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Knowledge about marine circulation and its variability is a basic requirement for the correct management of activities aimed at exploiting marine resources and for the prevention and eventual mitigation of the risks involved. The activities of the Marine Hazard Project, to which this special number of Sustainability is dedicated, focus on geothermal resources connected with some submerged volcanic systems located in the Tyrrhenian Sea. This sea hosts delicate coastal and marine ecosystems, and is characterized by rich dynamics, both driven by the interaction of the local forcing with the complex morphology and bathymetry of the basin, and by exchanges with adjacent sub-basins which take place at all depths. The main purpose of the present review is to summarize the present understanding of the Tyrrhenian Sea circulation and its variability, with special emphasis on the results of experimental and modelling works of the last decade.
Roberto Iacono; Ernesto Napolitano; Massimiliano Palma; Gianmaria Sannino. The Tyrrhenian Sea Circulation: A Review of Recent Work. Sustainability 2021, 13, 6371 .
AMA StyleRoberto Iacono, Ernesto Napolitano, Massimiliano Palma, Gianmaria Sannino. The Tyrrhenian Sea Circulation: A Review of Recent Work. Sustainability. 2021; 13 (11):6371.
Chicago/Turabian StyleRoberto Iacono; Ernesto Napolitano; Massimiliano Palma; Gianmaria Sannino. 2021. "The Tyrrhenian Sea Circulation: A Review of Recent Work." Sustainability 13, no. 11: 6371.
Lateral advection affects the spatial distribution of dissolved substances in the ocean but very few studies, so far, have been devoted to describe and quantify its impact on the distribution of dissolved organic carbon (DOC) which, in oligotrophic environments, accounts for the largest fraction of chemical energy. In this contribution, using an integrated approach, we explore the importance of surface advection on carbon dynamics in the Western Mediterranean Sea, where strong inter-basin differences in primary production do exist. Detailed information on the surface circulation, derived from high-resolution model simulations, is combined with the analysis of spatially resolved, accurate DOC vertical profiles, repeated over time. Our data show that surface circulation plays a crucial role in regulating DOC concentrations and distributions in the Tyrrhenian Sea and that horizontal transport of DOC into the Tyrrhenian Sea is of the same order of magnitude as in-situ DOC production. Our study addresses this process for the first time in the Mediterranean Sea, whose small size allows for fast, inter-basin transfer times which, in turn, favors the preservation of the DOC stock produced elsewhere. We highlight that this mechanism may be important also in other regions of the oceans, where surface advection may set up a sort of compensation among regions with different trophic regimes, thus smoothing trophic gradients. We posit that understanding these transport processes is a crucial and preliminary step to understand and quantify all the other processes (biological, chemical, geological) that influence DOC distribution on a variety of timescales.
Chiara Santinelli; Roberto Iacono; Ernesto Napolitano; Maurizio Ribera D’Alcalá. Surface transport of DOC acts as a trophic link among Mediterranean sub-basins. Deep Sea Research Part I: Oceanographic Research Papers 2021, 170, 103493 .
AMA StyleChiara Santinelli, Roberto Iacono, Ernesto Napolitano, Maurizio Ribera D’Alcalá. Surface transport of DOC acts as a trophic link among Mediterranean sub-basins. Deep Sea Research Part I: Oceanographic Research Papers. 2021; 170 ():103493.
Chicago/Turabian StyleChiara Santinelli; Roberto Iacono; Ernesto Napolitano; Maurizio Ribera D’Alcalá. 2021. "Surface transport of DOC acts as a trophic link among Mediterranean sub-basins." Deep Sea Research Part I: Oceanographic Research Papers 170, no. : 103493.
