Theoretical interpretation of cosmic magnetic fields

The paper discusses the possibilty of interpreting the magnetic fields of astronomical bodies in the framework of a unified field theory.Using one of the solutions of the generalized field theory, a direct relation between the polar magnetic field, the angular velocity and the gravitational potential of the body considered, is obtained. The geometric model used for applications has spherical symmetry and is of the type (FIGI).The predictions of the theoretical formula, obtained from the model, are compared with available observational data, and with the empirical formula of Blackett. The theoretical formula gives a possible interpretation of a seed magnetic field which will develop and produce the large-scale magnetic field observed for celestial objects. The formula shows that the field is generated as a result of rotation of a massive object.     

Polarization characteristics of Jensch coelostat

The polarization characteristics of the Jensch coelostat, used at the Sayan observatory, are presented. Results of calculations of the instrumental polarization (IP) are compared with the observations. It is shown that structural features of the Jensch coelostat lead to a very important dependence of the Stokes's parameters, that characterize the IP, on solar coordinates.     

Night Sky Brightness and Colour at Different Zenith Distances at Abu-Simbel Site

Photoelectric observations of night sky brightness at different zenith distances in blue, yellow and red colours have been carried out at Abu-Simbel site. Variations in the night sky brightness and (B-V) colour index with time are detected. These variations have been explained by the change of the galactic latitude of the observed point with time. The deduced results of night sky brightness have been compared with that obtained before at other sites. It has been found for both blue and yellow colours, that Abu-Simbel is the darkest site especially for zenith distances equal or greater than 60°. The present values of night sky brightness and colour have been obtained for the first time at Abu-Simbel site. The average night sky brightness at the galactic plane is 22.58 mag/arc sec² for blue and 21.66 mag/arc sec² for yellow. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of soil structure on soil fauna in a desert wadi in Southern Egypt

This study investigates the soil fauna in a part of the rainless desert of southern Egypt. Three sites were examined: two downstream of Wadi Allaqi, both of which have been inundated by the water of Lake Nasser for several years. The third site is in Wadi Quleib, a principal tributary of Wadi Allaqi which was not inundated. Soil fauna were collected by pitfall traps during April-November 1989. Data were treated by multivariate analysis techniques, including correspondence analysis and ascending hierarchic classification. Most species were Arthropoda, particularly Coleoptera (7 species). Wadi Quleib was richer than Wadi Allaqi both in number of species and density. In Wadi Allaqi, the first site was richer than the second, both in species and density. These differences are partially related to differences in soft texture between Wadi Quleib and Wadi Allaqi, and to the presence of dense groves of Tamarix nilotica in the first site of Wadi Allaqi.     

High-Performance Parallel Solver for Integral Equations of Electromagnetics Based on Galerkin Method

A new parallel solver for the volumetric integral equations (IE) of electrodynamics is presented. The solver is based on the Galerkin method, which ensures convergent numerical solution. The main features include: (i) memory usage eight times lower compared with analogous IE-based algorithms, without additional restrictions on the background media; (ii) accurate and stable method to compute matrix coefficients corresponding to the IE; and (iii) high degree of parallelism. The solver’s computational efficiency is demonstrated on a problem of magnetotelluric sounding of media with large conductivity contrast, revealing good agreement with results obtained using the second-order finite-element method. Due to the effective approach to parallelization and distributed data storage, the program exhibits perfect scalability on different hardware platforms.     

The Arctic Coastal Dynamics Database: A New Classification Scheme and Statistics on Arctic Permafrost Coastlines

Arctic permafrost coasts are sensitive to changing climate. The lengthening open water season and the increasing open water area are likely to induce greater erosion and threaten community and industry infrastructure as well as dramatically change nutrient pathways in the near-shore zone. The shallow, mediterranean Arctic Ocean is likely to be strongly affected by changes in currently poorly observed arctic coastal dynamics. We present a geomorphological classification scheme for the arctic coast, with 101,447?km of coastline in 1,315 segments. The average rate of erosion for the arctic coast is 0.5?m? year^?1 with high local and regional variability. Highest rates are observed in the Laptev, East Siberian, and Beaufort Seas. Strong spatial variability in associated database bluff height, ground carbon and ice content, and coastline movement highlights the need to estimate the relative importance of shifting coastal fluxes to the Arctic Ocean at multiple spatial scales.     

