The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Edwin F. Danielsen - One of the best experts on this subject based on the ideXlab platform.
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Horizontal wind fluctuations in the stratosphere during large-scale cyclogenesis
Journal of Geophysical Research, 1991Co-Authors: K. R. Chan, Edwin F. Danielsen, S. G. Scott, S. W. Bowen, Steven E. Gaines, Leonhard PfisterAbstract:The meteorological measurement system (MMS) on the U-2 Aircraft measured pressure, temperature, and the horizontal wind during a cyclogenesis event over western United States on April 20, 1984. The Aircraft flew above the jet core and traversed in a vertical plane normal to the jet stream axis at four altitudes, making measurements on both the cyclonic and anticyclonic sides of the jet. Horizontal wind data were processed by digital filters to permit analyses of large-scale gradients and of small-scale fluctuations. The mean horizontal wind in the stratosphere decreases monotonically with altitude. Superimposed on the mean stratospheric wind is a perturbation wind vector, which is an elliptically polarized wave with an amplitude of 4 to 10 m s−1 and a vertical wavelength of 2 to 3 km. The perturbation wind vector rotates anticyclonically (clockwise) with altitude and produces alternating advection in the plane of the Aircraft flight path. This differential advection folds surfaces of constant tracer mixing ratio and contributes to the observed tracer laminar structures and inferred cross-jet transport.
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Irreversible transport in the stratosphere by internal waves of short vertical wavelength
Journal of Geophysical Research, 1991Co-Authors: Edwin F. Danielsen, James F. Vedder, Steven E. Gaines, R. Stephen Hipskind, Walter L. Starr, Dieter Kley, K. K. KellyAbstract:The U-2 Aircraft was instrumented and flown in the stratosphere during the Stratosphere-Troposphere Exchange Project's experiments of April 1984 to provide a set of simultaneous measurements by fast responding sensors that would aid in the identification of the modes of cross-jet transport. The measurements confirm the preexperimental deductions that transport is dominated by waves, not by large-scale circulations. Monotonic gradients of trace constituents normal to the jet axis, with upper stratospheric tracers increasing poleward and tropospheric tracers increasing equatorward, are augmented by large-scale confluence as the jet intensifies during cyclogenesis. These gradients are rotated, intensified, and significantly increased in area as their mixing ratio surfaces are folded by the differential transport of a very low frequency, transverse wave. The quasi-horizontal transport produces a laminar structure with stable layers rich in upper stratospheric tracers alternating vertically with less stable layers rich in tropospheric tracers. The transport proceeds toward irreversibility as higher frequency, shear-gravity waves extend the folding to smaller horizontal scales. It becomes irreversible when these short waves actually fold the isentropic surfaces and small-scale mixing develops. The progression to higher wave numbers is a discrete, not a continuous, cascade with major gaps in the observed horizontal wavelengths. The wave modes are identified by matching the observed amplitudes and phases against those obtained by linear perturbation theory. Prior to mixing, the wave-generated perturbations maintain the correlations produced by advecting the larger-scale mean gradients; thus the high resolution measurements support the linear turbulence closure assumption.
