5,793 research outputs found

    Improved reference models for middle atmosphere ozone

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    Improvements are provided for the ozone reference model which is to be incorporated in the COSPAR International Reference Atmosphere (CIRA). The ozone reference model will provide considerable information on the global ozone distribution, including ozone vertical structure as a function of month and latitude from approximately 25 to 90 km, combining data from five recent satellite experiments (Nimbus 7 LIMS, Nimbus 7 SBUV, AE-2 SAGE, Solar Mesosphere Explorer (SME) UVS, and SME IR). The improved models are described and use reprocessed AE-2 SAGE data (sunset) and extend the use of SAGE data from 1981 to the period 1981-1983. Comparisons are shown between the ozone reference model and various nonsatellite measurements at different levels in the middle atmosphere

    Ozone reference models for the middle atmosphere (new CIRA)

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    Models of ozone vertical structure were generated that were based on multiple data sets from satellites. The very good absolute accuracy of the individual data sets allowed the data to be directly combined to generate these models. The data used for generation of these models are from some of the most recent satellite measurements over the period 1978 to 1983. A discussion is provided of validation and error analyses of these data sets. Also, inconsistencies in data sets brought about by temporal variations or other factors are indicated. The models cover the pressure range from from 20 to 0.003 mb (25 to 90 km). The models for pressures less than 0.5 mb represent only the day side and are only provisional since there was limited longitudinal coverage at these levels. The models start near 25 km in accord with previous COSPAR international reference atmosphere (CIRA) models. Models are also provided of ozone mixing ratio as a function of height. The monthly standard deviation and interannual variations relative to zonal means are also provided. In addition to the models of monthly latitudinal variations in vertical structure based on satellite measurements, monthly models of total column ozone and its characteristic variability as a function of latitude based on four years of Nimbus 7 measurements, models of the relationship between vertical structure and total column ozone, and a midlatitude annual mean model are incorporated in this set of ozone reference atmospheres. Various systematic variations are discussed including the annual, semiannual, and quasibiennial oscillations, and diurnal, longitudinal, and response to solar activity variations

    Statistical analysis of direct-strike lightning data (1980 to 1982)

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    Electromagnetic measurements are being made during direct lightning strikes by NASA Langley Center using a specially instrumented F-106B aircraft. The research is to aid refinement, characterization, and understanding of the lightning-aircraft interaction process and the lightning hazards to aircraft. Statistical methods are applied to characterize some aspects of the lightning data obtained from 176 strikes to the aircraft. Specific attention is given to the problem of estimating the upper extreme quantiles of the distributions of peak-to-peak values for currents and rates of change in the magnetic and flux densities. A formal treatment via a general location-scale family of models allows the estimation method to be adapted to the realized shapes the distributions. The shapes are examined by probability plotting methods

    Response of middle atmosphere to short-term ultraviolet variations: 2. Theory

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    Partial purification of human colonic carcinoma cells by sedimentation.

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    We have purified epithelial cells from human colonic tumours by velocity sedimentation in an isokinetic density gradient of Ficoll in tissue culture medium. In frozen sections of colonic carcinoma, histochemically demonstrable N-acetyl-beta-D-glucosaminidase (HDAG) was observed primarily in epithelial cells. We used this enzyme as a histochemical marker of epithelial cells. Initial suspensions of cells from colonic tumours suspended with 0-25% trypsin contained an average of 24% of the nucleated cells with HDAG. In the purest fraction obtained from gradient centrifugations, an average of 74% of the nucleated cells contained HDAG. After centrifugation, the quarter of the density gradient which contained the most rapidly sedimenting cells was purified 2-4-fold over that in the initial suspension. Cells in this zone of the gradient also gave rise to colonies in soft agar. Cells from initial suspension resulted in 15-25% as many colonies of 7 or more cells in cultures inoculated with the same number of nucleated cells. For the most part, cells obtained from the other zones of the gradient did not give rise to colonies in soft agar

    TOKES studies of the thermal quench heat load reduction in mitigated ITER disruptions

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    Disruption mitigation by massive gas injection (MGI) of Ne gas has been simulated using the 3D TOKES code that includes the injectors of the Disruption Mitigation System (DMS) as it will be implemented in ITER. The simulations have been done using a quasi-3D approach, which gives an upper limit for the radiation heat load (notwithstanding possible asymmetries in radial heat flux associated with MHD). The heating of the first wall from the radiation flash has been assessed with respect to injection quantity, the number of injectors, and their location for an H-mode ITER discharge with 280 MJ of thermal energy. Simulations for the maximum quantity of Ne (8 kPa m3) have shown that wall melting can be avoided by using solely the three injectors in the upper ports, whereas shallow melting occurred when the midplane injector had been added. With all four injectors, melting had been avoided for a smaller neon quantity of 250 Pa m3 that provides still a sufficient radiation level for thermal load mitigation

    Storm hazards '79: F-106B operations summary

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    Preliminary flight tests with a F-106B aircraft were made on the periphery of isolated thunder cells using weather radar support. In addition to storm hazards correlation research, a direct-strike lightning measurement experiment and an atmospheric chemistry experiment were conducted. Two flights were made to close proximity to lightning generating cumulonimbus clouds; however, no direct lightning strikes were experienced. Although no discernible lightning transients were recorded, many operational techniques were identified and established

    Genome Sequencing of a Marine Spirillum, Oceanospirillum multiglobuliferum ATCC 33336T, from Japan

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    Oceanospirillum multiglobuliferum ATCC 33336T is a motile gammaproteobacterium with bipolar tufted flagella, noted for its low salt tolerance compared to other marine spirilla. This strain was originally isolated from the putrid infusions of Crassostrea gigas near Hiroshima, Japan. This paper presents a draft genome sequence for O. multiglobuliferum ATCC 33336T
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