Balloon Soundings Research Articles

Local winds in the upper Rhone Valley

Balloon soundings during July and August 1979, 1981 and 1982 showed the vertical structure of the flow in the upper Rhone Valley. Between the low level winds up to a height of about 2000 m a s l and the gradient winds above 3000 m a s l, in 73 % of the 107 ascents, a counterflow was detected. It appeared more often in connection with down-valley flow (89 %) than with up-valley flow (38 %) above the ground. This flow pattern was found to be almost unaffected by the upper winds.

The ozonesonde intercomparison experiment at Thumba

An Indo-Soviet collaborative experiment on Ozonesonde Intercomparison was conducted at TERLS in March 1983. Thirteen rocket ozonesondes, eleven balloon ozonesondes and seven meteorological rockets were launched from Thumba. The rocket and balloon soundings were supported by on site Dobson spectrophotometric observations, surface ozone measurements as well as measurements with a Volz type filter photometer. The programme has yielded data on ozone vertical profiles from eleven rocketsondes, seven balloon-sondes and four sets of Umkehr observations. The data is studied with a view to intercompare the various sensors.

Star line‐of‐sight refraction observations from the Orbiting Astronomical Observatory Copernicus and deduction of stratospheric structure in the tropical region

Night‐time observations from the orbiting astronomical observatory Copernicus on May 14 and July 11, 1980, of visible light refraction by the limb of the atmosphere are presented. Irregularities of the measured refraction angle are then interpreted to be probably the result of the thermal fine structure in the stratosphere. The observations are very sensitive to horizontally stratified structures with temperature deviations of 2 to 5°K, if the vertical dimension is less than 3 km. Since under selected geometric conditions the star's line of sight to the orbiting satellite sweeps out hundreds of kilometers at almost constant altitude, the observations are used to estimate the horizontal dimensions of thermal structures; Particularly large structures were found in the ozone region of the stratosphere. The refraction measurements are in general agreement with balloon soundings, UHF vertical soundings, and infrared radiometer observations of the limb.

The pulse profile of the Crab pulsar in the energy range 45 keV-1.2 MeV

view Abstract Citations (17) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The pulse profile of the Crab pulsar in the energy range 45 keV-1.2 MeV. Wilson, R. B. ; Fishman, G. J. Abstract The Crab Nebula pulsar (PSR 0531+21) is the best studied and most intense of the nontransient X-ray pulsars. However, since its spectrum drops rapidly with energy, a well-resolved pulse profile has not previously been obtained above 200 keV. In the hard X-ray and low-energy gamma-ray region, an accurate pulse profile can be obtained with a balloon-borne detector of sufficient area during a single transit of the source. A new measurement of the pulse profile of PSR 0531+21 in the energy range above 45 keV obtained with a large-area scintillation detector array is reported. The detector array was flown on a balloon launched from Palestine, Texas on 1980 October 6, reaching a float altitude 4.5 g/sq cm at 0230 UTC October 7. The primary objective of the experiment was to detect and study weak gamma-ray bursts. Publication: The Astrophysical Journal Pub Date: June 1983 DOI: 10.1086/161039 Bibcode: 1983ApJ...269..273W Keywords: Crab Nebula; Energy Spectra; Gamma Rays; Pulsars; X Ray Sources; Balloon Sounding; Data Reduction; High Energy Interactions; Profiles; Radiation Detectors; Astrophysics full text sources ADS | data products SIMBAD (2)

Ultralight Sounder: An Airborne System for Studying the Planetary Boundary Layer

Abstract Until recently, investigations of the temperature structure of the planetary boundary layer have been confined to the use of balloon soundings (tethered balloon sondes, rawinsondes), disposable drop-sondes, or high performance instrumented aircraft. These methods can be quite restrictive in their ability to obtain detailed temporal and spatial resolutions, especially in areas of limited accessibility. The operating cost of an instrumented aircraft also may be prohibitive. From this perspective, the use of an ultralight sounder—a meteorological sensor mounted on a motorized glider—is described, and its versatility is discussed. This system was employed in measuring the vertical temperature structure in mountainous terrain during the winter months of 1981–82. The system's capability to obtain detailed vertical temperature structure, as attested by the data gathered, renders it invaluable in the study of the planetary boundary layer in complex mountainous terrain.

Mesoscale observations of upstream blocking

AbstractAnalysis of detailed tethered balloon soundings simultaneously undertaken at two sites in a valley shows that blocked (i.e. near stagnant) flow upwind of the ridges is characterized by a critical internal Froude number, Fr = uaH−1(gγa/θr)−1/2 of approximately 1.6. For Fr above this value the air in the valley is swept out by ambient wind. Otherwise blocking to near ridge height is observed. Here ua is ambient wind speed measured above ridge height H, g is acceleration due to gravity, θr a reference potential virtual temperature and γa the ambient vertical gradient of this quantity.

