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R. Avila and S. S. Raza

regions of low turbulence, except the models of Avila (1997) and Riddle et al. (2004) . In this paper, the dispersion of particles in a neutral planetary boundary layer is presented. The mean horizontal wind velocities u and υ that promote the dispersion of particles were previously obtained by solving a numerical model for the turbulent flow in a horizontally homogeneous atmosphere, assuming an equilibrium between the Coriolis force, pressure, and friction forces ( Avila 1997 ). Avila (1997

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T. Cherubini, S. Businger, R. Lyman, and M. Chun

1. Introduction Atmospheric turbulence is a key challenge in ground-based astronomy because it dramatically impacts the angular resolution of a telescope. Small-scale temperature and moisture fluctuations in the atmosphere result in fluctuations of the refractive index. The wave front of radiation traveling through the atmosphere changes as it encounters inhomogeneities in the refractive index, degrading optical image quality. The intensity of the turbulent fluctuations of the atmospheric

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Wayne F. Feltz, William L. Smith, Robert O. Knuteson, Henry E. Revercomb, Harold M. Woolf, and H. Ben Howell

Introduction In recent years it has become increasingly important to characterize the thermodynamic state of the earth’s planetary boundary layer (PBL) at higher temporal resolution than is currently possible with radiosondes. Improved meteorological model data assimilation schemes used in mesoscale models have created a necessity for frequent updates of primary meteorological parameters ( Benjamin et al. 1995 ). In situ commercial aircraft measurements ( Fleming 1996 ) and ground-based wind

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Pedro A. Jiménez and Jimy Dudhia

bias exists when comparing model results using wind stress formulations valid for the open ocean with wind profile data over the first 100 m of the atmosphere in shallow waters and that increasing the surface roughness length is sufficient to reconcile model results with the observed wind profile. We focus on just one aspect—depth—of the complex problem related to drag over shallow-water surfaces. We do not consider other aspects, such as fetch or wave age, that modulate the drag over shallow

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Dan Lubin and Paul G. Weber

The bidirectional reflectance distribution function (BRDF) of an overcast atmosphere above an ocean surfacehas been calculated as a function of wavelength using a discrete-ordinates radiative transfer model. This planeparallel BRDF appears qualitatively similar to the empirically derived angular dependence models from theEarth Radiation Budget Experiment. But when these two different BRDFs are used to estimate net shortwaveflux at the ocean surface, discrepancies of 20-60 W m-2 can occur between

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C. G. Justus, R. G. Roper, Arthur Woodrum, and O. E. Smith

synoptic, diurnal, planetary wave and gravity wavevariations. The monthly mean models consist of: (i) NASA's four dimensional worldwide model, developedby Environmental Research and Technology, for height, latitude, and longitude dependent monthly meansfrom the surface to 25 kin; and (ii) a newly developed latitude-longitude dependent model which is an extension of the Groves latitude dependent model for the region between 25 and 90 km. The Jacchia 1970model is used above 90 km and is faired with the

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J. Murray Mitchell Jr.

reflected by the surface)A~ albedo of earth-atmosphere system (local "planetary" albedo), omitting the contri bution of cloudsa measure of total absorption of solar radiation by aerosol, relative to Sob measure of total backscatter of solar radiation by aerosol that escapes through top of aerosol layer, relative to SoC sensibl.e heating of earth's surface by solar radiation, as a fraction of total (sensible plus latent) solar heating of

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G. A. Herbert, W. A. Hass, and J. K. Angell

the fall and winter of 1966-67. A computer program, which generates maximumoverpressure values for a horizontally stratified real atmosphere, is tested against the mean observed overpressure on the grid and is shown to be in error by an average of 10~ when the maximum observed overpressure is derived from the positive impulse area. The pressure traces are grouped into three categories, sothat "spiked" signatures, which constitute the largest deviation from the mean, may be studied as a functionof

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Xia Sun, Heather A. Holmes, and Hui Xiao

conditions, emissions, and atmospheric chemistry all impact the air quality modeling uncertainties ( Gilliam et al. 2015 ). Accurate meteorological simulations cannot be achieved without correct representation of the land–atmosphere interactions, which are the major driver in the surface hydrological and energy cycles. Because of this fact, the land–atmosphere interactions impact the near-surface meteorological conditions and modulate clouds and precipitation ( Santanello et al. 2018 ). Simulations using

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Beth Chertock, Robert Frouin, and Catherine Gautier

) ABSTRACT The present study constitutes the generation and validation of the first satellite-based, long-term record ofsurface solar irradiance over the global oceans. The record is generated using Nimbus-7 earth radiation budget(ERB) wide-field-of-view (WFOV) planetary-albedo data as input to a numerical algorithm designed and implemented for this study based on radiative transfer theory. Net surface solar irradiance is obtained by subtractingthe solar radiation reflected by the ocean-atmosphere

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