The Experts below are selected from a list of 12207 Experts worldwide ranked by ideXlab platform

Arshad M. Mirza - One of the best experts on this subject based on the ideXlab platform.

W. Masood - One of the best experts on this subject based on the ideXlab platform.

H Biglari - One of the best experts on this subject based on the ideXlab platform.

  • theory of dissipative trapped ion Convective Cell turbulence
    Physical Review Letters, 1990
    Co-Authors: P H Diamond, H Biglari
    Abstract:

    The nonlinear dynamics of dissipative trapped-ion Convective Cells in broadband turbulence is analyzed. Saturation is achieved by both local {ital and} nonlocal transfer of spectral energy from unstable long-wavelength trapped-ion fluctuations to shear-damped moderate-wavelength trapped-electron modes. In particular, contrary to previous studies, it is shown conclusively that no long-wavelength condensation of fluctuation energy is possible. The transport level associated with these structures is therefore moderate and not catastrophic (Bohm-like), as conventionally believed.

P H Diamond - One of the best experts on this subject based on the ideXlab platform.

  • energy transfer dynamics of dissipative trapped ion Convective Cell turbulence
    Physics of fluids. B Plasma physics, 1992
    Co-Authors: D E Newman, P W Terry, P H Diamond
    Abstract:

    The properties of the spectral energy transfer for a two‐dimensional fluid representation of dissipative trapped ion Convective Cell turbulence are studied numerically using a spectral method. It is established that the spectral energy flow is from long to short wavelength, as governed (under the dynamics of the E×B nonlinearity) by a single quadratic invariant, the energy. This flow is correctly predicted by equilibrium statistical mechanics, as is the equilibrium spectrum. Examining the locality of energy flow, strong nonlocal energy transfer is observed, a process that efficiently transfers the energy of a mode across the spectrum in a correlation time. This transfer process deviates dramatically from the canonical self‐similar cascade dynamics of Kolmogorov that typifies the cascade of two‐ and three‐dimensional Navier–Stokes and Hasegawa–Mima drift wave turbulence. Anisotropy of the spectral transfer dynamics is also observed.

  • theory of dissipative trapped ion Convective Cell turbulence
    Physical Review Letters, 1990
    Co-Authors: P H Diamond, H Biglari
    Abstract:

    The nonlinear dynamics of dissipative trapped-ion Convective Cells in broadband turbulence is analyzed. Saturation is achieved by both local {ital and} nonlocal transfer of spectral energy from unstable long-wavelength trapped-ion fluctuations to shear-damped moderate-wavelength trapped-electron modes. In particular, contrary to previous studies, it is shown conclusively that no long-wavelength condensation of fluctuation energy is possible. The transport level associated with these structures is therefore moderate and not catastrophic (Bohm-like), as conventionally believed.

Jean-pierre Cammas - One of the best experts on this subject based on the ideXlab platform.

  • Rossby wave interactions with Mediterranean and subtropical latitudes
    Meteorology and Atmospheric Physics, 2010
    Co-Authors: Jean-pierre Cammas
    Abstract:

    The downstream influence of a Rossby wave on weather conditions in the Mediterranean and North Africa is studied. The objective is to gain a better understanding of the atmospheric processes in these regions and to improve their quantification. The emphasis is placed on high-impact weather events to improve numerical forecasts and warnings about these hazardous weather phenomena. For this purpose, 4 days from 5 to 8 February 1997 are used to investigate both a Mediterranean low and a subtropical African Convective situation. Sensitivity studies, using a potential vorticity inversion tool associated with the French atmospheric model ARPEGE, are presented. The Mediterranean surface low under study is shown to be associated with the mid-latitude upper level potential vorticity anomaly, itself associated with a Rossby wave. A subtropical Convective Cell is shown to be related to upward vertical motions associated with a cut-off low; this cut-off low coming from a mid-latitude Rossby wave.

  • Rossby wave interactions with Mediterranean and subtropical latitudes
    Meteorology and Atmospheric Physics, 2010
    Co-Authors: Jean-pierre Cammas
    Abstract:

    The downstream influence of a Rossby wave on weather conditions in the Mediterranean and North Africa is studied. The objective is to gain a better understanding of the atmospheric processes in these regions and to improve their quantification. The emphasis is placed on high-impact weather events to improve numerical forecasts and warnings about these hazardous weather phenomena. For this purpose, 4 days from 5 to 8 February 1997 are used to investigate both a Mediterranean low and a subtropical African Convective situation. Sensitivity studies, using a potential vorticity inversion tool associated with the French atmospheric model ARPEGE, are presented. The Mediterranean surface low under study is shown to be associated with the mid-latitude upper level potential vorticity anomaly, itself associated with a Rossby wave. A subtropical Convective Cell is shown to be related to upward vertical motions associated with a cut-off low; this cut-off low coming from a mid-latitude Rossby wave.