E. Trovatore - Academia.edu (original) (raw)

Papers by E. Trovatore

Research paper thumbnail of Helical shell models for three-dimensional turbulence

Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 1996

In this paper we study a new class of shell models, defined in terms of two complex dynamical var... more In this paper we study a new class of shell models, defined in terms of two complex dynamical variables per shell, transporting positive and negative helicity respectively. The dynamical equations are derived from a decomposition into helical modes of the velocity Fourier components of Navier-Stokes equations (F. Waleffe, Phys. Fluids A 4, 350 (1992)).

Research paper thumbnail of VERIFICATION OF LIMITED-AREA MODELS PRECIPITATION FORECASTS DURING THE MAP-SOP

This contribution presents an extensive study about the performances and forecast skills for rain... more This contribution presents an extensive study about the performances and forecast skills for rain precipitations of several limited area models operating during the Special Observing Period of the Mesoscale Alpine Programme (MAP-SOP, Autumn 1999). Verification is carried out using the updated version of the MAP dataset. Observed data are submitted to a further validation procedure aimed at pointing out defective gauges. As a result, more than 500 stations over a domain surrounding the Alps have been selected. Several statistical indexes widely used in literature are computed using the ECMWF global model as reference. The performances of the limited area models are discussed in detail, paying particular attention to their behavior as a function of rain threshold.

Research paper thumbnail of (1+1)-dimensional turbulence

Physics of Fluids, 1997

A class of dynamical models of turbulence living on a one-dimensional dyadic-tree structure is in... more A class of dynamical models of turbulence living on a one-dimensional dyadic-tree structure is introduced and studied. The models are obtained as a natural generalization of the popular GOY shell model of turbulence. These models are found to be chaotic and intermittent. They represent the first example of (1+1)-dimensional dynamical systems possessing non trivial multifractal properties. The dyadic structure allows to study spatial and temporal fluctuations. Energy dissipation statistics and its scaling properties are studied. Refined Kolmogorov Hypothesis is found to hold.

Research paper thumbnail of Ultrametric Structure of Multiscale Energy Correlations in Turbulent Models

Physical Review Letters, 1997

Title:Ultrametric structure of multiscale energy correlations in turbulent models. Authors: R. Be... more Title:Ultrametric structure of multiscale energy correlations in turbulent models. Authors: R. Benzi, L. Biferale and E. Trovatore Ultrametric structure of the energy cascade process in a dynamical model of turbulence is studied. The tree model we use can be viewed as an approximated one-dimensional truncation of the wavelets resolved Navier-Stokes dynamics. Varying the tree connectiveness, the appearance of a scaling transition in the two-points moments of energy dissipation is detected, in agreement with experimental turbulent data.

Research paper thumbnail of Universal Statistics of Nonlinear Energy Transfer in Turbulent Models

Physical Review Letters, 1996

A class of shell models for turbulent energy transfer at varying the inter-shell separation, λ, i... more A class of shell models for turbulent energy transfer at varying the inter-shell separation, λ, is investigated. Intermittent corrections in the continuous limit of infinitely close shells (λ → 1) have been measured. Although the model becomes, in this limit, non-intermittent, we found universal aspects of the velocity statistics which can be interpreted in the framework of log-poisson distributions, as proposed by She and Waymire (1995, Phys. Rev. Lett. 74, 262). We suggest that non-universal aspects of intermittency can be adsorbed in the parameters describing statistics and properties of the most singular structure. On the other hand, universal aspects can be found by looking at corrections to the monofractal scaling of the most singular structure. Connections with similar results reported in other shell models investigations and in real turbulent flows are discussed.

Research paper thumbnail of Simulating extreme precipitation with a mesoscale forecast model

Meteorology and Atmospheric Physics, 2003

M. Corazza et al

Research paper thumbnail of (1+ 1)-dimensional turbulence

Research paper thumbnail of Nucleon Resonances in Nuclei and Quark Levels

International Journal of Modern Physics E, 1997

ABSTRACT The effect of the nuclear medium on the excitation mechanism of nucleon resonances is in... more ABSTRACT The effect of the nuclear medium on the excitation mechanism of nucleon resonances is investigated in the framework of the constituent quark model (CQM). Calculations of the total strength of the M1 and E1 excitations in a two-nucleon system are performed by means of a two-centre quark potential model in which the intercluster barrier is allowed to vary with the relative distance. The results show that the resonance excitation in the deuteron is not modified with respect to the free nucleon case. In contrast, when the internucleon distance assumes typical nuclear values, the pattern of the quark levels leads to a ~ 10% damping of the D13 resonance, leaving the Δ excitation unaffected, in agreement with the recent photoabsorption measurements.

