A vertical interpolation experiment

Summary Vertical interpolation of the data from the constant-pressure to the constant-density surfaces is discussed, and the results of an experiment given, wherein the data are interpolated to a constant-density surface using two different sets of the constant-pressure data. Comparison of the two results gives an estimate of the order of magnitude of the errors inherent in the interpolation.Hydrometeorological Institute of SR Serbia, Belgrade, Yugoslavia. The experiment reported here has been made while the author was visiting the National Center for Atmospheric Research, Boulder, Colorado.     

On the impact on forecast accuracy of the step-mountain (eta) vs. sigma coordinate

Summary Impact on forecast accuracy of the choice of the step-mountain (eta) vs. the traditional sigma coordinate is examined by using a model which can be run as either an eta or sigma system model via a simple switch in its code. This is done by (a) synoptic examination of the differences in a set of three forecasts, and (b) comparison of precipitation skill scores in a set of nine consecutive forecasts; each of these sets of forecasts was performed using one and then the other of the two systems. Both efforts indicate that greater accuracy is achnieved in the step-mountain coordinate forecasts. The three forecasts examined from the synoptic point of view are also compared against forecasts of another sigma system model. The two sigma models are found to have errors of an almost identical pattern (two cases) or to have errors which seemed to have the same basic cause.With 13 Figures     

Shoreline Dynamics of the Islands of the Northern Part of Ushakov Island

Doklady Earth Sciences - The analysis of a large amount of data–satellite images, UAV surveys, meteorological observations of polar stations, and archival data made it possible to establish...     

Chrome spinels and accessory mineralization in the weathering crust of the Vladimir deposit,Varshavsky ultramafic massif,southern Urals

The paper presents the characteristics of chrome spinels from an ore-bearing packet of the Vladimir chromite deposit. Three main types of chrome spinels are distinguished by morphology and chemical composition: medium-chrome ore-forming, high-chrome transformed, and low-chrome relict accessory. The significant role of weathering conditions is expressed in alteration of accessory chrome spinel. The formation of high-chrome spinels is explained by the hydrothermal effect of the Varshavsky granitoid massif with accompanying dikes and talc–carbonate metasomatic rocks. Characteristic accessory minerals are represented by native gold and nickel, millerite, pentlandite, chalcopyrite, maucherite, PGE sulfides, and picroilmenite.     

A dynamical study of the multiple system 17 Cygni ABFG

Adynamical study of the relative motions of the components of the inner pairs AB (ADS 12913) and FG (ADS 12889) of the quadruple heirarchical system 17 Cygni (WDS 19464+3344) is presented, as well as analysis of themotions of the outer pair AB–FG. The study is based on CCD observations obtained on the 26-inch refractor of the Pulkovo Observatory (2003–2013), position observations from the WDS catalog, Hipparcos parallaxes, and radial velocities of the components from literature data. A family of orbits for 17 Cyg AB is obtained for the first time, and has a most probable period of 6200 yrs. The apparent motion parameters (AMP) method is used, since the entire visible arc of the orbit over 1832–2013 is only ~4?. The AMP method is also used to calculate the orbit of the 17 Cyg FG pair, which has a period of 238 yrs, yielding results in good agreement with the orbits derived in other studies. The ephemerides of the obtained AMP orbits, the position data for the AF pair from the WDS catalog (11 positions during 1893–2002), and Pulkovo CCD observations for 2007–2013 are used to calculate the apparent motion parameters of AB–FG outer pair, as well as a family of close-to-parabolic orbits with periods of 3.7 million years ormore. All the orbits (for both the inner and the outer pairs) are steeply inclined to theGalactic plane. Monte Carlo simulations are used to compute the probability that the outer pair is gravitationally bound, which is 47%. The similarity of the proper motions and radial velocities of all the components provides evidence that they all belong to a single stellar stream. Data from the CNS3 catalog are used to compose a list of candidate members of this stream.     