The lower atmosphere of the polar regions

Alfred Wegener initiated the study of the free polar atmosphere with more than 100 kite and tether balloon soundings to above 3000 m at Danmarkshavn, North Greenland, during 1906–09. From this beginning polar aerology advanced through a series of similar point studies to the first full upper air network during the IGY (1957/8). While its replacement by satellite remote sensing is gradually taking shape, the accumulated polar information has been thoroughly analyzed; a series of comprehensive accounts is referenced. The aspects singled out for this review are themes that would have been of special interest to Wegener — the surface energy balance and the polar inversion, the katabatic winds and snow drift, and the aerosols of the polar atmosphere.

The Application of Airborne Radar Altimetry to the Measurement of Height and Slope of Isobaric Surfaces

The aeronautical use of electronic altimeters is to measure the absolute clearance of an aircraft above the earth's surface. In the support of atmospheric research, accurate high-range altimeters, in conjunction with accurate static pressure and navigation data, also can provide a means for measuring the heights of constant-pressure surfaces. From the derivatives of the measurements, surface slopes and dynamical quantities such as the geostrophic wind may be obtained. Although the technique is easiest over oceans or large bodies of water, it can be successfully used over land, if detailed terrain heights are known. This paper describes the operational and research use of a high-altitude pulse-type radar altimeter system installed on the NCAR Sabreliner for jet stream research. An error analysis for “D-value”, derived from radar altitude and pressure measurements, gave an estimated error of ±6.0 m, which surpasses measurements from conventional balloon soundings or satellite-derived height analyses. For a case study of jet stream dynamics, the above error in D-value corresponded to an error of ±5% in the computed geostrophic wind.

An Observation System Used To Study the Marine Boundary Layer Over the Bay of Bengal During Summer Monex 79

An observation system used to study the marine boundary layer over the Bay of Bengal at Digha Beach, West Bengal, India, as part of the International Monsoon Experiments (MONEX 79) is described in this paper. It was a portable system that was designed to facilitate ease in transportation, to be quick to assemble, independent and self-sufficient in power supply, and to operate in remote sites for long periods of time. The experiments consisted of measurements of atmospheric turbulence and fluxes of momentum, heat, and water vapor from a 10 m high coastal meteorological tower. Mean meteorological parameters were measured with an automated electronic weather station. Wind speed and direction profiles in the planetary boundary layer were obtained with pilot balloon soundings.

The vertical component of 1-20 MeV gamma rays at balloon altitudes

view Abstract Citations (72) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The vertical component of 1-20 MeV gamma rays at balloon altitudes Schoenfelder, V. ; Graml, F. ; Penningsfeld, F. -P. Abstract The diffuse cosmic and the vertical atmospheric component of 1-20 MeV gamma rays are determined from the gamma-ray data obtained during a balloon flight of the large-area Compton telescope of the Max-Planck-Institut. It is shown that the basic improvement of this new measurement above previous measurements with a first version of the Compton telescope is based on the fact that for each registered event various additional parameters are determined. Further, by means of the pulse shape measurement of neutron-induced events it is possible to determine most of the undesired background events from the data themselves. Finally, consideration is given to the origin of the diffuse cosmic gamma-ray component, and the results of the atmospheric gamma-ray component are compared with different model calculations. Publication: The Astrophysical Journal Pub Date: August 1980 DOI: 10.1086/158239 Bibcode: 1980ApJ...240..350S Keywords: Balloon Sounding; Cosmic Rays; Gamma Rays; Vertical Distribution; Atmospheric Radiation; Background Radiation; Compton Effect; Diffuse Radiation; Energy Spectra; Extraterrestrial Radiation; Space Radiation full text sources ADS |

