Restoration of the proton density distribution in the Earth’s plasmasphere from measurements along the INTERBALL-1 satellite orbit

Based on experimental data obtained in 1995?C2000 on board the INTERBALL-1 spacecraft using the ALPHA-3 instrument, a semi-empirical two-dimensional model of the Earth plasmasphere is developed, which allows for the plasma distribution in the entire meridional plane to be restored from the temperature and proton density measurements along the satellite orbit. The model has also been tested using the data of the IMAGE spacecraft. The model uses theoretical expressions (Lemaire and Schere, 1974) that describe the plasma distribution in the plasmasphere for the cases of thermal equilibrium and collisionless initial partial filling of plasmaspheric shells; therefore, the parameters of the constructed model have a clear physical meaning and make it possible, in particular, to estimate the degree of plasmasphere filling.     

Observations of the Hα hydrogen emission on Spitsbergen during the proton event of January 22, 2012

The behavior of the Hα hydrogen emission at Barentsburg observatory during precipitation of high-energy solar protons and sudden impulse (SI) on January 22, 2012, was studied. The emission intensity was determined with a spectrometer, which gives the meridian arc spectrum image. It has been shown that the Hα emission luminosity onset coincides with SI and is caused by precipitation of solar wind protons through the cusp.     

Ion drift in the earth’s inner plasmasphere during magnetospheric disturbances and proton temperature dynamics

Based on the thermal plasma measurements in the Earth’s inner plasmasphere on the INTER-BALL-2 and MAGION-5 satellites it has been indicated that the plasmaspheric ion temperature as a rule decreases during the main phase of magnetic storms; in this case the plasma density increases or remains at the level typical of undisturbed conditions. The physical mechanism by which the ion drift during a magnetic storm results in a temperature decrease is described. It is shown that the third adiabatic invariant also remains in processes with a characteristic time shorter than the period of charged particle drift around the Earth for cold equatorial plasma. The constructed model of the drift shell displacement from the Earth caused by a decrease in the magnetic field in the inner magnetosphere during the development of a magnetic storm satisfactorily describes the decrease in the proton temperature near the equatorial plane.     

The atmospheric effects of October 2003 solar proton event simulated with the chemistry–climate model SOCOL using complete and parameterized ion chemistry

October 2003 solar proton events (SPE) is rather well covered by the observations; therefore its studies represent a good way for model validation and intercomparison. Here we apply chemistry–climate model (CCM) SOCOL with complete (SOCOLⁱ) and parameterized ion chemistry to evaluate the accuracy of a commonly used ion chemistry parameterization scheme. We performed ensemble experiments with and without SPE to characterize the effect of the October 2003 SPE on the NO_x, HO_x, ClO_x and O₃ in the middle atmosphere. Preliminary comparison of the simulated effects against MIPAS observations revealed rather good general agreement for most of the species. Comparison of the results obtained with complete and parameterized ion chemistry representation showed that the model with parameterized ion chemistry underestimates the effect of SPE on chemical composition of the middle atmosphere by up to 40% for NO_x and N₂O, up to 70% for HO_x and ClO_x and up to 600% for HNO₃. The parameterization is more accurate for ozone, however the model with parameterized ion chemistry underestimates ozone depletion by up to 15% during the SPE in the mesosphere and by 10% 2 weeks later in the stratosphere, which can be important for the long-term effects of SPE on the ozone layer.     

Influence of the atmospheric surface layer on the penetration of the electric field from the earth’s surface into the ionosphere

In the used model, the quasistationary electric field in the atmosphere of the Earth is obtained by solving the conductivity equation. The penetration characteristics of the electric field from the Earth’s surface into the ionosphere depend on both atmospheric and ionosphere conductivity. The ionosphere is taken into account by setting a special condition on the upper boundary of the atmosphere. The influence of the atmospheric surface layer with a reduced conductivity on the penetration of the electric field from the surface of the Earth into the ionosphere is analyzed.     

Hydrocarbons at the Geochemical Barrier the Northern Dvina–the White Sea

Water Resources - Aliphatic and polycyclic aromatic hydrocarbons have been studied in suspended matter and bottom sediments at the geochemical barrier the Northern Dvina–Dvina Bay during...     

Features in the Behavior of the Solar Wind behind the Bow Shock Front near the Boundary of the Earth’s Magnetosphere

Geomagnetism and Aeronomy - Macroscopic discontinuous structures observed in the solar wind are considered in the framework of magnetic hydrodynamics. The interaction of strong discontinuities is...     

Existence of the solutions and the attractors for the large-scale atmospheric equations

The atmosphere is a kind of fluid surrounding therotating earth, and its state can be described by thevelocity vector v, the temperature T, the density ρ, andthe pressure p at each point. Its evolution process isessentially governed by the Navier-Stockes equationand the temperature equation. Due to the specialty andthe complexity of the atmospheric problem, althoughsome modified and simplified work have made onthese fluid mechanics and temperature equations, theyare still a very complex forc…     

Does the Phaeocystis bloom affect the diel migration of the suprabenthos community?

