Numerical simulation and decomposition of kinetic energies in the Central Mediterranean Sea: insight on mesoscale circulation and energy conversion

Abstract. The spatial and temporal variability of eddy and mean kinetic energy of the Central Mediterranean Sea has been investigated, from January 2008 to December 2010, by mean of a numerical simulation mainly to quantify the mesoscale dynamics and their relationships with physical forcing. In order to understand the energy redistribution processes, the baroclinic energy conversion has been analysed, suggesting hypotheses about the drivers of the mesoscale activity in this area. The ocean model used is based on the Princeton Ocean Model implemented at 1/32° horizontal resolution. Surface momentum and buoyancy fluxes are interactively computed by mean of standard bulk formulae using predicted model Sea Surface Temperature and atmospheric variables provided by the European Centre for Medium Range Weather Forecast operational analyses. At its lateral boundaries the model is one-way nested within the Mediterranean Forecasting System operational products. The model domain has been subdivided in four sub-regions: Sardinia channel and southern Tyrrhenian Sea, Sicily channel, eastern Tunisian shelf and Libyan Sea. Temporal evolution of eddy and mean kinetic energy has been analysed, on each of the four sub-regions composing the model domain, showing different behaviours. On annual scales and within the first 5 m depth, the eddy kinetic energy represents approximately the 60 % of the total kinetic energy over the whole domain, confirming the strong mesoscale nature of the surface current flows in this area. The analyses show that the model well reproduces the path and the temporal behaviour of the main known sub-basin circulation features. New mesoscale structures have been also identified, from numerical results and direct observations, for the first time as the Pantelleria Vortex and the Medina Gyre. The classical the kinetic energy decomposition (eddy and mean) allowed to depict and to quantify the stable and fluctuating parts of the circulation in the region, and to differentiate the four sub-regions as function of relative and absolute strength of the mesoscale activity. Furthermore the Baroclinic Energy Conversion term shows that in the Sardinia Channel the mesoscale activity, due to baroclinic instabilities, is significantly larger than in the other sub-regions, while a negative sign of the energy conversion, meaning a transfer of energy from the Eddy Kinetic Energy to the Eddy Available Potential Energy, has been recorded only for the surface layers of the Sicily Channel during summer.

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Numerical simulation and decomposition of kinetic energy in the Central Mediterranean: insight on mesoscale circulation and energy conversion

Ocean Science ◽

10.5194/os-7-503-2011 ◽

2011 ◽

Vol 7 (4) ◽

pp. 503-519 ◽

Cited By ~ 51

Author(s):

R. Sorgente ◽

A. Olita ◽

P. Oddo ◽

L. Fazioli ◽

A. Ribotti

Keyword(s):

