking algorithm applied to model output. Tropical cyclones from idealized 30-yr 2×CO2 (2CO2) and 4×CO2 (4CO2) simulations are compared to those identified in a 150-yr present-day simulation that is separated into a five-member ensemble of 30-yr integrations. Tropical cyclones are shown to decrease in frequency globally by 9% in the 2CO2 and 26% in the 4CO2. Tropical cyclones only become more intense in the 4CO2; however, uncoupled time slice experiments reveal an increase in intensity in the 2CO2. An investigation into the large-scale environmental conditions, known to influence tropical cyclone activity in the main development regions, is used to determine the response of tropical cyclone activity to increased atmospheric CO2. A weaker Walker circulation and a reduction in zonally averaged regions of updrafts lead to a shift in the location of tropical cyclones in the Northern Hemisphere. A decrease in mean ascent at 500 hPa contributes to the reduction of tropical cyclones in the 2CO2 in most basins. The larger reduction of tropical cyclones in the 4CO2 arises from further reduction of the mean ascent at 500 hPa and a large enhancement of vertical wind shear, especially in the Southern Hemisphere, North Atlantic, and northeast Pacific.

scholarly journals Towards a regional ocean forecasting system for the IBI (Iberia-Biscay-Ireland area): developments and improvements within the ECOOP project framework

Ocean Science ◽  
2012 ◽  
Vol 8 (2) ◽  
pp. 143-159 ◽  
Author(s):  
S. Cailleau ◽  
J. Chanut ◽  
J.-M. Lellouche ◽  
B. Levier ◽  
C. Maraldi ◽  
...  
Keyword(s):  
General Circulation ◽  
Large Scale ◽  
Vertical Mixing ◽  
Circulation Model ◽  
Storm Surges ◽  
Ocean General Circulation Model ◽  
Tidal Mixing ◽  
Basin Scale ◽  
Forecasting System ◽  
Ocean Forecasting

Abstract. The regional ocean operational system remains a key element in downscaling from large scale (global or basin scale) systems to coastal ones. It enables the transition between systems in which the resolution and the resolved physics are quite different. Indeed, coastal applications need a system to predict local high frequency events (inferior to the day) such as storm surges, while deep sea applications need a system to predict large scale lower frequency ocean features. In the framework of the ECOOP project, a regional system for the Iberia-Biscay-Ireland area has been upgraded from an existing V0 version to a V2. This paper focuses on the improvements from the V1 system, for which the physics are close to a large scale basin system, to the V2 for which the physics are more adapted to shelf and coastal issues. Strong developments such as higher regional physics resolution in the NEMO Ocean General Circulation Model for tides, non linear free surface and adapted vertical mixing schemes among others have been implemented in the V2 version. Thus, regional thermal fronts due to tidal mixing now appear in the latest version solution and are quite well positioned. Moreover, simulation of the stratification in shelf areas is also improved in the V2.

Sign in / Sign up

Export Citation Format

Share Document