Solar abundance determination from ultraviolet emission lines

The intensities of far ultraviolet emission lines from the solar corona are analyzed to determine relative coronal abundances for oxygen, silicon, and iron. Dielectronic recombination is included in the formulation of ionization equilibrium. Observations of solar radio emission are used to obtain abundances relative to hydrogen. The absolute coronal abundances appear to be in agreement with their respective photospheric values. General properties of the structure of the chromosphere and corona are deduced from the analysis of observed emission in the ultraviolet and radio wavelength regions.     

Diffuse Component Spectra of Solar Active Regions at Submillimeter Wavelengths

Solar maps at 212 and 405 GHz obtained by the Solar Submillimetric Telescope (SST) show regions of enhanced brightness temperature, which coincide with the location of active regions. A statistical study of the radio emission from these active regions was performed for the first time at such high frequencies during 23 days on June and July 2002, when the atmospheric opacity was low. The brightest regions on the maps were chosen for this study, where the brightness excess observed varies from 3 to 20% above quiet Sun levels (i.e., 200–1000 K) at both wavelengths. Sizes of the regions of enhanced emission calculated at half the maximum value were estimated to be between 2′ and 7′. These sizes agree with observed sizes of active regions at other wavelengths such as Hα and ultraviolet. An important result is that the flux density spectra of all sources increase toward submillimeter frequencies, yielding flux density spectral index with an average value of 2.0. The flux density of the active region sources were complemented with that from maps at 17 and 34 GHz from the Nobeyama Radio Heliograph. The resulting spectra at all four frequencies were fit considering the flux density to be due to thermal bremsstrahlung from the active region. In the calculations, the source radius was assumed to be the mean of the measured values at 212 and 405 K. The effective temperatures of the radio emitting source, assumed homogeneous, obtained from this fit were 0.6–2.9 × 10⁴ K, for source diameters of 2′–7′.     

Source ambiguity from an estimation of the scaling exponent of potential field power spectra

An analysis of the field scaling power spectrum yields useful information about the source distribution, but it is uncertain whether deterministic, random, fractal or mixed approaches have to be used for the interpretation. To this end, the scaling properties of potential field spectra are analysed for a number of different source models of geological interest. Besides the models of Naidu (purely random sources) and Spector and Grant (gross block statistical ensembles) we consider other types of density and magnetization distributions with spectral exponents in the fractal range, such as a single homogeneous body with a random white source distribution. Spectral slopes in the fractal range are obtained.
We also study the effects of important natural sources, such as salt domes and sedimentary basins, representing them with simple Gaussians or combinations of Gaussian signals. The same spectral slopes as for gravity signals generated by 3-D fractal source distributions are found for them. Hence the power law decay of the field is not a characteristic only of fractal source models.
If a 3-D fractal source distribution is assumed a priori , a way of verifying the goodness of the model is to examine the whitened field at source level. The probability that the whitened field derives from a random white population is estimated for synthetic and real anomalies by applying the usual statistical tests.     

Role of land surface parameterizations on modeling cold-pooling events and low-level jets

Land surface parameterization schemes play a significant role in the accuracy of meso-local scale numerical models by accounting for the exchange of energy and water between the soil and the atmosphere. The role of land surface processes during large-scale cold-pooling events was studied with two land surface schemes (LSMs) in the Advanced Research Weather Forecasting model (ARW). Model evaluation was complex due to the surface and boundary layer interactions at different temporal and spatial scales as revealed by a scale dependent variance analysis. Wavelet analysis was used for the first time to analyze the model errors with specific focus on land surface processes. The ARW model was also evaluated for the formation of a low-level jet (LLJ). It is shown that vertical resolution in the model boundary layer played a significant role in determining the characteristics of LLJ, which influenced the lower boundary layer structure and moisture distribution. The results showed that the simulated low-level jet over southern Georgia was sensitive to the land surface parameterization and led to a significant difference in the boundary layer exchange. The jet shear played a crucial role in the maintenance of turbulence and weak shear caused excessive radiative cooling leading to unrealistic cold pools in the model. The results are important for regional downscaling as the excessive cold pools that are simulated in the model can go unnoticed.     

Ecosystem-based marine spatial management: Review of concepts, policies, tools, and critical issues

