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Norman A. Phillips

TIROS-N data for 21 October 1979 indicate a stronger jet and cyclone vortex at 250 mb in the eastern Pacific than is suggested by forecast continuity and aircraft winds. NOAA-6 data for 29 January 1980 illustrates the problem of microwave temperature retrievals that are too low when precipitation is present. A preliminary test for the latter is outlined and recommended for users of the GWE Level lib satellite data.

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Norman A. Phillips

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Norman A. Phillips

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Variational analysis with a geostrophic constraint is used to estimate a critical accuracy for a satellite lidar wind measuring system. This accuracy is such that the combination of satellite winds with satellite temperatures can produce analyses with an accuracy equal to that obtained from a rawinsonde network. An important assumption allowing this estimate to be made is that the satellite wind and temperature measurements are made with a spatial density equal to that of the rawinsonde network.

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Norman A. Phillips

A linear dynamical prediction model is combined with a linear analysis scheme to give a formula for the expected squared forecast error, as a function of space and time, given a knowledge of observational error covariance and spectrum of the true field. The formula is applied with a two-layer geostrophic model to estimate the maximum impact of tropospheric temperatures derived from satellite radiances over oceanic areas on the accuracy of 500 mb forecasts over North America. The results show a positive impact if the observations are analyzed by an unrealistically efficient optimum interpolation method, but they show a negative impact at all but the smallest satellite error values if the observations are analyzed by a method that ignores observational errors. Eight conclusions are reached concerning routine numerical forecasts and the First GARP Global Experiment.

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Norman A. Phillips

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The Baer-Tribbia nonlinear modal initialization method implies that large-scale meteorological analyses should focus on analysis of slow mode fields. An idealized multi-variate optimum interpolation analysis is shown to produce grid point results that contain only slow modes. Variational analysis with a slow mode constraint is therefore unnecessary.

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Norman A. Phillips

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Norman A. Phillips

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Norman A. Phillips

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An experimental colocation and statistical regression scheme is used to verify the hypothesis that large consistent mean errors in the cloudy oceanic satellite temperature retrievals north of 30°N from TIROS-N are due to a continental bias in the statistical colocation base. Sea surface water temperature is a useful predictor for these conditions. Significant improvement in these retrievals is possible. However, much of this improvement requires the presence in the colocation base of the, mid-ocean radiosondes from the ocean weather ships.

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Norman A. Phillips

Inertia circle motion is a familiar concept demonstrating the behavior of a horizontally moving particle on the rotating earth in response to the Coriolis force. Three dynamical principles valid in nonrotating space are used to explain the principal properties of this motion without the need for solving differential equations. The motion is an oscillation about a central latitude selected by the particle's angular momentum, in which the restoring force is set by the relative magnitudes of the poleward attraction of gravity and the equatorward attraction of the centrifugal force as the particle oscillates about the central latitude.

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Norman A. Phillips
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