Numerical Simulation ◽

Kinetic Energy ◽

Energy Conversion ◽

Ocean Model ◽

Eddy Kinetic Energy ◽

Tyrrhenian Sea ◽

Central Mediterranean ◽

Baroclinic Energy Conversion ◽

Sicily Channel ◽

Mean Kinetic Energy

Abstract. The spatial and temporal variability of eddy and mean kinetic energy of the Central Mediterranean region has been investigated, from January 2008 to December 2010, by mean of a numerical simulation mainly to quantify the mesoscale dynamics and their relationships with physical forcing. In order to understand the energy redistribution processes, the baroclinic energy conversion has been analysed, suggesting hypotheses about the drivers of the mesoscale activity in this area. The ocean model used is based on the Princeton Ocean Model implemented at 1/32° horizontal resolution. Surface momentum and buoyancy fluxes are interactively computed by mean of standard bulk formulae using predicted model Sea Surface Temperature and atmospheric variables provided by the European Centre for Medium Range Weather Forecast operational analyses. At its lateral boundaries the model is one-way nested within the Mediterranean Forecasting System operational products. The model domain has been subdivided in four sub-regions: Sardinia channel and southern Tyrrhenian Sea, Sicily channel, eastern Tunisian shelf and Libyan Sea. Temporal evolution of eddy and mean kinetic energy has been analysed, on each of the four sub-regions, showing different behaviours. On annual scales and within the first 5 m depth, the eddy kinetic energy represents approximately the 60 % of the total kinetic energy over the whole domain, confirming the strong mesoscale nature of the surface current flows in this area. The analyses show that the model well reproduces the path and the temporal behaviour of the main known sub-basin circulation features. New mesoscale structures have been also identified, from numerical results and direct observations, for the first time as the Pantelleria Vortex and the Medina Gyre. The classical kinetic energy decomposition (eddy and mean) allowed to depict and to quantify the permanent and fluctuating parts of the circulation in the region, and to differentiate the four sub-regions as function of relative and absolute strength of the mesoscale activity. Furthermore the Baroclinic Energy Conversion term shows that in the Sardinia Channel the mesoscale activity, due to baroclinic instabilities, is significantly larger than in the other sub-regions, while a negative sign of the energy conversion, meaning a transfer of energy from the Eddy Kinetic Energy to the Eddy Available Potential Energy, has been recorded only for the surface layers of the Sicily Channel during summer.

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Transient eddy kinetic energetics on Mars in three reanalysis datasets

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-21-0038.1 ◽

2021 ◽

Author(s):

J. Michael Battalio

Keyword(s):

Kinetic Energy ◽

Energy Conversion ◽

Northern Hemisphere ◽

Thermal Emission ◽

Ensemble Member ◽

Eddy Kinetic Energy ◽

Mean Flow ◽

Short Period ◽

Barotropic Energy Conversion ◽

Baroclinic Energy Conversion

AbstractThe ability of Martian reanalysis datasets to represent the growth and decay of short-period (1.5 < P < 8 sol) transient eddies is compared across the Mars Analysis Correction Data Assimilation (MACDA), Open access to Mars Assimilated Remote Soundings (OpenMARS), and Ensemble Mars Reanalysis System (EMARS). Short-period eddies are predominantly surface-based, have the largest amplitudes in the northern hemisphere, and are found, in order of decreasing eddy kinetic energy amplitude, in Utopia, Acidalia, and Arcadia Planitae in the northern hemisphere, and south of the Tharsis Plateau and between Argyre and Hellas Basins in the southern hemisphere. Short-period eddies grow on the upstream (western) sides of basins via baroclinic energy conversion and by extracting energy from the mean flow and long-period (P > 8 sol) eddies when interacting with high relief. Overall, the combined impact of barotropic energy conversion is a net loss of eddy kinetic energy, which rectifies previous conflicting results. When Thermal Emission Spectrometer observations are assimilated (Mars years 24–27), all three reanalyses agree on eddy amplitude and timing, but during the Mars Climate Sounder (MCS) observational era (Mars years 28–33), eddies are less constrained. The EMARS ensemble member has considerably higher eddy generation than the ensemble mean, and bulk eddy amplitudes in the deterministic OpenMARS reanalysis agree with the EMARS ensemble rather than the EMARS member. Thus, analysis of individual eddies during the MCS era should only be performed when eddy amplitudes are large and when there is agreement across reanalyses.

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Predictive distribution models of European hake in the south-central Mediterranean Sea

Hydrobiologia ◽

10.1007/s10750-017-3338-5 ◽

2017 ◽

Vol 821 (1) ◽

pp. 153-172 ◽

Cited By ~ 3

Author(s):

G. Garofalo ◽

S. Fezzani ◽

F. Gargano ◽

G. Milisenda ◽

O. Ben Abdallah ◽

...