Water exchanges between the Tyrrhenian Sea and the Liguro-Provençal basin occur through the Corsica Channel, a narrow passage between Corsica and the Elba Island, near the Italian coast. It has long been known that the Channel hosts a robust Tyrrhenian outflow in winter, which penetrates far into the Ligurian Sea, reaching the site where deep-water formation takes place. The summer circulation in the area, and, more generally, in the eastern part of the Ligurian Sea, is less well known. Several experimental and modelling works in the last decade have pointed out the presence of an anticyclone in the Channel area, sometimes referred to as Ligurian anticyclone, which could modulate the exchanges between the two basins in summer, and could strongly affect the dispersion properties in the south-eastern Ligurian Sea, with implications on the local, delicate marine environment. In this work, we focus on this structure, and on the role it plays in the local circulation, seeking information from long datasets of satellite observations (sea level, sea surface temperature and turbidity) that are now available. We find that the Ligurian anticyclone is a recurrent feature of the local circulation in summer. Its core is located between Cap Corse (the peninsula at the northern end of Corsica) and the Elba Island, but the anticyclone may extend till the Italian coast, and it may sometimes be more elongated in the latitudinal direction, and/or more displaced towards north. In some years, a companion anticyclonic vortex is found more to the north, in the north-eastern portion of the Ligurian Sea, but the robustness of this structure is unclear. Analysis of the ERA5 winds indicates that the Ligurian anticyclone is likely driven by an area of negative wind stress curl usually present near Cap Corse in summer, even though contributions from the surrounding circulation cannot be a priori excluded.
Roberto Iacono; Ernesto Napolitano. Aspects of the summer circulation in the eastern Ligurian Sea. Deep Sea Research Part I: Oceanographic Research Papers 2020, 166, 103407 .
AMA StyleRoberto Iacono, Ernesto Napolitano. Aspects of the summer circulation in the eastern Ligurian Sea. Deep Sea Research Part I: Oceanographic Research Papers. 2020; 166 ():103407.
Chicago/Turabian StyleRoberto Iacono; Ernesto Napolitano. 2020. "Aspects of the summer circulation in the eastern Ligurian Sea." Deep Sea Research Part I: Oceanographic Research Papers 166, no. : 103407.
Roberto Iacono. Comment on “Classification of Lie point symmetries for quadratic Liénard type equation ẍ + f(x) ẋ2 + g(x) = 0” [J. Math. Phys. 54, 053506 (2013)]. Journal of Mathematical Physics 2020, 61, 044101 .
AMA StyleRoberto Iacono. Comment on “Classification of Lie point symmetries for quadratic Liénard type equation ẍ + f(x) ẋ2 + g(x) = 0” [J. Math. Phys. 54, 053506 (2013)]. Journal of Mathematical Physics. 2020; 61 (4):044101.
Chicago/Turabian StyleRoberto Iacono. 2020. "Comment on “Classification of Lie point symmetries for quadratic Liénard type equation ẍ + f(x) ẋ2 + g(x) = 0” [J. Math. Phys. 54, 053506 (2013)]." Journal of Mathematical Physics 61, no. 4: 044101.
The Lambert W-function is the solution to the transcendental equation W(x)eW(x) = x. It has two real branches, one of which, for x ∈ [−1/e, ∞], is usually denoted as the principal branch. On this branch, the function grows from − 1 to infinity, logarithmically at large x. The present work is devoted to the construction of accurate approximations for the principal branch of the W-function. In particular, a simple, global analytic approximation is derived that covers the whole branch with a maximum relative error smaller than 5 × 10−3. Starting from it, machine precision accuracy is reached everywhere with only three steps of a quadratically convergent iterative scheme, here examined for the first time, which is more efficient than standard Newton’s iteration at large x. Analytic bounds for W are also constructed, for x > e, which are much tighter than those currently available. It is noted that the exponential of the upper bounding function yields an upper bound for the prime counting function π(n) that is better than the well-known Chebyshev’s estimates at large n. Finally, the construction of accurate approximations to W based on Chebyshev spectral theory is discussed; the difficulties involved are highlighted, and methods to overcome them are presented.
Roberto Iacono; John P. Boyd. New approximations to the principal real-valued branch of the Lambert W-function. Advances in Computational Mathematics 2017, 43, 1403 -1436.
AMA StyleRoberto Iacono, John P. Boyd. New approximations to the principal real-valued branch of the Lambert W-function. Advances in Computational Mathematics. 2017; 43 (6):1403-1436.
Chicago/Turabian StyleRoberto Iacono; John P. Boyd. 2017. "New approximations to the principal real-valued branch of the Lambert W-function." Advances in Computational Mathematics 43, no. 6: 1403-1436.
