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H. STUART MUENCH

Abstract

When comparing rocketsonde and balloonsonde (radiosonde) temperature data, one notes systematic differences at levels of 25 km and above that increase with height. During the past 10 yr, systematic errors in the rocketsonde have been largely eliminated (at least for the region from 20 to 45 km), but little attention has been paid to the balloonsonde sensor. A study of temperature data for June 1967 suggests about half the difference is due to infrared cooling of the balloonsonde thermistor and much of the remaining difference may be due to the thermistor riding up through the wake of a balloon cooled by radiative and adiabatic processes. These errors make balloonsonde temperature data above 30 km unsuitable for many types of study.

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H. Stuart Muench

Abstract

Experience with a surface prognostic technique developed by Reed revealed some systematic defects, which were corrected subjectively in practice. In hopes of eliminating the defects, a forecast equation is derived here in a manner slightly different than the derivation of Reed, but which may still be used in a simple forecast scheme. This new equation is applied to a three-day period during January 1964, with fairly successful results. However, an ageostrophic correction, computed from thickness advection patterns, had to be applied to obtain a reasonable position forecast for a cold front in advance of a strong polar outbreak.

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H. Stuart Muench

Forecasting severe weather conditions is a difficult problem due to both the small size and short lifetime of the storms. Conventional weather information is too coarse in time and space to follow individual storms but can indicate areas where probability of occurrence is many times higher than climatological values. Weather radars have the resolution in time and space to track severe storms, but present operational radars are not equipped to give quantitative data. Recent developments in electronics and data processing have greatly simplified the task of obtaining quantitative data, and examples are shown of work underway at Air Force Geophysics Laboratory in using digital radar to forecast small-scale convective storms. Experiments have been made in automatically tracking storms and producing guidance forecasts of severe weather probability. A difficult problem remains in developing relationships between radar measurements and intense wind, rain, and hail due to the scarcity of meteorological measurements of such unusual events.

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H. Stuart Muench

Abstract

The dynamics of the large-scale circulation pattern of the stratosphere in mid-winter is examined. A set of energy equations is derived which is applicable to the stratosphere as an open system. The terms of these equations, interpreted as energy conversions and fluxes, are evaluated using data from January 1958. The computed energy conversions were similar in sign to those found in the troposphere, and varied only in magnitude during the month, reaching maximum values prior to and during the stratosphere warming. The energy flux terms indicate a considerable amount of energy was transferred into the stratosphere through a correlation of the vertical velocity and geopotential, at the expense of energy of the troposphere. The possibility of a stratosphere-troposphere coupling is investigated further through harmonic analyses of the height field at levels from 1000 mb to 10 mb at 50N. A vertical consistency of the long waves is revealed, throughout the depth studied, and evidence is found for the existence of periodic amplifications of wave numbers one and two which propagate upwards at the rate of about 6 km per day. From observational evidence a model is deduced to explain many of the observed features of the stratosphere circulation.

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H. Stuart Muench

Abstract

High-level balloon data from the region of western Europe through North America to eastern Asia were used to investigate disturbances in the summertime stratosphere from 27–36 km. Systematic diurnal variations were found, with amplitudes up to 2 m sec−1, but the patterns were more complex than would be expected from simple tidal theory. Traveling planetary waves were also found at these altitudes, propagating westward at 30° of longitude per day. The waves were detected as periodic oscillations in the u component, with amplitudes up to 4 m sec−1, extending from 25–45N, and from 25–45 km in the vertical. A solution to the barotropic vorticity equation was found which possesses many of the observed features when applied to 10 mb (31 km) data. While it is suspected that both the diurnal wind patterns and the traveling waves are forced by tropospheric disturbances, the causes of neither could be determined.

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George Ohring and H. Stuart Muench

Abstract

Relationships between atmospheric ozone and meteorological parameters in the lower stratosphere over Europe are studied. Correlation coefficients between total ozone amount and temperature, geopotential height, and north-south wind component at 100 mb are presented. The distribution of ozone amounts in relation to stratospheric troughs and ridges is shown.

High ozone amounts are found to be associated with high temperatures, low geopotential heights, southerly winds, and cyclonic-contour curvatures in the lower stratosphere. The results are discussed qualitatively in terms of stratospheric motions and the distribution of ozone.

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Keith L. Seitter and H. Stuart Muench

Abstract

Observations are presented of a cold front which passed over the Florida peninsula and produced a rope cloud visible on satellite imagery. The low level structure of the leading edge of the front is revealed with data from the 150 m tower at Cape Canaveral Air Force Station. It is shown that the leading edge of the front is very similar to thunderstorm gust fronts and the speed is predicted well by the gust front speed equation. This indicates that the rope cloud is directly analogous to the arc cloud sometimes observed along thunderstorm gust fronts. Further, the rope cloud appears to be a less intense manifestation of the forced convection that produces the narrow cold‐frontal rainbands observed in some other cold front studies.

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