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  • Author or Editor: HAROLD J. SMITH x
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CARL M. BOETTGER and HAROLD J. SMITH

Abstract

During the period of the Nashville Community Air Pollution Study, the Weather Bureau at Nashville, Tenn., forecasted air pollution to be one of three levels for the following day. The forecast method was most reliable during the winter season when pollution ranges were high. Discrimination of air pollution levels can undoubtedly be improved through experience and further studies, and the method is general enough to be used at other locales.

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Fred J. Kopp, Paul L. Smith, and Harold D. Orville

Abstract

A mathematical scheme is developed to compute the gradients of observations taken over complex terrain. The method is applied to an artificial example to demonstrate the scheme. An application is made to surface pressure observations between Little Rock, Arkansas, and Amarillo, Texas. Divergence computations are made with the scheme using observed wind data over the Black Hills of South Dakota.

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John J. Bates, William L. Smith, Gary S. Wade, and Harold M. Woolf

A technique for interactively producing sea-surface temperatures (SST) from VAS multispectral radiance observations and displaying the derived field is outlined. High-resolution composite images using data from several times per day and over a several-day period are shown to illustrate how the technique is applied. The cloud-screening procedures are interactive so that they can be optimized to eliminate the effects of small clouds while still retrieving a sufficient number of SSTs to permit analysis of mesoscale flow features. SST-image products have been produced in real time at the University of Wisconsin as part of the genesis of Atlantic lows experiment (GALE) and as part of the NOAA operational VAS assessment (NOVA) program.

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Paul L. Smith, Arnett S. Dennis, Bernard A. Silverman, Arlin B. Super, Edmond W. Holroyd III, William A. Cooper, Paul W. Mielke Jr., Kenneth J. Berry, Harold D. Orville, and James R. Miller Jr.

Abstract

The design and conduct of HIPLEX-1, a randomized seeding experiment carried out on small cumulus congestus clouds in eastern Montana, are outlined. The seeding agent was dry ice, introduced in an effort to produce microphysical effects, especially the earlier formation of precipitation in the seeded clouds. The earlier formation was expected to increase both the probability and the amount of precipitation from those small clouds with short lifetimes. The experimental unit selection procedure, treatment and randomization procedures, the physical hypothesis, measurement procedures and the response variables defined for the experiment are discussed. Procedures used to calculate the response variables from aircraft and radar measurements are summarized and the values of those variables for the 20 HIPLEX-1 test cases from 1979 and 1980 are tabulated.

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Bruce A. Boe, Jeffrey L. Stith, Paul L. Smith, John H. Hirsch, John H. Helsdon Jr., Andrew G. Detwiler, Harold D. Orville, Brooks E. Mariner, Roger F. Reinking, Rebecca J. Meitín, and Rodger A. Brown

The North Dakota Thunderstorm Project was conducted in the Bismarck, North Dakota, area from 12 June through 22 July 1989. The project deployed Doppler radars, cloud physics aircraft, and supporting instrumentation to study a variety of aspects of convective clouds. These included transport and dispersion; entrainment; cloud-ice initiation and evolution; storm structure, dynamics, and kinematics; atmospheric chemistry; and electrification.

Of primary interest were tracer experiments that identified and tracked specific regions within evolving clouds as a means of investigating the transport, dispersion, and activation of ice-nucleating agents as well as studying basic transport and entrainment processes. Tracers included sulfur hexafluoride (SF6), carbon monoxide, ozone, radar chaff, and silver iodide.

Doppler radars were used to perform studies of all scales of convection, from first-echo cases to a mesoscale convective system. An especially interesting dual-Doppler study of two splitting thunderstorms has resulted.

The objectives of the various project experiments and the specific facilities employed are described. Project highlights and some preliminary results are also presented.

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