E. Napolitano; R. Iacono; R. Sorgente; L. Fazioli; A. Olita; A. Cucco; P. Oddo; A. Guarnieri. The regional forecasting systems of the Italian seas. Journal of Operational Oceanography 2016, 9, s66 -s76.
AMA StyleE. Napolitano, R. Iacono, R. Sorgente, L. Fazioli, A. Olita, A. Cucco, P. Oddo, A. Guarnieri. The regional forecasting systems of the Italian seas. Journal of Operational Oceanography. 2016; 9 (sup1):s66-s76.
Chicago/Turabian StyleE. Napolitano; R. Iacono; R. Sorgente; L. Fazioli; A. Olita; A. Cucco; P. Oddo; A. Guarnieri. 2016. "The regional forecasting systems of the Italian seas." Journal of Operational Oceanography 9, no. sup1: s66-s76.
R. Iacono; Matteo De Felice. Constructing analytic approximate solutions to the Lane–Emden equation. Physics Letters A 2015, 379, 1802 -1807.
AMA StyleR. Iacono, Matteo De Felice. Constructing analytic approximate solutions to the Lane–Emden equation. Physics Letters A. 2015; 379 (32-33):1802-1807.
Chicago/Turabian StyleR. Iacono; Matteo De Felice. 2015. "Constructing analytic approximate solutions to the Lane–Emden equation." Physics Letters A 379, no. 32-33: 1802-1807.
R. Iacono; John P. Boyd. Simple analytic approximations for the Blasius problem. Physica D: Nonlinear Phenomena 2015, 310, 72 -78.
AMA StyleR. Iacono, John P. Boyd. Simple analytic approximations for the Blasius problem. Physica D: Nonlinear Phenomena. 2015; 310 ():72-78.
Chicago/Turabian StyleR. Iacono; John P. Boyd. 2015. "Simple analytic approximations for the Blasius problem." Physica D: Nonlinear Phenomena 310, no. : 72-78.
We examine the integrability properties of the Einstein field equations for static, spherically symmetric fluid spheres, complemented with an isothermal equation of state, ρ = np. In this case, Einstein's equations can be reduced to a nonlinear, autonomous second order ordinary differential equation (ODE) for m/R (m is the mass inside the radius R) that has been solved analytically only for n = −1 and n = −3, yielding the cosmological solutions by De Sitter and Einstein, respectively, and for n = −5, case for which the solution can be derived from the De Sitter's one using a symmetry of Einstein's equations. The solutions for these three cases are of Liouvillian type, since they can be expressed in terms of elementary functions. Here, we address the question of whether Liouvillian solutions can be obtained for other values of n. To do so, we transform the second order equation into an equivalent autonomous Lotka–Volterra quadratic polynomial differential system in R2, and characterize the Liouvillian integrability of this system using Darboux theory. We find that the Lotka–Volterra system possesses Liouvillian first integrals for n = −1, −3, −5, which descend from the existence of invariant algebraic curves of degree one, and for n = −6, a new solvable case, associated to an invariant algebraic curve of higher degree (second). For any other value of n, eventual first integrals of the Lotka–Volterra system, and consequently of the second order ODE for the mass function must be non-Liouvillian. This makes the existence of other solutions of the isothermal fluid sphere problem with a Liouvillian metric quite unlikely.
Roberto Iacono; Jaume Llibre. Liouvillian integrability of gravitating static isothermal fluid spheres. Journal of Mathematical Physics 2014, 55, 102501 .
AMA StyleRoberto Iacono, Jaume Llibre. Liouvillian integrability of gravitating static isothermal fluid spheres. Journal of Mathematical Physics. 2014; 55 (10):102501.
Chicago/Turabian StyleRoberto Iacono; Jaume Llibre. 2014. "Liouvillian integrability of gravitating static isothermal fluid spheres." Journal of Mathematical Physics 55, no. 10: 102501.
We derive accurate analytic approximations to the solution of the isothermal Lane–Emden equation, a basic equation in Astrophysics that describes the Newtonian equilibrium structure of self-gravitating, isothermal fluid spheres. The solutions we obtain, using analytic arguments and rational approximations, have simple forms, and are accurate over a radial extent that is much larger than that covered by conventional series expansions around the origin. Our best approximation has a maximum error on density of 0.04 % at 10 core radii, and is still within 1 % from an accurate numerical solution at a radius three times larger.