Research paper thumbnail of Helical shell models for three-dimensional turbulence

Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 1996

In this paper we study a new class of shell models, defined in terms of two complex dynamical var... more In this paper we study a new class of shell models, defined in terms of two complex dynamical variables per shell, transporting positive and negative helicity respectively. The dynamical equations are derived from a decomposition into helical modes of the velocity Fourier components of Navier-Stokes equations (F. Waleffe, Phys. Fluids A 4, 350 (1992)).

Research paper thumbnail of VERIFICATION OF LIMITED-AREA MODELS PRECIPITATION FORECASTS DURING THE MAP-SOP

This contribution presents an extensive study about the performances and forecast skills for rain... more This contribution presents an extensive study about the performances and forecast skills for rain precipitations of several limited area models operating during the Special Observing Period of the Mesoscale Alpine Programme (MAP-SOP, Autumn 1999). Verification is carried out using the updated version of the MAP dataset. Observed data are submitted to a further validation procedure aimed at pointing out defective gauges. As a result, more than 500 stations over a domain surrounding the Alps have been selected. Several statistical indexes widely used in literature are computed using the ECMWF global model as reference. The performances of the limited area models are discussed in detail, paying particular attention to their behavior as a function of rain threshold.

Research paper thumbnail of (1+1)-dimensional turbulence

Physics of Fluids, 1997

A class of dynamical models of turbulence living on a one-dimensional dyadic-tree structure is in... more A class of dynamical models of turbulence living on a one-dimensional dyadic-tree structure is introduced and studied. The models are obtained as a natural generalization of the popular GOY shell model of turbulence. These models are found to be chaotic and intermittent. They represent the first example of (1+1)-dimensional dynamical systems possessing non trivial multifractal properties. The dyadic structure allows to study spatial and temporal fluctuations. Energy dissipation statistics and its scaling properties are studied. Refined Kolmogorov Hypothesis is found to hold.

Research paper thumbnail of Ultrametric Structure of Multiscale Energy Correlations in Turbulent Models

Physical Review Letters, 1997

Title:Ultrametric structure of multiscale energy correlations in turbulent models. Authors: R. Be... more Title:Ultrametric structure of multiscale energy correlations in turbulent models. Authors: R. Benzi, L. Biferale and E. Trovatore Ultrametric structure of the energy cascade process in a dynamical model of turbulence is studied. The tree model we use can be viewed as an approximated one-dimensional truncation of the wavelets resolved Navier-Stokes dynamics. Varying the tree connectiveness, the appearance of a scaling transition in the two-points moments of energy dissipation is detected, in agreement with experimental turbulent data.

Research paper thumbnail of Universal Statistics of Nonlinear Energy Transfer in Turbulent Models

Physical Review Letters, 1996

A class of shell models for turbulent energy transfer at varying the inter-shell separation, λ, i... more A class of shell models for turbulent energy transfer at varying the inter-shell separation, λ, is investigated. Intermittent corrections in the continuous limit of infinitely close shells (λ → 1) have been measured. Although the model becomes, in this limit, non-intermittent, we found universal aspects of the velocity statistics which can be interpreted in the framework of log-poisson distributions, as proposed by She and Waymire (1995, Phys. Rev. Lett. 74, 262). We suggest that non-universal aspects of intermittency can be adsorbed in the parameters describing statistics and properties of the most singular structure. On the other hand, universal aspects can be found by looking at corrections to the monofractal scaling of the most singular structure. Connections with similar results reported in other shell models investigations and in real turbulent flows are discussed.

Research paper thumbnail of Simulating extreme precipitation with a mesoscale forecast model

Meteorology and Atmospheric Physics, 2003

M. Corazza et al

Research paper thumbnail of (1+ 1)-dimensional turbulence

Research paper thumbnail of Nucleon Resonances in Nuclei and Quark Levels

International Journal of Modern Physics E, 1997

ABSTRACT The effect of the nuclear medium on the excitation mechanism of nucleon resonances is in... more ABSTRACT The effect of the nuclear medium on the excitation mechanism of nucleon resonances is investigated in the framework of the constituent quark model (CQM). Calculations of the total strength of the M1 and E1 excitations in a two-nucleon system are performed by means of a two-centre quark potential model in which the intercluster barrier is allowed to vary with the relative distance. The results show that the resonance excitation in the deuteron is not modified with respect to the free nucleon case. In contrast, when the internucleon distance assumes typical nuclear values, the pattern of the quark levels leads to a ~ 10% damping of the D13 resonance, leaving the Δ excitation unaffected, in agreement with the recent photoabsorption measurements.