Conventional sectoral management and piecemeal governance are considered less and less appropriate in pursuit of sustainable development. Ecosystem based marine spatial management (EB-MSM) is an approach that recognizes the full array of interactions within an ecosystem, including human uses, rather than considering single issues, species, or ecosystem services in isolation. Marine spatial planning and ocean zoning are emerging concepts that can support EB-MSM. EB-MSM is driven by high-level goals that managers aim to achieve through the implementation of measures. High-level goals and objectives need to be translated into more operational objectives before specific targets, limits and measures can be elaborated.Monitoring, evaluation and adaptation are necessary to ensure that marine management measures are both effective and efficient. Solid monitoring frameworks are the foundation of adaptive management, as they provide the necessary information to evaluate performance and the effectiveness of management actions. Marine protected areas (MPAs) - possibly set up in networks - constitute a key component in EB-MSM policies and practises and have been applied as a cornerstone in conservation of marine biodiversity, management of fish populations, development of coastal tourism, etc. Moreover, MPA experiences have provided methods and concepts (such as zoning) to a wider EB-MSM context. The assignment of values to biophysical features of the marine environment allows the direct assessment of related management choices and may assist EB-MSM.A range of monetary valuation techniques have been proposed to reduce attributes of goods and services to a single metric. However, in the marine environment such an approach is often over simplistic, and thus less reductive techniques may be necessary. Rather than producing a single metric, the results of non-monetary assessments guide policy allowing weight to be given as necessary to potential areas of conflict and consensus.Strategies to take into account climate change effects and geohazard risks in EB-MSM have been applied or proposed worldwide. EB-MSM regimes must be alert to such risks and flexible to account for changes.     

Studies of multiple stellar systems – IV. The triple-lined spectroscopic system Gliese 644

We present a radial velocity study of the triple-lined system Gliese 644 and derive spectroscopic elements for the inner and outer orbits with periods of 2.965 5 and 627 d. We also utilize old visual data, as well as modern speckle and adaptive optics observations, to derive a new astrometric solution for the outer orbit. These two orbits together allow us to derive masses for each of the three components in the system: M _A=0.410±0.028 (6.9 per cent), M _Ba=0.336±0.016 (4.7 per cent), and M _Bb=0.304±0.014 (4.7 per cent) M_⊙. We suggest that the relative inclination of the two orbits is very small. Our individual masses and spectroscopic light ratios for the three M stars in the Gliese 644 system provide three points for the mass–luminosity relation near the bottom of the main sequence, where the relation is poorly determined. These three points agree well with theoretical models for solar metallicity and an age of 5 Gyr. Our radial velocities for Gliese 643 and vB 8, two common proper motion companions of Gliese 644, support the interpretation that all five M stars are moving together in a physically bound group. We discuss possible scenarios for the formation and evolution of this configuration, such as the formation of all five stars in a sequence of fragmentation events leading directly to the hierarchical configuration now observed, versus formation in a small N cluster with subsequent dynamical evolution into the present hierarchical configuration.     

The Unbearable Closeness of The East: Embodied Micro-Economies of Difference,Belonging, and Intersecting Marginalities in Post-Socialist Berlin

Abstract

This article examines the micro-politics of belonging in the post-socialist outskirts of Berlin, in Marzahn, one of many new urban immigrant settlement areas in Europe. More specifically, it focuses on what locals perceive as an acceptance-precluding conspicuous presence of nominally white immigrants of German ancestry from the former Soviet Union, the Aussiedler (resettlers). Long-term residents read and interpret these immigrants’ everyday embodiments by constructing what I call micro-economies of embodied difference in order to mark immigrants as non-belonging Eastern-European. In order to make sense of such practices and local antipathy towards the Aussiedler, I analyze the embeddedness of this suburban locality in the regional politics of belonging, showing how Marzahn and its long-time residents have themselves become post-wall Berlin's (and Germany's) internal Others, saturated with uncommodifiable traces of now-denigrated state-socialist Easternness. I suggest that in such a context these residents’ practice of ascribing the unwanted Easternness to recent immigrants works to deflect it in order to buttress their own claims to full membership citizenship in the unified Germany from which they have long been excluded. [Key words: belonging, immigrants, embodied difference, Othering, Easternness, Berlin.]     

Delineation of mafic intrusions near Bedford (Virginia,USA) using geological and geophysical methods

In the present work, geological and geophysical methods were used to delineate the locations of multiple mafic intrusions at the Claytor Nature Study Center (CNSC) near Bedford, VA. An investigation of the groundwater hydrology of CNSC was launched in 2007. As a first step in that project a preliminary geological survey revealed sparse evidence of a number of diabase intrusions in the area. While diabase intrusions are not particularly permeable features, contact metamorphism of the host rock could provide conduits for groundwater due to stress fractures and joints and high-temperature recrystallization of the rock matrix. Following the geological survey, geophysical surveys including seismic refraction, ground penetrating radar, and magnetic ground measurements were conducted to determine the location and extent of these multiple igneous intrusions. Seismic and radar surveys proved to be inconclusive, but the magnetic surveys showed strong magnetic anomalies. The magnetic data were obtained using a Geometrics G-856 proton precession magnetometer and were interpreted using the Mag2dc algorithm and SGeMS geostatistical software. The results show that the intrusions are dikes that cut across nearly perpendicular to the regional metamorphic structures and trend generally north–south with a dip of approximately 75°–90° to the west. These findings are consistent with one of the general directions of stresses associated with the North Atlantic seafloor spreading in late Triassic or early Jurassic period. Subsequent hydrologic testing and groundwater modeling confirm the role of the dikes in the overall hydrogeology of the site.