K. K. Kelly - One of the best experts on this subject based on the ideXlab platform.
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Irreversible transport in the stratosphere by internal waves of short vertical wavelength
Journal of Geophysical Research, 1991Co-Authors: Edwin F. Danielsen, James F. Vedder, Steven E. Gaines, R. Stephen Hipskind, Walter L. Starr, Dieter Kley, K. K. KellyAbstract:The U-2 Aircraft was instrumented and flown in the stratosphere during the Stratosphere-Troposphere Exchange Project's experiments of April 1984 to provide a set of simultaneous measurements by fast responding sensors that would aid in the identification of the modes of cross-jet transport. The measurements confirm the preexperimental deductions that transport is dominated by waves, not by large-scale circulations. Monotonic gradients of trace constituents normal to the jet axis, with upper stratospheric tracers increasing poleward and tropospheric tracers increasing equatorward, are augmented by large-scale confluence as the jet intensifies during cyclogenesis. These gradients are rotated, intensified, and significantly increased in area as their mixing ratio surfaces are folded by the differential transport of a very low frequency, transverse wave. The quasi-horizontal transport produces a laminar structure with stable layers rich in upper stratospheric tracers alternating vertically with less stable layers rich in tropospheric tracers. The transport proceeds toward irreversibility as higher frequency, shear-gravity waves extend the folding to smaller horizontal scales. It becomes irreversible when these short waves actually fold the isentropic surfaces and small-scale mixing develops. The progression to higher wave numbers is a discrete, not a continuous, cascade with major gaps in the observed horizontal wavelengths. The wave modes are identified by matching the observed amplitudes and phases against those obtained by linear perturbation theory. Prior to mixing, the wave-generated perturbations maintain the correlations produced by advecting the larger-scale mean gradients; thus the high resolution measurements support the linear turbulence closure assumption.
Steven E. Gaines - One of the best experts on this subject based on the ideXlab platform.
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Horizontal wind fluctuations in the stratosphere during large-scale cyclogenesis
Journal of Geophysical Research, 1991Co-Authors: K. R. Chan, Edwin F. Danielsen, S. G. Scott, S. W. Bowen, Steven E. Gaines, Leonhard PfisterAbstract:The meteorological measurement system (MMS) on the U-2 Aircraft measured pressure, temperature, and the horizontal wind during a cyclogenesis event over western United States on April 20, 1984. The Aircraft flew above the jet core and traversed in a vertical plane normal to the jet stream axis at four altitudes, making measurements on both the cyclonic and anticyclonic sides of the jet. Horizontal wind data were processed by digital filters to permit analyses of large-scale gradients and of small-scale fluctuations. The mean horizontal wind in the stratosphere decreases monotonically with altitude. Superimposed on the mean stratospheric wind is a perturbation wind vector, which is an elliptically polarized wave with an amplitude of 4 to 10 m s−1 and a vertical wavelength of 2 to 3 km. The perturbation wind vector rotates anticyclonically (clockwise) with altitude and produces alternating advection in the plane of the Aircraft flight path. This differential advection folds surfaces of constant tracer mixing ratio and contributes to the observed tracer laminar structures and inferred cross-jet transport.
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Irreversible transport in the stratosphere by internal waves of short vertical wavelength
Journal of Geophysical Research, 1991Co-Authors: Edwin F. Danielsen, James F. Vedder, Steven E. Gaines, R. Stephen Hipskind, Walter L. Starr, Dieter Kley, K. K. KellyAbstract:The U-2 Aircraft was instrumented and flown in the stratosphere during the Stratosphere-Troposphere Exchange Project's experiments of April 1984 to provide a set of simultaneous measurements by fast responding sensors that would aid in the identification of the modes of cross-jet transport. The measurements confirm the preexperimental deductions that transport is dominated by waves, not by large-scale circulations. Monotonic gradients of trace constituents normal to the jet axis, with upper stratospheric tracers increasing poleward and tropospheric tracers increasing equatorward, are augmented by large-scale confluence as the jet intensifies during cyclogenesis. These gradients are rotated, intensified, and significantly increased in area as their mixing ratio surfaces are folded by the differential transport of a very low frequency, transverse wave. The quasi-horizontal transport produces a laminar structure with stable layers rich in upper stratospheric tracers alternating vertically with less stable layers rich in tropospheric tracers. The transport proceeds toward irreversibility as higher frequency, shear-gravity waves extend the folding to smaller horizontal scales. It becomes irreversible when these short waves actually fold the isentropic surfaces and small-scale mixing develops. The progression to higher wave numbers is a discrete, not a continuous, cascade with major gaps in the observed horizontal wavelengths. The wave modes are identified by matching the observed amplitudes and phases against those obtained by linear perturbation theory. Prior to mixing, the wave-generated perturbations maintain the correlations produced by advecting the larger-scale mean gradients; thus the high resolution measurements support the linear turbulence closure assumption.
