Transequatorial loops interconnecting McMath regions 12472 and 12474

We discuss the life-story of a transequatorial loop system which interconnected the newly born active region McMath 12474 with the old region 12472. The loop system was probably born through reconnection accomplished 1.5 to 5 days after the birth of 12474 and the loops were observed in soft X-rays for at least 1.5 days. Transient sharpenings of the interconnection and a striking brightening of the whole loop system for about 6 hr appear to be caused by magnetic field variations in the region 12474. A flare might have been related to the brightening, but only in an indirect way: the same emerging flux could have triggered the flare and at the same time strengthened the magnetic field at the foot-points of the loops. Electron temperature in the loop system, equal to 2.1 × 10⁶ K in its quiet phase, increased to 3.1 × 10⁶ K during the brightening. Electron density in the loop system was 1.3 × 10⁹ cm^–3 and it could be estimated to 7 × 10⁸ cm^–3 prior to the brightening. During the brightening the loops became twisted. There was no obvious effect whatsoever of the activity in 12474 upon the in erconnected old region. The final decay of the loop system reflected the decay of magnetic field in the region 12474.     

Fragmentation model of meteoroid motion,mass loss,and radiation in the atmosphere

Abstract— We present the basic differential equations of meteor physics (the single body equations). We solve them numerically including two possible types of fragmentation: into large pieces and into a cluster of small fragments. We have written a Fortran code that computes the motion, ablation and light intensity of a meteoroid at chosen heights, and allows for the ablation and shape density coefficients σ and K, as well as the luminous efficiency τ, to be variable with height/time. We calibrated our fragmentation model (FM) by the best fit to observational values for the motion, ablation, radiation, fragmentation and the terminal masses (recovered meteorites) for the Lost City bolide. The FM can also handle multiple and overlapping meteor flares. We separately define both the apparent and intrinsic values of σ, K, and τ. We present in this paper values of the intrinsic luminous efficiency as function of velocity, mass, and normalized air density. Detailed results from the successful application of the FM to the Lost City, Innisfree, and Benesov bolides are also presented. Results of applying the FM to 15 bolides with very precise observational data are presented in a survey mode (Table 7). Standard deviations of applying our FM to all these events correspond to the precision of the observed values. Typical values of the intrinsic ablation coefficient are low, mostly in the range from 0.004 to 0.008 s² km^?2, and do not depend on the bolide type. The apparent ablation coefficients reflect the process of fragmentation. The bolide types indicate severity of the fragmentation process. The large differences of the “dynamic” and “photometric” mass from numerous earlier studies are completely explained by our FM. The fragmentation processes cannot be modeled simply by large values of the apparent ablation coefficient and of the apparent luminous efficiency. Moreover, our new FM can also well explain the radiation and full dynamics of very fast meteoroids at heights from 200 km to 130 km.     

Homologous Flares and Magnetic Field Topology in Active Region NOAA 10501 on 20 November 2003

We present and interpret observations of two morphologically homologous flares that occurred in active region (AR) NOAA 10501 on 20 November 2003. Both flares displayed four homologous Hα ribbons and were both accompanied by coronal mass ejections (CMEs). The central flare ribbons were located at the site of an emerging bipole in the centre of the active region. The negative polarity of this bipole fragmented in two main pieces, one rotating around the positive polarity by ≈ 110° within 32 hours. We model the coronal magnetic field and compute its topology, using as boundary condition the magnetogram closest in time to each flare. In particular, we calculate the location of quasi-separatrix layers (QSLs) in order to understand the connectivity between the flare ribbons. Though several polarities were present in AR 10501, the global magnetic field topology corresponds to a quadrupolar magnetic field distribution without magnetic null points. For both flares, the photospheric traces of QSLs are similar and match well the locations of the four Hα ribbons. This globally unchanged topology and the continuous shearing by the rotating bipole are two key factors responsible for the flare homology. However, our analyses also indicate that different magnetic connectivity domains of the quadrupolar configuration become unstable during each flare, so that magnetic reconnection proceeds differently in both events.     

Earthquake distribution and volcanism in Kamchatka,Kurile Islands,and Hokkaido Part 3: Southern Kuriles and Hokkaido

Summary The morphology of the Wadati-Benioff zone in the region of Southern Kuriles and Hokkaido, based on the distribution of 4015 earthquake foci, verified the existence of an intermediate depth aseismic gap and its relation to active andesitic volcanism. A paleosubduction zone activated by an intermediate depth collision with the active subduction zone was found and described.

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u Wadati-Benioff amu uu - u a¶rt;, aa a an¶rt;uu 4015 a mu, nm¶rt;ua mau n¶rt; au u amu a¶rt;um au. a a¶rt;a u nuaa a na¶rt;uu, amuuuaa nmu mu amu ¶rt;uu.

     

An anthropo-ecological approach to landscape use optimization

A method of landscape evaluation based on the anthropo-ecological approach is worked out. The procedure consists of three stages, viz., general, special and optimization. Within the general stage, the structural arrangement of the landscape is evaluated by means of the concept of geo-ecological sites (GES), which are distributed into four zones (A, B, C, D) according to the degrees of their anthropic disturbance. The zoning performed makes it possible to select those geo-ecological sites where eco-critical relationships can be expected to appear; in order to eliminate such situations, transition zones are calculated for the geo-ecological sites concerned. The outcome of this approach is a proposal of a new structural arrangement of the geo-ecological sites, solving eco-critical situations and serving as a basis for the special and optimization stages of the anthropo-ecological method.     

The blast near Eschenlohe,Bavaria, recorded at Průhonice

Резюме Приводятся результаты анализа записей двух камерных взрывов, имевших место 15-го Февраля 1958 г. в Баварии. Взрывы были регистрированы двумя вертикальными электродинамическими сейсмографами, иаготовленными в Геофизическом институте ЧСАН и назначенными для регистравии слабых тектонических толчков.

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Address: Boční II, Praha 13-Spořilov.     

О ВЗАИМОДЕЙСТВИИ МЕЖДУ ВЫСОТНЫМИ АТМОСФЕРНЫМИ ВИХРЯМИ И НАЗЕМНЫМ ТЕЧЕНИЕМ

Summary It is shown that non-divergent vortices may induce, as a result of the resonance effect, a rapid surface development.     

Mercury monitoring: Mercury stability in bird feathers

The influence of ultraviolet light, heating, freezing and weathering on the mercury concentration in the primary feathers from Guillemot and Black Guillemot has been examined. Even within 8 months of exposure variation in mercury concentration due to either loss of mercury or weight loss of the feathers has been found to be less than 10% relative.