The suprabenthos comprises all bottom-dependent animals, mainly crustaceans (including decapods and peracarids), which perform--with varying amplitude, intensity and regularity--seasonal or daily vertical migrations above the sea floor. The presence of organisms in the Benthic Boundary Layer is determined by two general factors: (1) organism behaviour, which depends on the light penetration in the water column and (2) boundary-layer hydrodynamics. In the coastal zone of the eastern English Channel, during the spring Phaeocystis bloom, the presence of gelatinous colonies modifies the penetration of light in the water column, which may seriously affect the abundance and/or the behaviour of the suprabenthos community. To clarify this point, 19 suprabenthic hauls were taken with a modified Macer-GIROQ sledge both during the day and during the night, from March to June 2002 (i.e., before, during and after the bloom). Two sites, located in the coastal and offshore areas of the Ophelia medium sand macrobenthic community were investigated. The bloom had no effect on species richness and abundance in either site. However, the diel migrations of some dominant species--such as the cumaceans Pseudocuma longicornis and Pseudocuma similis, the mysid Gastrosaccus spinifer and the amphipod Stenothoe marina--were modified. During the bloom, diurnal and nocturnal suprabenthic abundances were similar, and in the absence of bloom, species remained benthic during the day. The permanent presence of suprabenthic species in the Benthic Boundary Layer could have a consequence on their predation by fish (mainly juveniles which preferentially consume small crustaceans in their diet), unless fish behaviour and predation efficiency--especially for visual predators--are also disturbed by changes in light intensity.     

County Shelter Planning from the Perspective of the Demands of the Vulnerable?Based on the Survey of the 6·17 Changning Earthquake

县域避难场所规划建设薄弱,灾后老年人等避难弱者的需求不能得到充分满足。长宁“6·17”地震发生后,笔者赴灾区调研,对老人、妇女、儿童等避难弱者进行访谈,深入了解避难弱者的避难经历、对避难场所的认知及相关需求,总结避难弱者在灾后初期、中期、后期阶段的需求变化及对避难空间的诉求。在避难弱者需求视角下提出县域避难场所规划提升措施,包括建立避难弱者数据库、优化避难场所选址、提高避难场所建设标准、加强对避难弱者“定制化”的防灾宣传和避难引导等,以保障避难弱者的生命安全,提升避难生活质量。     

On the siltation of the middle Yangtze River

1 Origin, process and method of the research Silt deposition created the fertile Dongting and Jianghan Plains of the middle Yangtze drainage, but has become a main cause of the deteriorating flooding along the middle Yangtze. The history of flood and waterlog of the Yangtze River in last century, esp. the disastrous 1998 flood, has proved that the key to the Yangtze flood control is its middle reach, especially the Jingjiang Segment. To study the silt deposition of the middle Yangtze and …     

Seismotectonic destruction of the Earth’s crust in the zone of interaction of the northeastern side of the Baikal rift and the Aldan-Stanovoy block

The paper presents the modern structural-tectonic pattern and a tectonodynamic model of the zone of interaction of the most seismically active northeastern side of the Baikal rift zone (BRZ) and the conjugate system of seismogenic structures of the Aldan-Stanovoy block, where disastrous events with M ≥ 6.0 have been reported. Regularities in the structural formation of active faults and their kinematics are discussed. The faults form block structures accumulating significant tectonic strain. Motions between large tectonic blocks cause sudden release of the strain, which results in catastrophic events (M ≥ 6.0) with focal mechanisms of definite kinematic type.     

What determines the volume of the oceans?

The volume of Earth's oceans may be determined by a dynamic mechanism involving exchange of water between the crust and the mantle. Fast-spreading mid-ocean ridges are currently submerged to a depth at which the pressure is close to the critical pressure for seawater. This ensures optimal convective heat transport and, hence, maximal penetration of hydrothermal circulation along the ridge axes. The oceanic crust is hydrated to a depth of a kilometer or more and can therefore carry a substantial flux of water to the upper mantle when it is subducted. The current ingassing rate of water by this process is probably at least sufficient to balance the outgassing rate. If the oceans were shallower, as they may have been in the distant past, convective heat transport would be reduced and the depth of hydrothermal penetration and crustal hydration would decrease. Outgassing would exceed ingassing and ocean volume would increase. The system is self-stabilizing as long as the depth of the oceans does not exceed its present value. This mechanism could explain why continental freeboard has remained approximately constant since the Archean despite probable increases in continental area.     