Energy spectra of cosmic-ray nuclei to above 100 GeV per nucleon

view Abstract Citations (112) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Energy spectra of cosmic-ray nuclei to above 100 GeV per nucleon Simon, M. ; Spiegelhauer, H. ; Schmidt, W. K. H. ; Siohan, F. ; Ormes, J. F. ; Balasubrahmanyan, V. K. ; Arens, J. F. Abstract Energy spectra of cosmic-ray nuclei boron to iron have been measured from 2 GeV per nucleon to beyond 100 GeV per nucleon. The data were obtained using an ionization calorimeter flown on a balloon from Palestine, Texas. The 3450 kg payload floated at 7 g/sq cm for almost 24 hours. The results are in excellent agreement with those of other workers where overlaps exist. The spectra are not consistent with single power laws, and demonstrate the power of using a single technique sensitive over a large dynamic range. The data are consistent with the leaky box model of cosmic-ray propagation. The boron data indicate that the cosmic-ray escape length decreases with increasing energy as E to the -(0.4 + or - 0.1) up to 100 GeV per nucleon. Secondary nuclei from iron are also consistent with this dependence. Predicted changes in the energy dependence of the ratios of primary nuclei O/C and (Fe + Ni)/(C + O) are also observed. Publication: The Astrophysical Journal Pub Date: July 1980 DOI: 10.1086/158157 Bibcode: 1980ApJ...239..712S Keywords: Cosmic Rays; Energy Spectra; Nuclei (Nuclear Physics); Backscattering; Balloon Sounding; Balloon-Borne Instruments; Cerenkov Counters; Energy Distribution; Monte Carlo Method; Space Radiation full text sources ADS |

Hard X-ray emission from NGC 4151 and MCG 8-11-11 regions

view Abstract Citations (13) References (6) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hard X-ray emission from NGC 4151 and MCG 8-11-11 regions. Frontera, F. ; Fuligni, F. ; Morelli, E. ; Ventura, G. Abstract Results of the analysis of hard X-ray data obtained during a 1976 transatlantic balloon flight are reported. NGC 4151 was clearly detected with a power-law photon spectrum dN/dE proportional to E to the -(1.2 plus or minus 0.3) power. A new source was also detected in the vicinity of MCG 8-11-11. Association of this object with this Seyfert galaxy is suggested. The contribution of Seyfert galaxies to diffuse background in the hard X-ray range is discussed. Publication: The Astrophysical Journal Pub Date: December 1979 DOI: 10.1086/157517 Bibcode: 1979ApJ...234..477F Keywords: Balloon Sounding; Energy Spectra; Seyfert Galaxies; X Ray Sources; Background Radiation; Balloon Flight; Bremsstrahlung; Diffuse Radiation; Emission Spectra; Space Radiation; Seyfert Galaxies:X-Ray Sources full text sources ADS | data products NED (2) SIMBAD (1)

On the Observed Diurnal Oscillation of the Somali Jet

Abstract The time mean and diurnal oscillation of the Somali jet are examined, using as a data base a high-resolution time series of pilot balloon soundings for two sites in northeast Africa. The diurnal mode is found to contain a significant amount of the total amplitude of the jet. In association with this oscillation, the level of maximum wind varies considerably during the course of a day. A multi-cored jet structure is observed during the afternoon. Other interesting structural variations of the jet are discussed. Hypotheses are ventured to provide explanations for the observed behavior of this low-level jet.

A catalog of X-ray sources

view Abstract Citations (27) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A catalog of X-ray sources. Amnuel, P. R. ; Guseinov, O. Kh. ; Rakhamimov, Sh. Iu. Abstract A catalog of X-ray sources containing 517 objects known as of 1978 February has been compiled. X-ray data collected by means of rockets, balloons, and satellites during 1964-1977 are listed. Optical and radio counterparts are suggested. The existence of the weak X-ray source population in the Galaxy is indicated. Average parameters of the different types of X-ray sources are estimated, as well as the number of X-ray sources of each type in the Galaxy. Publication: The Astrophysical Journal Supplement Series Pub Date: October 1979 DOI: 10.1086/190621 Bibcode: 1979ApJS...41..327A Keywords: Astronomical Catalogs; Galactic Radiation; Spaceborne Astronomy; X Ray Sources; Balloon Sounding; Data Acquisition; Light Emission; Rocket Sounding; Satellite Observation; Tables (Data); X Ray Astronomy; Astronomy; Catalogues:X-Ray Sources; Galaxy:X-Ray Sources; X-Ray Sources:Optical Counterparts; X-Ray Sources:Radio Counterparts full text sources ADS | data products SIMBAD (467) NED (53)

Formation and Characteristics of Coastal Internal Boundary Layers During Onshore Flows

The development and characteristics of coastal internal boundary layers were investigated in 28 tests. These were made at all seasons and in both gradient and sea-breeze flows but only during mid-day periods. Measurements of turbulence and temperature were taken from a light aircraft which flew traverses across Long Island at successive altitudes parallel to the wind direction. These were used to locate the boundary between modified and unmodified air as a function of height and distance from the coast. The same measurements plus tower measurements of wind, turbulence and temperature, pilot balloon soundings and measurements of land and water surface temperatures by a remote sensing IR thermometer were used to quantify the characteristics of the modified and unmodified air.