KREEPy lunar meteorite Dhofar 287A: A new lunar mare basalt

Abstract— Dhofar 287 (Dho 287) is a new lunar meteorite, found in Oman on January 14, 2001. The main portion of this meteorite (Dho 287A) consists of a mare basalt, while a smaller portion of breccia (Dho 287B) is attached on the side. Dho 287A is only the fourth crystalline mare basalt meteorite found on Earth to date and is the subject of the present study. The basalt consists mainly of phenocrysts of olivine and pyroxene set in a finer‐grained matrix, which is composed of elongated pyroxene and plagioclase crystals radiating from a common nucleii. The majority of olivine and pyroxene grains are zoned, from core to rim, in terms of Fe and Mg. Accessory minerals include ilmenite, chromite, ulvöspinel, troilite, and FeNi metal. Chromite is invariably mantled by ulvöspinel. This rock is unusually rich in late‐stage mesostasis, composed largely of fayalite, Si‐K‐Ba‐rich glass, fluorapatite, and whitlockite. In texture and mineralogy, Dho 287A is a low‐Ti mare basalt, with similarities to Apollo 12 (A‐12) and Apollo 15 (A‐15) basalts. However, all plagioclase is now present as maskelynite, and its composition is atypical for known low‐Ti mare basalts. The Fe to Mn ratios of olivine and pyroxene, the presence of FeNi metal, and the bulk‐rock oxygen isotopic ratios, along with several other petrological features, are evidence for the lunar origin for this meteorite. Whole‐rock composition further confirms the similarity of Dho 287A with A‐12 and A‐15 samples but requires possible KREEP assimilation to account for its rare‐earth‐element (REE) contents. Cooling‐rate estimates, based on Fo zonation in olivine, yield values of 0.2–0.8°C/hr for the lava, typical for the center of a 10–20 m thick flow. The recalculated major‐element concentrations, after removing 10–15% modal olivine, are comparable to typical A‐15 mare basalts. Crystallization modeling of the recalculated Dho 287A bulk‐composition yields a reasonable fit between predicted and observed mineral abundances and compositions.     

Social and Geographic Contexts of Water Concerns in Utah

Public concerns about water issues are key considerations in responding to changing hydrologic conditions. Literature is mixed on the social profiles associated with resource-related risks. Using data from a household survey, we compare concerns about water shortage, climate change impacts on water supply, poor water quality, and flooding. We assess the combined influence of social and locational factors on each concern and variations across three valleys in northern Utah. Generalized linear mixed modeling is used, given the ordinal nature of most variables. Water shortage was the greatest concern, and female, older, nonwhite, and recreationally active respondents were generally more concerned about water issues than their counterparts. Education, income, and religious identity presented more complicated relationships with water concerns, with significant interaction effects with valley geography. This study has implications for improving public involvement in risk management and engendering support for future water policy and planning strategies to address these risks.     

Decline in Length of the Summer Season on the Kola Peninsula, Russia

By analysing records made in the northern taiga forests of the Lapland Reserve (Kola Peninsula, Russia) during 1930–1998, we unexpectedly discovered a decline in the length of the snow-free and ice-free periods by 15–20 days due to both delayed spring and advanced autumn/winter. Respective seasonal temperatures best explained the dates of all phenological phases: 1 °C shift in temperature was approximately equal to 2–5 day shift in phenology. However the phenological shiftsduring the observation period are much larger than could be expected from the slight (0.56 °C) drop in temperatures during August–September, suggesting that the biotic effects of a very slight cooling have been enhanced by one or more unknown factors. Although emissions of sulphur dioxide from the nickel-copper smelter at Monchegorsk may have contributed to the observed trend (via changes in regional radiative budget), we found no evidence of direct pollution impact on dates of birch autumnal coloration or birch leaf fall, which exhibited the largest (22 days) shift between 1930 and 1998. The detected phenological trends agree with an increase in winter (snow) precipitation in the study area by 44%; however, effects of precipitation on any of the investigated phenological phases were far from significant. Our results highlight the importance of phenological records for the assessment of past regional environmental changes, and demonstrates that the prediction of even the simplest biotic responses to the Global Changes requires a profound understanding of the interactive impact of abiotic factors on the ecosystem.