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Ronald B. Smith
and
Idar Barstad

algebra, we obtain an expression for the Fourier transform of the precipitation distribution in terms of the specified source function. In (5) , ( k, l ) are the components of the horizontal wavenumber vector and σ = Uk + Vl is the intrinsic frequency (see also Smith 2003b for examples of solving the advection equation with Fourier methods). The transform (5) can be inverted to obtain the precipitation distribution P ( x, y ) using According to (5) , (6) , precipitation is

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Elizabeth A. Jacobson
and
E. Philip Krider

region of highthunderstorm frequency which has received little previous study. In this paper, we present and analyzetypical electric fields produced by thunderstorms andlightning at KSC. Data were obtained during twostorms in 1973 using a single field mill and for a numberof storms in 1974 using 21 instruments.2.InstrumentationA map showing the locations of the field mill sitesat KSC is given in Fig. 1. Each field mill containseight vertically oriented stator sectors which are alternately covered and

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Xun Zhu

found that the algebraic approximation of the saturated vertical wavenumber spectrum of horizontal winds, F(/z), cab be written as ~/z_3(0 2.5 F(/~)where/~ is the dimensionless vertical wavenumber, and 0 is a parameter measuring the ratio of the dynamiceffect to the radiative effect on the dissipation. The theory predicts the widely cited -3 power law for both smalland large vertical

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B. G. Hunt

). Thus Lorenz has used quadratic and cubic algebraic equations to illustrate nonlinear behavior whichhe related to certain aspects of the variability of theEarth's climate. Recently, Gordon and Hunt (1986)have suggested that "local" droughts obtained in a tenyear atmospheric simulation using a general circulationmodel are a consequence of nonlinear, dynamical interactions, suggesting a potentially important role forthese interactions in climatic fluctuations. The presence of nonlinearities in the

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E. E. Gossard
and
W. B. Sweezy

impedance equation, which isthe frequency relative to the mean airstream at thepoint where the sensors are located. Therefore, toobtain k from f, it is necessary to add algebraically thecomponent of the airstream velocity to the intrinsicwave velocity, w/k, and use the wave velocity relativeto the ground in the transformation. Thus, if ~ is thecomponent of mean velocity in the direction of wavepropagation, 2~r k = (co/k) q-~f'where, in general, w/k will itself be a function

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Rudolph W. Preisendorfer
and
Tim P. Barnett

evaluation of the performance of a GCM.2. Overview of tests The tests we develop here are based on a set ofthree statistics carved out of a single measure of separation between two data sets (D and M) given to usin the form of n x p matrices. This measure of separation of D and M is the square of the Euclideandistance (the norm) between the two sets when theyare represented as two points in a Euclidean space(End,) ofdimensi0n no. By an algebraic rearrangement,the expression for the norm can be

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Steven C. Sherwood

diagnostic water vapor simulations during this month ( Sherwood 1996b ). The responses shown later are not sensitive to moderate changes in the base state, so the particular choice of month is not important. The horizontal coverage assigned to the model, which includes the tropical Pacific and Indian Oceans from 24°N to 24°S latitude, is indicated in Fig. 2 . The two regions are divided according to the isotherm of median SST (300.5 K). Given in the lower panel of this figure is a map of outgoing

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Youtong Zheng
,
Daniel Rosenfeld
, and
Zhanqing Li

that cloud-base updraft speed in cloud should be consistent with the updraft speed just below the cloud base ( Kollias et al. 2001 ). If our technique is valid, cloud-base updraft speed W cb calculated using Eq. (6) with inputs from our technique should be in agreement with the in-cloud W cb that can be obtained by selecting cloudy pixels at cloud base by increasing the SNR threshold so that only cloudy pixels remain. Comparison of these two cloud-base updraft speeds shows good agreement

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Zuzana Procházková
,
Christopher G. Kruse
,
M. Joan Alexander
,
Lars Hoffmann
,
Julio T. Bacmeister
,
Laura Holt
,
Corwin Wright
,
Kaoru Sato
,
Sonja Gisinger
,
Manfred Ern
,
Markus Geldenhuys
,
Peter Preusse
, and
Petr Šácha

-dominated interval for smaller wavelengths. We will refer to the high-pass filter method using cutoff specified at each time step (again apart from the initial and final time steps because of spectrum smoothing) by this algorithm as the divergence dominated method. e. S3D method For comparison, we also derive GWD estimates using the widely used S3D method for GW detection ( Lehmann et al. 2012 ; Stephan et al. 2019 ; Preusse et al. 2014 ; Ern et al. 2017 ; Krisch et al. 2017 ; Strube et al. 2021

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Qingfang Jiang
,
James D. Doyle
, and
Ronald B. Smith

many studies (e.g., Durran 1986 ; Wurtele et al. 1996 ; Doyle and Smith 2003 ). In these studies, the ground surface was usually treated as a perfect reflector. However, in a recent case study of gravity waves sampled over Monte Blanc during the Mesocale Alpine Program (MAP), Smith et al. (2002) noticed that, while the strong wind and weak stability in the upper troposphere forced the wave into a decaying evanescent state, no lee-wave pattern was observed. To interpret this paradox, they

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