Walter L. Starr - One of the best experts on this subject based on the ideXlab platform.
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Irreversible transport in the stratosphere by internal waves of short vertical wavelength
Journal of Geophysical Research, 1991Co-Authors: Edwin F. Danielsen, James F. Vedder, Steven E. Gaines, R. Stephen Hipskind, Walter L. Starr, Dieter Kley, K. K. KellyAbstract:The U-2 Aircraft was instrumented and flown in the stratosphere during the Stratosphere-Troposphere Exchange Project's experiments of April 1984 to provide a set of simultaneous measurements by fast responding sensors that would aid in the identification of the modes of cross-jet transport. The measurements confirm the preexperimental deductions that transport is dominated by waves, not by large-scale circulations. Monotonic gradients of trace constituents normal to the jet axis, with upper stratospheric tracers increasing poleward and tropospheric tracers increasing equatorward, are augmented by large-scale confluence as the jet intensifies during cyclogenesis. These gradients are rotated, intensified, and significantly increased in area as their mixing ratio surfaces are folded by the differential transport of a very low frequency, transverse wave. The quasi-horizontal transport produces a laminar structure with stable layers rich in upper stratospheric tracers alternating vertically with less stable layers rich in tropospheric tracers. The transport proceeds toward irreversibility as higher frequency, shear-gravity waves extend the folding to smaller horizontal scales. It becomes irreversible when these short waves actually fold the isentropic surfaces and small-scale mixing develops. The progression to higher wave numbers is a discrete, not a continuous, cascade with major gaps in the observed horizontal wavelengths. The wave modes are identified by matching the observed amplitudes and phases against those obtained by linear perturbation theory. Prior to mixing, the wave-generated perturbations maintain the correlations produced by advecting the larger-scale mean gradients; thus the high resolution measurements support the linear turbulence closure assumption.
R. Stephen Hipskind - One of the best experts on this subject based on the ideXlab platform.
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Irreversible transport in the stratosphere by internal waves of short vertical wavelength
Journal of Geophysical Research, 1991Co-Authors: Edwin F. Danielsen, James F. Vedder, Steven E. Gaines, R. Stephen Hipskind, Walter L. Starr, Dieter Kley, K. K. KellyAbstract:The U-2 Aircraft was instrumented and flown in the stratosphere during the Stratosphere-Troposphere Exchange Project's experiments of April 1984 to provide a set of simultaneous measurements by fast responding sensors that would aid in the identification of the modes of cross-jet transport. The measurements confirm the preexperimental deductions that transport is dominated by waves, not by large-scale circulations. Monotonic gradients of trace constituents normal to the jet axis, with upper stratospheric tracers increasing poleward and tropospheric tracers increasing equatorward, are augmented by large-scale confluence as the jet intensifies during cyclogenesis. These gradients are rotated, intensified, and significantly increased in area as their mixing ratio surfaces are folded by the differential transport of a very low frequency, transverse wave. The quasi-horizontal transport produces a laminar structure with stable layers rich in upper stratospheric tracers alternating vertically with less stable layers rich in tropospheric tracers. The transport proceeds toward irreversibility as higher frequency, shear-gravity waves extend the folding to smaller horizontal scales. It becomes irreversible when these short waves actually fold the isentropic surfaces and small-scale mixing develops. The progression to higher wave numbers is a discrete, not a continuous, cascade with major gaps in the observed horizontal wavelengths. The wave modes are identified by matching the observed amplitudes and phases against those obtained by linear perturbation theory. Prior to mixing, the wave-generated perturbations maintain the correlations produced by advecting the larger-scale mean gradients; thus the high resolution measurements support the linear turbulence closure assumption.