R. Iacono; Matteo De Felice. Approximate analytic solutions to the isothermal Lane–Emden equation. Celestial Mechanics and Dynamical Astronomy 2014, 118, 291 -298.
AMA StyleR. Iacono, Matteo De Felice. Approximate analytic solutions to the isothermal Lane–Emden equation. Celestial Mechanics and Dynamical Astronomy. 2014; 118 (3):291-298.
Chicago/Turabian StyleR. Iacono; Matteo De Felice. 2014. "Approximate analytic solutions to the isothermal Lane–Emden equation." Celestial Mechanics and Dynamical Astronomy 118, no. 3: 291-298.
New insights into the structure and variability of the Tyrrhenian Sea's surface circulation are obtained through the analysis of a very long series of altimetric observations (1993–2010). In late winter and part of spring, a consistent mean flow is individuated in the eastern Tyrrhenian Sea, formed by a stream of Atlantic water that meanders around four anticyclonic structures located along the Italian coast, which have smaller cyclonic companions offshore. The signatures of these vortices are also found in images of chlorophyll and sea surface temperature, as well as in modeling results, both from a high-resolution operational model of the Tyrrhenian Sea's circulation and from a dedicated numerical simulation. Analysis of the energy exchange between eddies and mean flow, together with numerical evidence, suggests that this winter–spring circulation pattern may result from basin-scale instability of the Atlantic stream. In summer, the dynamic is dominated by a well-known dipole located to the east of the Bonifacio Strait. However, in the eastern part of the basin, an anticyclonic cell is also found, probably driven by the negative wind stress curl present in summer in this region. The cell encompasses two anticyclonic vortices located in the areas of the Vavilov and Marsili Seamounts. A multichannel singular spectral analysis of the altimetric time series reveals that, besides the expected, dominant seasonal mode, a significant low-frequency mode of variability is also present. This mode has a period of about six years and is mostly localized in the western part of the basin.
R. Iacono; E. Napolitano; Salvatore Marullo; Vincenzo Artale; A. Vetrano. Seasonal Variability of the Tyrrhenian Sea Surface Geostrophic Circulation as Assessed by Altimeter Data. Journal of Physical Oceanography 2013, 43, 1710 -1732.
AMA StyleR. Iacono, E. Napolitano, Salvatore Marullo, Vincenzo Artale, A. Vetrano. Seasonal Variability of the Tyrrhenian Sea Surface Geostrophic Circulation as Assessed by Altimeter Data. Journal of Physical Oceanography. 2013; 43 (8):1710-1732.
Chicago/Turabian StyleR. Iacono; E. Napolitano; Salvatore Marullo; Vincenzo Artale; A. Vetrano. 2013. "Seasonal Variability of the Tyrrhenian Sea Surface Geostrophic Circulation as Assessed by Altimeter Data." Journal of Physical Oceanography 43, no. 8: 1710-1732.
In this paper we present the Pilot Project PRIMI, designed to provide information on marine oil spills, and its validation campaign, held in august 2009, conducted with the oceanography ship Urania. During the experiment CosmoSkymed has provided an extraordinary contribution supplying almost any day images over the area inspected by the ship and in some cases also images requested with short notice.
F. Nirchio; G. Pandiscia; G. Ruggieri; Rosalia Santoleri; Nadia Pinardi; P. Trivero; C. Castellani; F. Tataranni; A. Masini; Maria Adamo; Renata Archetti; W. Biamino; Francesco Bignami; Emanuele Bohm; M. Borasi; B. Buongiorno Nardelli; M. Cavagnero; F. Colao; Simone Colella; G. Coppini; V. Debettio; G. De Carolis; M. De Dominicis; V. Forneris; F. Fontebasso; A. Griffa; R. Iacono; E. Lombardi; Salvatore Marullo; G. Manzella; A. Mercatini; E. Napolitano; A. Pisano; F. Reseghetti; R. Sorgente; M. Sprovieri; G. Terranova; Gianluca Volpe; Enrico Zambianchi. Contribution of Cosmo/SkyMed data into PRIMI: A pilot project on marine oil pollution. results after one year of operations. 2010 IEEE International Geoscience and Remote Sensing Symposium 2010, 4799 -4802.
