Motions and lifetimes of the penumbral bright grains in sunspots

It is confirmed that the penumbral bright grains are moving towards the sunspots umbra. We find different proper motions of 0.08 to 0.33 km s^–1 for different penumbrae and different reduction methods. The lifetimes of these bright grains are about 1.5 to 3 hr depending on the position in the penumbra.     

GHOST – A Novel Airborne Gas Chromatograph for In Situ Measurements of Long-Lived Tracers in the Lower Stratosphere: Method and Applications

A novel fully-automated airborne gas chromatograph for in situmeasurements of long-lived stratospheric tracers hasbeen developed, combining the high selectivity of a megabore PLOTcapillary column with recently developed sampling and separationtechniques. The Gas cHromatograph for theObservation of Stratospheric Tracers (GHOST)has been successfully operated during three STREAM campaigns(Stratosphere TRoposphere Experiment byAirborne Measurement) onboard a Cessna Citation IIaircraft in two different modes: Either N₂O andCF₂Cl₂(CFC-12) or CFC-12 and CFCl₃ (CFC-11) have been measuredsimultaneously, with a time resolution of 2 min for both modes.Under flight conditions the instrument precision (1) forthese species is better than 0.9%, and the accuracy(1) is better than 2.0% of the tropospheric values ofall measured compounds. The detection limits (3) arebelow 28 ppb for N₂O, 14 ppt for CFC-12, and 8 ppt forCFC-11, respectively, i.e., well below 10 % of the troposphericvalues of all measured compounds. Post-mission optimization of thechromatographic separation showed a possible enhancement of thetime resolution by up to a factor of 2, associated with acomparable increase in precision and detection limit. As test ofactual performance of GHOST results from an in-flight N₂Ointercomparison with a tunable diode laser absorptionspectrometer (TDLAS) are presented. They yield an excellentagreement between both instruments. Furthermore, on the basis ofthe hitherto most extensive set of upper tropospheric and lowerstratospheric data, the relative stratospheric N₂2O lifetime isre-assessed. When referenced to the WMO reference CFC-11 lifetimeof 45 ± 7 years an N₂O lifetime of 91 ± 15 yearsis derived, a value substantially smaller than the WMO referencelifetime of 120 years. Moreover, this value implies astratospheric N₂O sink strength of 16.3 ± 2.7 Tg (N)yr^–1 which is 30% larger than previous estimates.     

Theoretical seismogram constraints on some crustal velocity models in the central United States

Summary Earthquake investigations in the central United States require a realistic crustal model for accurate location of seismic events, for the determination of earthquake source parameters, and for theoretical ground motion prediction for an assumed earthquake source. A number of crustal models have been proposed which were based on first arrival refraction data obtained from artificial and natural seismic sources.The reflectivity method for generating realistic theoretical seismograms is used together with recently acquired refraction survey data to distinguish among several of the proposed crustal models. The data used in this study preclude a definitive statement about the nature of the lower crust in the region. However, a crust with two or more layers in the upper 20 km immediately below the basement is preferred. The absence of prominent near yertical reflections suggests that the layers may be separated by rapid velocity gradients rather than by sharp discontinuities.     

Über das Granitmassiv des Symvolon-Gebirges bei Kavala

Zusammenfassung Das Symvolon-Gebirge bei Kavala in Griechisch-Mazedonien wird von einem blastomylonitisch verformten Granitmassiv aufgebaut mit einheitlicher passiver Gefügeregelung. Es sind zwei altersverschiedene Biotite enthalten, nur die primären Biotite zeigen pleochroitische Höfe um Zirkon, die jüngeren, bei der Verformung umkristallisierten Biotite dagegen nicht. Dies spricht für eine bedeutende Differenz zwischen Erstarrung und Deformation. Eine noch jüngere Beanspruchung führt zur Entstehung von Myloniten in Grünschieferfazies. Hervorgehoben wird das Vorkommen junger metasomatischer Aplite, die den gefalteten Bau diskordant durchsetzen.

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The Symvolon-Mts. near Kavala (Greece) consist of a granite-complex with blastomylonite-deformation and a uniform, secondary fabric. The rock contains two biotites of different ages of whom only the older type displays pleochroitic halos around Zircons. This might indicate that, the time interval between solidification and, the deformation might have been considerable. A still more recent deformation produced mylonites in a Greenschist Facies. Late metasomatic Aplites cut the whole complex obliquely.

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Résumé La chaîne du Symvolon près de Kavala dans la Macédoine grecque est constituée par un massif granitique déformé par voie blasto-mylonitique, avec une régulation structurale passive uniforme. Il contient 2 biotites d'âge différent; seules les biotites primaires montrent des auréoles pléochroïques autor du zircon, à l'inverse des biotites plus jeunes qui ont cristallisé au cours de la déformation. Ceci plaide en faveur d'une notable différence entre consolidation et déformation. Une nouvelle déformation engendre des mylonites à faciès de schistes verts. On souligne l'intervention d⁴aplites métasomatiques plus jeunes qui recoupent la structure plissée de façon discordante.

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Über die Selbständigkeit des Minerals Fischerit

Ohne Zusammenfassung     

Outer-zone electron boundary according to intercosmos-13 measurements

Summary The position of the high-latitude boundary for electrons of E_e>40 keV and E_e>1 MeV on a low-altitude satellite is studied. An assymetry of this boundary with respect to magnetic local time has been detected. This assymetry depends on geomagnetic activity. Changes of boundary position are more pronounced for lower energies than for higher. The boundary positions obtained by Intercosmos-13 are compared with those obtained by the OGO-6 and AZUR satellites.