A Comparison of Quasigeostrophic and Nonquasigeostrophic Vertical Motions for a Model-simulated Rapidly Intensifying Marine Extratropical Cyclone

Pauley, Patricia M.; Nieman, Steven J.

doi:10.1175/1520-0493(1992)120<1108:acoqan>2.0.co;2

Cited by 27 publications

(29 citation statements)

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“…According to Krishnamurti (1968) and Pauley and Nieman (1992), the boundary effect (providing little insight) on the inside area of the model domain has to be removed in the calculation of the contributions of the individual internal forcing terms. This can be accomplished by using the zero lateral boundary conditions (Krishnamurti, 1968;Pauley and Nieman, 1992) since the boundary effect on the inside area is caused by the iteration-induced propagation of the boundary values. Be aware that the iteration-induced signal propagation of a dominant system might mask the signal of a nearby relatively weak system of interest.…”

Section: Derivation Of a Complete Geopotential Numerical Model And Scmentioning

confidence: 99%

“…The ith internal forcing effect (i.e. i ) attributed to the ith internal forcing f i is obtained from solving the Poisson equation ∇ 2 2 i = f i with zero lateral boundary conditions (in order to remove the boundary effect on the inside area (Krishnamurti, 1968;Pauley and Nieman, 1992) deviation from area ). The reason for using the symbol DFRM is merely that the 'deviation from the regional mean' is easier to follow than the 'deviation from the boundary effect'.…”

Section: The Systematic Information Behind the Forcing Termsmentioning

confidence: 99%

“…157 and 165-166), modified, and then used in numerical and diagnostic studies (e.g. Tsou et al, 1987;Pauley and Nieman, 1992;Tan and Curry, 1993;Räisänen, 1995). However, the magnitudes of the calculated ∂ /∂t were much larger than those of the observed ∂ /∂t owing to the fact that the model outputs were the instantaneous ∂ /∂t while the observations were the 24-hour averaged ∂ /∂t (Tan and Curry, 1993).…”

Section: Introductionmentioning

confidence: 99%

“…165-166) and the non-quasigeostrophic (non-QG) ω equation (e.g. Pauley and Nieman, 1992;Räisänen, 1995), we have to assume the ratio of the inertial stability parameter (ζ + f ) to the static stability parameter (σ ) is positive for the ∂ /∂t and ω equations to remain elliptic in form. This assumption might encumber the application of the ∂ /∂t and ω models to the global case in reality because not only could static instability σ < 0 (due to cold air masses rushing over warm seas) and jet-induced inertial instability (ζ + f ) < 0 be observed but also neutral stability σ = 0 in the cold domes.…”

Section: Introductionmentioning

confidence: 99%

“…In order to get convergent output from the ∂ /∂t and ω models, we have to break down the conservation laws of geophysical fluid dynamics and smooth out the observed σ 0 and (ζ + f ) < 0 artificially through modifying the observed 2068 Z. YUAN ET AL. data (Pauley and Nieman, 1992;Tan and Curry, 1993;Räisänen, 1995).…”

Section: Introductionmentioning

confidence: 99%

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The derivation of a numerical diagnostic model for the forcing of the geopotential

Zhang

Cheng

et al. 2008

Quart J Royal Meteoro Soc

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ABSTRACT:Simply applying the divergence operator to the horizontal velocity equation in spherical-isobaric coordinates yields a more solvable linear geopotential equation (than the geopotential tendency and the omega equations) for diagnosing the geopotential and its anomalies responsible for global floods and droughts. This geopotential model is freed from the zerodenominator problem caused by the observed neutral stability which affects the geopotential tendency and omega equations. The geopotential equation's forcing terms 2-5 (the direct operation results of the horizontal advection term in the velocity equation) can identify the synoptic signals mixed up by the classical divergence equation's quadratic and Jacobian terms (the manipulated results of the above terms 2-5). Solving this geopotential equation with the successive-over-relaxation method and the neutral stability as calculated from the reanalysis data produces reasonably good reconstructions of the global and local geopotential fields. The additional advantages of the present geopotential model over the geopotential tendency, omega and divergence models are that the geopotential model reveals and explains the following mechanisms which received less attention in previous studies. (1) The saddle patterns favour the high systems. (2) The equatorial easterlies favour the low systems. (3) The contributions of ageostrophic processes associated with jets and saddle flows to the transitions of weather patterns might be overlooked by the geopotential tendency model in which neutral stability and static instability in cold domes as well as jet-induced inertial instability are smoothed out artificially.

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Section: Derivation Of a Complete Geopotential Numerical Model And Scmentioning

confidence: 99%

Section: The Systematic Information Behind the Forcing Termsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The derivation of a numerical diagnostic model for the forcing of the geopotential

Zhang

Cheng

et al. 2008

Quart J Royal Meteoro Soc

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Near‐surface strong winds in a marine extratropical cyclone: acceleration of the winds and the importance of surface fluxes

Slater

Schultz

Vaughan

2016

Quart J Royal Meteoro Soc

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A rapidly developing extratropical cyclone named Tini brought strong winds to Ireland and the United Kingdom on 12 February 2014. A mesoscale-model simulation is used to analyze the development of the strong winds through the terms in the horizontal momentum equation. The maximum of near-surface wind speed equatorward of the cyclone was composed of two different airstreams that underwent different paths to acceleration. First, horizontally moving air in the cold conveyor belt was accelerated by the along-flow pressure gradient force but was decelerated by friction. Second, descending air accelerated into the eastern end of the maximum of near-surface wind speed and was associated, in part, with a sting jet, caused by the increasing along-flow horizontal pressure gradient force at lower levels. When this descending air entered the boundary layer, it too was decelerated by surface friction. Surface fluxes of heat and moisture were necessary to destabilize and deepen the boundary layer, allowing mixing of the strongest winds from the free troposphere down to the surface. A simulation with the surface fluxes turned off during cyclogenesis showed a more stable boundary layer around the bent-back front, which inhibited the strongest winds from reaching the surface. The descent of the sting-jet air was associated with a maximum in quasigeostrophic omega, which consisted of both synoptic-scale and mesoscale descent, the latter associated with frontolysis occurring at the end of the bent-back front. Thus, the near-surface wind maximum was created by the synoptic-scale and mesoscale dynamics, whereas localized moist processes were negligible.

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On the forced tangentially-averaged radial-vertical circulation within vortices. Part II: The transformation of Tropical Storm Haima (2004)

Qian

Chen

Qiaoqian³

et al. 2011

Adv. Atmos. Sci.

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A Comparison of Quasigeostrophic and Nonquasigeostrophic Vertical Motions for a Model-simulated Rapidly Intensifying Marine Extratropical Cyclone

Cited by 27 publications

References 0 publications

The derivation of a numerical diagnostic model for the forcing of the geopotential

The derivation of a numerical diagnostic model for the forcing of the geopotential

Near‐surface strong winds in a marine extratropical cyclone: acceleration of the winds and the importance of surface fluxes

On the forced tangentially-averaged radial-vertical circulation within vortices. Part II: The transformation of Tropical Storm Haima (2004)

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