The Relationship among Geodynamics,Heat Flow,Deep Structure,and the Oil and Gas Potential of Yamal

Doklady Earth Sciences - The amount of hydrocarbon deposits per unit area of Yamal Peninsula is more than 100 times as much as the global average. The hydrocarbon deposits are generally situated in...     

Characterization of oil pollution around the oil rocks production site in the Caspian Sea using spaceborne polarimetric SAR imagery

Based on the processing and analysis of radar imagery received by the Radarsat-2 satellite in summer 2009 over the Oil Rocks (Neftyanyye Kamni or Neft Dashlari) oil production site in the Caspian Sea, it is shown that the images are full-fledged products, making it possible to retrieve information on the oil pollution and, under certain assumptions, estimate volumes of industrial oil spills. To map the space-time distribution of oil patches, the wide-swath mode of the Radarsat-2 synthetic aperture radar (SAR) with vertical VV polarization of signal is most suitable. The polarimetric regime itself does not improve the identification of oil pollution. The special quad-polarization mode in these experiments has not showed substantial advantages; the maximum contrasts were observed at vertical polarization. Estimates of oil spills volumes are obtained.     

Estimation of the effective recombination coefficient by variations in the maximum usable frequencies of one-hop high-frequency radio lines during the solar eclipses of March 29, 2006, and August 1, 2008

This paper presents the results of experimental investigations of variations in maximal usable frequencies (MUFs) during solar eclipses with the use of the method of panoramic tilt sounding by chirps in Eastern Europe and Western Siberia. The characteristics of perturbations of MUFs have been obtained experimentally. It has been established that the effective recombination coefficient increases by 24% in the ionospheric F region with an increase in the maximum eclipse phase from 0.49 to 1.0.     

Displacement of large-scale open solar magnetic fields from the zone of active longitudes and the heliospheric storm of November 3–10, 2004: 1. The field dynamics and solar activity

The dynamics of the large-scale open field and solar activity at the second stage of the MHD process, including the origination and disappearance of the four-sector structure during the decline phase of cycle 23 (the stage when the blocking field is displaced from the main zone of active longitudes), has been considered. Extremely fast changes in the scales of one of new sectors (from an extremely small sector (“singularity”) to a usual sector that originated after the uniform expansion (“explosion”) of singularity with a “kick” into the zone of active longitudes, westward motion of the MHD disturbance front in the direction of solar rotation, and formation of an active quasi-rigidly corotating sector boundary responsible for the heliospheric storm of November 2004) have been detected in the field dynamics. It has been indicated that a very powerful group of sunspots AR 10656 (which disappeared after the explosion) with an area of up to 1540 ppmh (part per million hemisphere), a considerable deficit of the external energy release, and zero geoeffectiveness in spite of the closeness to the Earth helioprojection existed within singularity. It has been assumed that the energy escaped from this group with effort owing to the interaction between coronal ejections and narrow sector walls (singularity), and a considerable part of the energy was released in the outer layers of the convective zone, as a result of which singularity exploded and this explosion was accompanied by the above effects in the large-scale field and solar activity.     

Fluctuations of total electron content in the ionosphere as deduced from measurements by single-frequency GPS receivers

Using an ionospheric diagnostic technique developed by the authors and single-frequency GPS receivers, we obtained the first results of these diagnostics. In particular, we show that the ionosphere is characterized by large-scale periodic processes with frequencies of 3–5 mHz.     

Superconcentration of photospheric sources of the large-scale open solar magnetic field in the main zone of active longitudes,blocking of differential rotation,and origination of the four-sector structure: 2. Geoeffectiveness

The effectiveness of the series of powerful heliospheric storms, originated during the decline phase of cycle 23 owing to the superconcentration of the open field photospheric sources in the main zone of active longitudes, has been studied. The geoeffectiveness of the storm of July 16—27, 2004, was closely related to the origination of the four-sector structure and depended on the destabilization of two activity centers weakly and strongly geoeffective with ARs 10649 and 10652. The first center was localized in one of the new sectors; the second center, in the western surroundings of the zone of active longitudes. The departure of coronal mass ejections from AR 10649 was substantially hindered: they were completely absent after the series of powerful X-ray flares, and a rare phenomenon of “sunquake” was observed: shock waves did not reach the Earth in spite of its favorable position. The Earth was strongly shielded by new sector boundaries from coronal ejections from AR 10652 with a gradual weakening and disappearance of this region, as a result of which the cascade of three near-Earth storms with an increasing power and Ap, indices of 52, 154, and 186 originated. Rare phenomena in AR 10649 and the cascade of solar—terrestrial heliospheric storms made the storm of July 16— 27 a unique phenomenon in cycle 23, and a short-term prediction of its geoeffectiveness was impossible.     

Zinc in natural waters in the Selenga River basin

Concentrations of Zn in the surface (river and lake) and subsurface waters are assessed in the basin of the Selenga River—the main tributary into Lake Baikal. Specific geographical features are revealed in Zn distributions in natural waters, which are determined by different Zn concentrations in drained rocks and soils and by the geochemical redox conditions of Zn migration. Areas with low, medium, and relatively high Zn concentrations (as compared with their Clarke concentrations) are determined.     

Map of Anthropogenic Soil Erosion of Russia

Doklady Earth Sciences - The last map of anthropogenic soil erosion in Russia was compiled more than 20 years ago on a scale of 1 : 5 000 000. In recent years, additional data on soil...     

Latitude and Power Characteristics of Solar Activity at the End of the Maunder Minimum

Two important sources of information about sunspots in the Maunder minimum are the Spörer catalog (Spörer, 1889) and observations of the Paris observatory (Ribes and Nesme-Ribes, 1993), which cover in total the last quarter of the 17th and the first two decades of the 18th century. These data, in particular, contain information about sunspot latitudes. As we showed in (Ivanov et al., 2011; Ivanov and Miletsky, 2016), dispersions of sunspot latitude distributions are tightly related to sunspot indices, and we can estimate the level of solar activity in the past using a method which is not based on direct calculation of sunspots and weakly affected by loss of observational data. The latitude distributions of sunspots in the time of transition from the Maunder minimum to the regular regime of solar activity proved to be wide enough. It gives evidences in favor of, first, not very low cycle no.–3 (1712–1723) with the Wolf number in maximum W = 100 ± 50, and, second, nonzero activity in the maximum of cycle no.–4 (1700–1711) W = 60 ± 45. Therefore, the latitude distributions in the end of the Maunder minimum are in better agreement with the traditional Wolf numbers and new revisited indices of activity SN and GN (Clette et al., 2014; Svalgaard and Schatten, 2016) than with the GSN (Hoyt and Schatten, 1998); the latter provide much lower level of activity in this epoch.     

Features of resonance structures in natural electromagnetic noise spectra in the region of the main ionospheric trough

The paper presents the results of studies of the resonance structures of the background electromagnetic noise spectrum obtained in a series of experiments in the autumn of 2012 in Karelia. The experiments are unique because the background noise was detected at stations spaced by a distance much less than the doubled effective waveguide height (about 50 km) in a region close to the main ionospheric trough, the structure and position of which were determined based on radiotomographic data. It is shown that the dimensions of the ionospheric local region, which affects both the generation of spectral resonance structures in particular and the propagation of electromagnetic waves in the considered range in general, depend significantly on the variation of ionospheric parameters in regions with strong horizontal inhomogeneity.