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K. H. Jehn

Microwave refractive-index distributions in the lower atmosphere through the various stages of development of the winter Texas-West Gulf of Mexico cyclone are presented by means of “composite” surface and 850-mb analyses, along with vertical atmospheric cross-sections. The resulting patterns constitute a partial and preliminary synoptic climatology of the subject phenomenon.

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K. H. Jehn
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K. H. Jehn

Microwave refractive-index distributions in the lower atmosphere through the various stages of development of the winter cold outbreak in the central United States are presented by means of “composite” surface and 850-mb analyses, along with vertical atmospheric cross-sections. The resulting patterns constitute a partial and preliminary synoptic climatology of the subject phenomenon.

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K. H. Jehn

The objectives of television weather presentations are reviewed and are seen as a particular challenge to both professional meteorologists and television people. An effort is made to analyze the factors involved in the situation and to suggest possible means of realizing the objectives.

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K. H. Jehn
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K. H. Jehn

Abstract

The concept of potential refractive index is examined in the light of earlier work and of the present emphasis on synoptic-scale radio meteorology. A new potential refractive index is defined and illustrated. It is concluded that the new parameter has operational utility in long-range microwave radio and radar transmission as well as in refractive index mapping.

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K. H. Jehn
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K. H. Jehn
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K. H. Jehn
and
J. R. Gerhardt

Abstract

Preliminary time- and height-distributions of the coefficient of eddy conductivity (K H) are presented for three different 24-hour periods for locations in east-central Texas and southern Arizona. It was found that daytime values of K H exceed nighttime values at all levels to 60 meters, and that the coefficient increases more rapidly with height during the day. In general, there appears to be a nearly logarithmic height distribution of K H near midday, and at night a marked tendency for K H to reach a maximum in the layer under consideration.

The methods used in obtaining representative temperature profiles and in computing values of the coefficient are described.

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K. H. Jehn
and
J. R. Gerhardt

Abstract

Determinations of the turbulent flux of heat at the earth's surface are made for the period 24–25 January 1950 at Manor, Texas, with use of mean vertical gradients of air temperature and wind speed, following the Lettau model of non-isotropic turbulence. Simultaneous measurements of net radiation at the surface and of heat interchange in the soil give independent measures of the eddy heat flux, which show reasonable agreement with theory under certain conditions. It is shown that these conditions are apparently such as to require the use of representative values of the potential-temperature difference over a height interval in the surface layer during daylight hours, and of the ratio of mean wind to adiabatic wind at a level in the surface layer at night. It is further observed that the use of the temperature profile in the computation of net heat flux during night hours gives rise to values of negative heat transfer greater in magnitude than theoretical critical limits.

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