Comparison of Some Balloon Techniques

MacCready, Paul B.

doi:10.1175/1520-0450(1965)004<0504:cosbt>2.0.co;2

Cited by 20 publications

(16 citation statements)

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“…The drag coefficient of spheres (C dr ) depends on the Reynolds number (Re), which experiences a transition from supercritical value (;2-3 3 10 5 ) in the boundary layer or turbulent layer to subcritical value (;0.5-2 3 10 5 ) in the free troposphere (Vennard 1955;MacCready 1965). Consequently, C dr can change from ;0.2 for supercritical conditions to ;0.5 for subcritical conditions (Vennard 1955).…”

Section: A Methodsmentioning

confidence: 99%

“…Each of these instruments and techniques has its own strengths and limitations, and they all are expensive. The dropsonde fall rate is much smoother than the radiosonde ascent rate because of the radiosonde's pendulum effect and self-induced balloon motion (MacCready 1965). The intent of this paper is to explore the potential to estimate the VV from the surface to the stratosphere using radiosonde and dropsonde data under all weather conditions.…”

Section: Introductionmentioning

confidence: 99%

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Vertical Air Motion from T-REX Radiosonde and Dropsonde Data

Wang

Bian

Brown

et al. 2009

Journal of Atmospheric and Oceanic Technology

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The primary goal of this study is to explore the potential for estimating the vertical velocity (VV) of air from the surface to the stratosphere, using widely available radiosonde and dropsonde data. The rise and fall rates of radiosondes and dropsondes, respectively, are a combination of the VV of the atmosphere and stillair rise-fall rates. The still-air rise-fall rates are calculated using basic fluid dynamics and characteristics of radiosonde and dropsonde systems. This study validates the technique to derive the VV from radiosonde and dropsonde data and demonstrates its value. This technique can be easily implemented by other users for various scientific applications.The technique has been applied to the Terrain-induced Rotor Experiment (T-REX) dropsonde and radiosonde data. Comparisons among radiosonde, dropsonde, aircraft, and profiling radar vertical velocities show that the sonde-estimated VV is able to capture and describe events with strong vertical motions (larger than ;1 m s 21 ) observed during T-REX. The VV below ;5 km above ground, however, is overestimated by the radiosonde data. The analysis of derived VVs shows interesting features of gravity waves, rotors, and turbulence. Periodic variations of vertical velocity in the stratosphere, as indicated by the radiosonde data, correspond to the horizontal wavelength of gravity waves with an averaged horizontal wavelength of ;15 km. Two-dimensional VV structure is described in detail by successive dropsonde deployment.

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Section: A Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Vertical Air Motion from T-REX Radiosonde and Dropsonde Data

Wang

Bian

Brown

et al. 2009

Journal of Atmospheric and Oceanic Technology

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“…This problem has been addressed in MacCready (1965), who showed that these motions are strongly dependent on the Reynolds number Re, where These self-induced motions constitute an undesirable effect that needs to be minimized as much as possible.…”

Section: F Problems Associated With Balloon Aerodynamicsmentioning

confidence: 99%

“…In a comparison between different balloon characteristics, MacCready (1965) demonstrated that the smooth, expandable, neoprene balloons employed in typical radiosonde launches have subcritical Re values (i.e., greatly reduced self-induced motions) over the entire height range, provided that the nominal balloon diameter is #;90 cm. In a comparison between different balloon characteristics, MacCready (1965) demonstrated that the smooth, expandable, neoprene balloons employed in typical radiosonde launches have subcritical Re values (i.e., greatly reduced self-induced motions) over the entire height range, provided that the nominal balloon diameter is #;90 cm.…”

Section: F Problems Associated With Balloon Aerodynamicsmentioning

confidence: 99%

On the Use of Slow Ascent Meter-Scale Sampling (SAMS) Radiosondes for Observing Overturning Events in the Free Atmosphere

Balsley

Kantha

Colgan

2010

Journal of Atmospheric and Oceanic Technology

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This note describes the development of a method for obtaining high vertical resolution (meter scale) measurements of basic meteorological quantities and turbulent overturns, using radiosondes with slow ascent rates. Although the method has some limitations, it can provide profiles of standard atmospheric variables from the surface to more than 20 km, with significantly improved vertical resolution. It can also help better identify regions of turbulent overturns. This correspondence presents some initial results demonstrating the occurrence of relatively small-vertical-scale overturns throughout the entire atmospheric column.

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“…The time constant of the temperature sensor is approximately 2 s, so that the time required for each measurement is largely dependent on that needed to determine the balloon position. Although some of the motion of the balloon in the wind field at each level is self-induced (e.g., Scoggins, 1964Scoggins, , 1965MacCready, 1965;Murrow and Henry, 1965;Rider and Armendariz, 1968), averaging of the balloon position over approximately lo-20 s has provided satisfactory estimates of the mean location and the mean wind velocity at each level. Using this operational procedure, a sounding to 300 m and return typically takes 30 min or less.…”

Section: The System In Operationmentioning

confidence: 99%

A new tethersonde system for remote measurement of wind and temperature

Tapp

Lile

1978

Boundary-Layer Meteorol

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An economical tethersonde system has been developed for use in the light-to-moderate wind conditions typically accompanying nocturnal inversions, to obtain vertical profiles of wind velocity and temperature to heights in excess of 300 m. Minimal capita1 investment and operational expenditure were achieved with the utilization of a spherical balloon, the development of a simple and reliable thermistor temperature sensor, and the development of algorithms to obtain quantitative estimates of wind velocity from the measured position of the balloon and from the known aerodynamic drag properties of both the balloon and the tether. With the length and suspension geometry of the tether line known, an approximation is applied to allow for its non-linearity, and the position vector of the balloon and instrument package can then be determined by a single theodolite fix. The vertical component of the position vector so determined corresponds to the geometric height of the sensor, while the horizontal component is directly related to wind velocity. Heights and horizontal wind velocities estimated by these methods compare well with direct independent measurements.

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Comparison of Some Balloon Techniques

Cited by 20 publications

References 0 publications

Vertical Air Motion from T-REX Radiosonde and Dropsonde Data

Vertical Air Motion from T-REX Radiosonde and Dropsonde Data

On the Use of Slow Ascent Meter-Scale Sampling (SAMS) Radiosondes for Observing Overturning Events in the Free Atmosphere

A new tethersonde system for remote measurement of wind and temperature

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