Balanced cross-section restoration in a complicated folded hinterland structure: Shilbilisaj profile,Talas ridge,Caledonian Tien Shan

Conventional cross-section balancing techniques based on layer length measuring can be applied only for foreland structures. To analyse complicated hinterland structure with numerous small-scale folds, this balancing technique requires the reliable and detailed tracing of the morphology of any layer throughout the cross-section, which is unattainable. We present a special kinematic method of balancing cross sections based “on the geometry of the folded domain” which enables the structural restoration of hinterland regions. We apply the method to restore the detailed structural section along the Shilbilisaj River, having a length of 26 km. We divided this section into 40–60 so-called “domains” each including 2–7 folds. Our method uses the fold's morphology to determine the strain ellipsoid, which describes the deformation of each domain and is used to restore its pre-folded state. By combining the pre-folded states of the domains, we reconstruct the entire profile, and calculate shortening values as K = L₀/L₁ (initial to final length). The overall shortening value for the profile is 4.49, incrementally varying along the section from 3.79 to 5.53. The comparable results of two independently performed reconstructions emphasize the reliability of the applied balancing method.     

A dynamical study of the wide hierarchic triple star ADS 10288

We have performed the first dynamical study of the relative motions of the components of the wide hierarchic triple star system ADS 10288 (GL 649.1 = WDS 16579+4722), based on a 15-year series of photographic observations with the 26″ Pulkovo refractor, supplemented with data from the WDS catalog, HIPPARCOS parallaxes, and radial velocities of the components. The radial velocities were measured in Simeiz using the ILS stellar radial-velocity correlation spectrometer designed by A.A. Tokovinin. We applied the parameters of the apparent motion technique, which makes it possible to derive a binary’s orbit and mass from observations of a short arc, about 5°–10° in length. We derived preliminary orbits for the pairs AB and (AB)-C, whose orbital periods are 340 and 64 000 years, respectively. Mass estimates derived from the mass-luminosity relation are consistent with our dynamical estimates. We determined the orientation of the orbits in Galactic coordinates. The orbital planes are not coplanar, and are steeply inclined to the Galactic plane, as was the case in our earlier studies for most wide visual pairs we have studied.     

VST OmegaCAM difference image analysis

We present a modified version of the difference image analysis software developed by the OGLE collaboration (DIAPL) and its implementation within AstroWISE environment. Python interface and parallel execution are described. Examples of graphical output on simulated data set are presented. The tool will be used in VST surveys for photometric variability search.     

Zur Frage einer „dynamischen“ Prüfung von Magnetkompassen

Zusammenfassung Magnetkompasse auf durch Seegang bewegten Schiffen können Dauerauslenkungen aufweisen. Nach kurzer Erläuterung des Problems werden die Einrichtungen und Hilfsmittel zur Durchführung der dynamischen Prüfung von Magnetkompassen beschrieben, vorläufige Prüfungsergebnisse mitgeteilt und die sich daraus ergebenden Schlußfolgerungen gezogen.

---

On the problem of a dynamical testing of magnetic compasses

Summary Magnetic compasses on board of ships subjected to the motion of the sea are often liable to continuous deviations. After a short discussion of the problem, the installations and the aids in use for the performance of the dynamic investigations of magnetic compasses are described, preliminary results of the investigations are communicated and the conclusions arising from them are drawn.

---

Sur le problème d'une vérification »dynamique« des compas magnétiques

Résumé Des compas magnétiques à bord de bâtiments soumis aux mouvements de la mer subissent souvent des déviations permanentes. Après un bref exposé de ce problème on décrit les dispositifs et les moyens auxiliaires en usage pour l'examen dynamique de compas magnétiques; de plus, on en communique les résultats préliminaires et on tire les conclusions qui en découlent.

     

Photographic observations of visual double stars at Pulkovo: Digitization,measurement, and calibration

We present the results of determining the relative positions of 359 pairs of stars. More than 6000 photographic plates were obtained in 1960–2007 at the 26-inch refractor of the Pulkovo Observatory. The plates have been digitized with a Canon EOS 5D Mark II digital camera and a long-focus Jupiter 21M lens; the scalewas 21 μm/pixel. Themeasurements have been calibrated using a template digitized with the Belgian high-precision ROB Digitizer. The results have been thoroughly investigated for systematic errors. We have studied the scale of the 26-inch refractor and revealed its temperature and time dependences. The application of a new digitization, measurement, and calibration technique has allowed the accuracy to be increased compared to the past measurements. The single-exposure measurement accuracy is within the range from 2 to 70 mas, on average, 28 mas in both coordinates. The errors of the yearly mean positions are, on average, 8.7 mas in the angular separation and 0.05?. in the position angle.