AMA StyleF. Nirchio, G. Pandiscia, G. Ruggieri, Rosalia Santoleri, Nadia Pinardi, P. Trivero, C. Castellani, F. Tataranni, A. Masini, Maria Adamo, Renata Archetti, W. Biamino, Francesco Bignami, Emanuele Bohm, M. Borasi, B. Buongiorno Nardelli, M. Cavagnero, F. Colao, Simone Colella, G. Coppini, V. Debettio, G. De Carolis, M. De Dominicis, V. Forneris, F. Fontebasso, A. Griffa, R. Iacono, E. Lombardi, Salvatore Marullo, G. Manzella, A. Mercatini, E. Napolitano, A. Pisano, F. Reseghetti, R. Sorgente, M. Sprovieri, G. Terranova, Gianluca Volpe, Enrico Zambianchi. Contribution of Cosmo/SkyMed data into PRIMI: A pilot project on marine oil pollution. results after one year of operations. 2010 IEEE International Geoscience and Remote Sensing Symposium. 2010; ():4799-4802.
Chicago/Turabian StyleF. Nirchio; G. Pandiscia; G. Ruggieri; Rosalia Santoleri; Nadia Pinardi; P. Trivero; C. Castellani; F. Tataranni; A. Masini; Maria Adamo; Renata Archetti; W. Biamino; Francesco Bignami; Emanuele Bohm; M. Borasi; B. Buongiorno Nardelli; M. Cavagnero; F. Colao; Simone Colella; G. Coppini; V. Debettio; G. De Carolis; M. De Dominicis; V. Forneris; F. Fontebasso; A. Griffa; R. Iacono; E. Lombardi; Salvatore Marullo; G. Manzella; A. Mercatini; E. Napolitano; A. Pisano; F. Reseghetti; R. Sorgente; M. Sprovieri; G. Terranova; Gianluca Volpe; Enrico Zambianchi. 2010. "Contribution of Cosmo/SkyMed data into PRIMI: A pilot project on marine oil pollution. results after one year of operations." 2010 IEEE International Geoscience and Remote Sensing Symposium , no. : 4799-4802.
It is shown that a sufficient condition for stability by P. Ripa, based on the monotonicity of the flow potential vorticity (PV), can be used to prove linear stability of isolated shallow water vortices over localized topographic features. Stable axisymmetric vortices over axisymmetric topography that satisfy Ripa’s condition are explicitly constructed by using a simple two-step, fully analytic approach. First, for a given velocity profile, the topography is found that yields a steady-state, constant-PV solution of the shallow water equations. Then, this topography is slightly modified to obtain new steady solutions, with monotonic PV, that satisfy Ripa’s stability criterion. Application of this procedure shows that modest depressions (elevations) can stabilize cyclones (anticyclones) with small Rossby and large Burger numbers and velocity profiles similar to those observed in mesoscale oceanic vortices. The stabilizing topographic features have radial sizes comparable with that of the vortex (about twice the radius of maximum speed) and maximum vertical size, normalized to the unperturbed fluid depth, from 2 to 3.3 times the Rossby number for the profiles considered. The upper limit corresponds to a Gaussian profile, whereas the lower limit is approached by a velocity profile that is linear inside the vortex core and a cubic polynomial outside. Finally, it is argued that a similar stabilization mechanism holds for two-dimensional (2D) flows, and a method for the construction of stable 2D shallow water vortices over 2D topography is outlined that is analogous to that used for the axisymmetric problem. In the 2D case, however, it is generally not possible to obtain stable equilibria analytically.
Roberto Iacono. Stable Shallow Water Vortices over Localized Topography. Journal of Physical Oceanography 2010, 40, 1143 -1150.
AMA StyleRoberto Iacono. Stable Shallow Water Vortices over Localized Topography. Journal of Physical Oceanography. 2010; 40 (5):1143-1150.
Chicago/Turabian StyleRoberto Iacono. 2010. "Stable Shallow Water Vortices over Localized Topography." Journal of Physical Oceanography 40, no. 5: 1143-1150.