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FRANCIS J. SCHMIDLIN

Abstract

A graphical method of determining pressure from rocketsonde temperature-measurements is presented, and information for the construction and use of such a graph is given. This graphical method is shown to be simple and rapid. Comparison with results from computer processing of the same temperature data yields pressure differences of only 0.5 percent in 72 percent of the cases, and 1 percent in 90 percent of the cases.

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FRANCIS J. SCHMIDLIN

Abstract

An investigation to determine whether rocketsonde temperatures are significantly different from radiosonde temperatures was made using published data for Wallops Island, Va. Statistical comparison between the Arcasonde 1A and ESSA's hypsometer-equipped “outrigger thermistor” type radiosonde revealed their measurements to be significantly different. Examination of the mean temperatures yielded by each measuring system for the winter and summer seasonal data revealed a constant difference below 26 km, while above this altitude the difference increased with altitude. The range of winter–summer mean temperatures computed from each system also showed good agreement except above 26 km where the range increased at a different rate. It is believed these differences in the temperature profiles may be caused by radiation influences acting differently on each sensor. The need for further investigation of these differences is indicated.

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Alvin J. Miller and Francis J. Schmidlin

Abstract

In an attempt to separate instrument system “noise” from actual stratospheric variability, six pairs of meteorological rocketsondes (Datasonde instruments) were launched on 20 June 1969, with five pairs being released at 1-hr intervals; the two individual rockets comprising a pair were separated by time intervals of no more than 5 min. The average rms difference between paired soundings was 1.08C and ∼3 m sec−1. These rather low rms values contrasted sharply with rather large changes observed in both the temperature and wind fields. Further research is needed into the interpretation of this variability in terms of mesoscale and small-scale phenomena.

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Frederick G. Finger and Francis J. Schmidlin

The tremendous interest in upper-air measurement quality by the meteorological community brought together experts from many agencies at a Workshop on Upper-Air Measurements and Instruments. The workshop was held at NASA's Wallops Island facility on 14–15 November 1989. The purpose of the workshop was to establish a forum for the interchange of information to discuss mutual problems and to provide a basis for future work. A major recommendation of the workshop was for the development of a reference radiosonde instrument. A description of the workshop highlights are presented.

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Anne M. Thompson, Jacquelyn C. Witte, Samuel J. Oltmans, and Francis J. Schmidlin

This article describes the Southern Hemisphere Additional Ozonesondes (SHADOZ) network of ozonesonde-radiosonde stations in the southern Tropics and subtropics. SHADOZ was initiated in 1998 by NASA, NOAA, and a team of international meteorological services and space agencies to remedy a paucity of ozone profile data in a region of intense natural variability and anthropogenic change. SHADOZ augments launches at selected sites and provides a public archive of ozonesonde and radiosonde data (see additional information online at http://croc.gsfc.nasa.gov/shadoz). Ozone is important because of its role as an atmospheric UV shield, surface pollutant, oxidant, and greenhouse gas. Ozone profile data are essential for the detection of ozone trends and for verification of satellite ozone retrievals. Instrumentation, data, and a summary of the first scientific findings from SHADOZ are presented. A zonal view shows that troposphere ozone accumulates over the south tropical Atlantic and adjacent continents throughout the year, consistent with large-scale atmospheric motion. At individual stations, week-to-week variations in tropospheric ozone profiles reflect episodic meteorology, for example, convection or advected pollution.

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Frederick G. Finger, Melvyn E. Gelman, Francis J. Schmidlin, Robert Leviton, and Bruce W. Kennedy

Abstract

Under the auspices of the Commission for Instruments and Methods of Observation of the World Meteorological Organization, meteorological rocketsonde intercomparisons took place at Wallops Island in March 1972 and at the Guiana Space Center, French Guiana, in September 1973. France, Japan and the United States participated in the Wallops tests, and France, the United Kingdom, the Union of Soviet Socialist Republics and the United States participated in the Guiana tests. Measurements were made during the day as well as at night.

Comparisons ire presented of temperature and wind data obtained by the different rocketsonde systems over the. altitude region from 25 to 80 km. Results indicate generally good compatibility among temperatures obtained below approximately 50 km. Above that level, biases increasing with height are evident. Temperature adjustments are derived, which, when applied to operational rocketsonde data, would in the mean achieve compatibility for synoptic analyses and other uses. Comparisons among wind observations indicate generally good agreement below approximately 60 km. However, some significant problem areas are pointed out and discussed.

The Guiana series of observations also provided valuable information on the diurnal temperature change at stratospheric and mesospheric levels. An evaluation of this aspect is presented, and results are compared with those predicted by tidal theory.

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