Keyword(s):

Mediterranean Sea ◽

Predictive Distribution ◽

The South ◽

Distribution Models ◽

Central Mediterranean ◽

South Central ◽

Central Mediterranean Sea ◽

European Hake

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Ecological status assessment and non-indigenous species in industrial and fishing harbours of the Gulf of Gabès (central Mediterranean Sea)

Environmental Science and Pollution Research ◽

10.1007/s11356-021-14729-1 ◽

2021 ◽

Author(s):

Nawfel Mosbahi ◽

Jean-Philippe Pezy ◽

Lassad Neifar ◽

Jean-Claude Dauvin

Keyword(s):

Mediterranean Sea ◽

Ecological Status ◽

Indigenous Species ◽

Central Mediterranean ◽

Gulf Of Gabes ◽

Gulf Of Gabès ◽

Central Mediterranean Sea ◽

Ecological Status Assessment ◽

Status Assessment ◽

Non Indigenous Species

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Correction to: Assessment of cetacean–fishery interactions in the marine food web of the Gulf of Taranto (Northern Ionian Sea, Central Mediterranean Sea)

Reviews in Fish Biology and Fisheries ◽

10.1007/s11160-020-09630-y ◽

2021 ◽

Author(s):

Roberto Carlucci ◽

Francesca Capezzuto ◽

Giulia Cipriano ◽

Gianfranco D’Onghia ◽

Carmelo Fanizza ◽

...

Keyword(s):

Food Web ◽

Mediterranean Sea ◽

Ionian Sea ◽

Central Mediterranean ◽

Marine Food Web ◽

Central Mediterranean Sea ◽

Marine Food ◽

Fishery Interactions

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Air–Sea Interaction in the Central Mediterranean Sea: Assessment of Reanalysis and Satellite Observations

Remote Sensing ◽

10.3390/rs13112188 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2188

Author(s):

Salvatore Marullo ◽

Jaime Pitarch ◽

Marco Bellacicco ◽

Alcide Giorgio di Sarra ◽

Daniela Meloni ◽

...

Keyword(s):

Heat Flux ◽

Mediterranean Sea ◽

Seasonal Cycle ◽

Heat Fluxes ◽

Meteorological Variables ◽

Central Mediterranean ◽

High Quality ◽

Central Mediterranean Sea ◽

In Situ Observations

Air–sea heat fluxes are essential climate variables, required for understanding air–sea interactions, local, regional and global climate, the hydrological cycle and atmospheric and oceanic circulation. In situ measurements of fluxes over the ocean are sparse and model reanalysis and satellite data can provide estimates at different scales. The accuracy of such estimates is therefore essential to obtain a reliable description of the occurring phenomena and changes. In this work, air–sea radiative fluxes derived from the SEVIRI sensor onboard the MSG satellite and from ERA5 reanalysis have been compared to direct high quality measurements performed over a complete annual cycle at the ENEA oceanographic observatory, near the island of Lampedusa in the Central Mediterranean Sea. Our analysis reveals that satellite derived products overestimate in situ direct observations of the downwelling short-wave (bias of 6.1 W/m2) and longwave (bias of 6.6 W/m2) irradiances. ERA5 reanalysis data show a negligible positive bias (+1.0 W/m2) for the shortwave irradiance and a large negative bias (−17 W/m2) for the longwave irradiance with respect to in situ observations. ERA5 meteorological variables, which are needed to calculate the air–sea heat flux using bulk formulae, have been compared with in situ measurements made at the oceanographic observatory. The two meteorological datasets show a very good agreement, with some underestimate of the wind speed by ERA5 for high wind conditions. We investigated the impact of different determinations of heat fluxes on the near surface sea temperature (1 m depth), as determined by calculations with a one-dimensional numerical model, the General Ocean Turbulence Model (GOTM). The sensitivity of the model to the different forcing was measured in terms of differences with respect to in situ temperature measurements made during the period under investigation. All simulations reproduced the true seasonal cycle and all high frequency variabilities. The best results on the overall seasonal cycle were obtained when using meteorological variables in the bulk formulae formulations used by the model itself. The derived overall annual net heat flux values were between +1.6 and 40.4 W/m2, depending on the used dataset. The large variability obtained with different datasets suggests that current determinations of the heat flux components and, in particular, of the longwave irradiance, need to be improved. The ENEA oceanographic observatory provides a complete, long-term, high resolution time series of high quality in situ observations. In the future, more similar sites worldwide will be needed for model and satellite validations and to improve the determination of the air–sea exchange and the understanding of related processes.

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