The mean mass of the abundant cosmic-ray nuclei from boron to silicon at 1.2 GeV per atomic mass unit

view Abstract Citations (38) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The mean mass of the abundant cosmic-ray nuclei from boron to silicon at 1.2 GeV per atomic mass unit. Dwyer, R. Abstract Results are presented for an investigation of cosmic-ray isotopic composition in which a balloon-borne instrument was used to perform an isotopic analysis of the abundant elements from B through Si in the energy range from 1.0 to 1.6 GeV/amu. The technique employed, which depends on the effect of earth's magnetic field on incoming cosmic rays, and reduction of the observational data are described in detail. Mean masses of the elements B, C, N, O, Ne, Mg, and Si are extracted from normalized Cerenkov spectra and evaluated in terms of the 'leaky box' model of galactic propagation and confinement. The implications of the results for cosmic-ray sources are shown to be consistent with the nucleosynthesis of certain isotopes in the cosmic rays in explosive carbon burning under the conditions of peak temperature, density, and neutronization expected in an explosion of a massive highly evolved star. The possibility of alternate interpretations is noted. Publication: The Astrophysical Journal Pub Date: September 1978 DOI: 10.1086/156417 Bibcode: 1978ApJ...224..691D Keywords: Abundance; Cosmic Rays; Heavy Nuclei; Isotope Effect; Nuclear Fusion; Balloon Sounding; Boron; Carbon; Cerenkov Radiation; Energy Methods; Nitrogen; Oxygen; Space Radiation; Cosmic Rays:Isotopic Abundances; Cosmic Rays: Nuclei full text sources ADS |

The Superpressue Balloon Sounding Technique for the Study of Atmospheric Meso-and Microscale Phenomena

Abstract The history of the superpressure balloon sounding technique for scientific investigation of the dynamics of the atmosphere is noted. The technology of the balloon and associated pay-load is briefly described, and the spurious natural oscillations of a balloon about its nominal flight level are discussed. A few sensors specially designed to fly on superpressure balloons are presented, and the difficulties to be overcome in the design are stressed. A few experiments carried out aboard such balloons to study the dynamics of meso- and microscale phenomena in the atmosphere are described, and they show the many possibilities offered by such a technique. The application of this technique to such studies is especially emphasized. In particular, it is shown that different phenomena occurring in the atmosphere from the boundary layer to the middle layers of the stratosphere can be handled at a low cost and specific information can be obtained using satellite relay for data transmission.

The Uppsala urban meteorology project

An extensive urban meteorology project in Uppsala, Sweden, is described. The city itself is considered suitable as a kind of model city, being almost circular, having sharp urban/rural boundaries and being situated in a relatively flat area. The project incorporates numerous measurements. A main station with a 100-m mast is situated at the NE urban/rural border. Its instrumentation consists of a slow-response (‘profile’) system and a turbulence system. The profile instrumentation is described in detail. In addition to the main station, the project comprises: measurements from two 14-m masts, one on the top of a centrally located building, the other mobile; pilot balloon ascents; tethered balloon soundings, car-borne temperature traverses etc. Some preliminary results are presented: analyses of wind profiles from the mast and three-dimensional heat island studies.

A parameterization of heat convection for a numerical sea breeze model

AbstractA hydrostatic model of a sea breeze circulation is developed through numerical integration of the primitive equations. Air flow is assumed inviscid and external gravity waves are filtered by using a rigid‐top boundary condition. Heat is fed directly into the model, and a parameterization of its distribution is developed which does not use diffusion coefficients explicitly. The model is stable for an integration timestep of up to 14 minutes. Computations are carried out for the latitude of Rome. The Apennines are parameterized as a vertical rigid wall, parallel to the shore.The results show good agreement with wind profiles given by pilot balloon soundings at Rome Airport in conditions of a sea breeze circulation. A comparison is made with the two‐dimensional model of Neumann and Marher.

A parameterization of heat convection for a numerical sea breeze model

A hydrostatic model of a sea breeze circulation is developed through numerical integration of the primitive equations. Air flow is assumed inviscid and external gravity waves are filtered by using a rigid-top boundary condition. Heat is fed directly into the model, and a parameterization of its distribution is developed which does not use diffusion coefficients explicitly. The model is stable for an integration timestep of up to 14 minutes. Computations are carried out for the latitude of Rome. The Apennines are parameterized as a vertical rigid wall, parallel to the shore. The results show good agreement with wind profiles given by pilot balloon soundings at Rome Airport in conditions of a sea breeze circulation. A comparison is made with the two-dimensional model of Neumann and Marher.