Geochemical characteristics of the metapelites from the Xingxingxia group in the Eastern Segment of the Central Tianshan: Implications for the provenance and paleoweathering

Clastic sedimentary rocks record a number of in-formation about the compositions and paleoweathering conditions of the source areas, and the tectonic setting of the depositional basin[1―6]. The traditionallypetrological study commonly utilizes the major com-ponents (Quartz, Feldspar and Lithics) of the silici-clastic sedimentary rocks to investigate the source rock composition and tectonic setting[7]. However, thepetrological method is somewhat limited, because many of the mafic components f…     

On the relation of variations in the travel times of seismic waves with the changes in the speed of the Earth’s rotation

The results of long-term sounding of the lithosphere by seismic waves from the deep-focus Hindu Kush earthquakes are presented. The travel time series of the first longitudinal wave on a fixed base are constructed for six seismic observation stations (SS) located on the Russian Platform (the Obninsk SS), on the Siberian Platform (the Eltsovka SS), on the Cis-Ural Trough (the Arti SS), in the Central-Ural Megazone (the Sverdlovsk SS), in the Transbaikalia (the Bodaibo SS), and in the Northern Tien Shan (the Przhevalsk SS). The time series duration in years for these stations ranged from 1964–1970 to 2007. The travel time series of seismic waves for the stations indicated are characterized by multi-slope negative linear trends caused by changes in the stress-strain state of rocks. From the comparison of the trend slopes at different stations it follows that the changes in the stress conditions within the lithosphere are relatively weak in the aseismic regions of the Russian and Siberian Platforms and in the Ural Megazone, whereas in the seismically active regions of Tien Shan, Transbaikalia and the Cis-Ural Trough they are more pronounced. The correlation has been observed between the time series trends of the average annual travel times of seismic waves and the time series of the Earth’s rotation speed. The strongest correlation between the series can be seen for the stations, located on the platforms with weak manifestations of both seismicity and active geodynamic processes. Within the long-term periods of deceleration and acceleration of the Earth’s rotation, travel times of seismic waves are decreased and increased, respectively.     

The Akp-Btk value method and the results for the retrieval of the parameters of the Earth's free core nutation

The rotation of the Earth's liquid core creates the Nearly Diurnal Free Wobble (NDFW). It is one of the problems of researching the Earth's liquid core for us to retrieve the parameters of the Earth's Free Core Nutation (FCN), from the Earth's liquid core resonance of gravity tide waves on the diurnal frequency band. Since 1987, some scientists in many different countries have come to calculate the parameters of FCN by using the observational data of gravity tide waves on the diurnal frequency band. They basically followed the Stacking method, which needed five diurnal waves for the resolution. In this paper, authors introduced the Akp-Btk value method with clearly geometrical meaning as a new method, which only requires three very high signal-noise-ratio waves O1, K1 and P1 for the resolution. Authors chose the observational data of the three superconducting gravimeter stations respectively located in Cantley of Canada, Wuhan of China and Brussels of Belgium, to compute the parameters of FCN. It was the first time that the observational results of the parameters of FCN obtained from gravitational tide were in accord with the parameters of FCN gained from VLBI since 1987.     

Paleogeographic evolution of the Lower Yangtze region and the break of the “platform-slope-basin” pattern during the Late Ordovician

Wide distribution of the black shales and diversification of the graptolite fauna in South China during the Late Ordovician resulted from its unique paleogeographic pattern, which was significantly affected by the paleogeographic evolution of the Lower Yangtze region. In the study, 120 Upper Ordovician sections from the Lower Yangtze region were collected, and a unified biostratigraphic framework has been applied to these sections to establish a reliable stratigraphic subdivision and correlation. Under the unified time framework, we delineate the distribution area of each lithostratigraphic unit, outline the boundary between the sea and land, and reconstruct the paleogeographic pattern for each graptolite zone. The result indicates that, with the uplift and expansion of the ‘Jiangnan Oldland' in the beginning of the late Katian, the oldland extended into the Yangtze Sea gradually from south to north, which finally separate the Jiangnan Slope and the Yangtze Platform. Consequently,the longstanding paleogeographic pattern of "platform-slope-basin" in South China was broken. The paleogeographic change led to sedimentary differentiation among the two sides of the ‘Jiangnan Oldland' during the Late Ordovician. This event also led to the closure of the eastern exit of the Upper Yangtze Sea, and formed a semi-closed, limited and stagnant environment for the development of the organic-rich black shales during the Late Ordovician. The major controlling factors of these paleogeographic changes in the Lower Yangtze region were not consistent from the Katian to the Hirnantian. In the late Katian, the sedimentary differentiation between the east and west sides mostly resulted from regional tectonic movement-the Kwangsian Orogeny.However, during the Hirnantian, the whole Yangtze region became shallower, which was mostly influenced by the concentration of the Gondwana ice sheet and the consequent global sea level drop.     

Dynamical diagnosis of the breakup of the stratospheric polar vortex in the Northern Hemisphere

The research on climate change in polar regions, especially on the role of polar in the global climate system, has gain unprecedented level of interest. It has been the key scientific issue of the International Polar Year program (IPY, 2007―2008). In this paper, we dealt with the debate upon the breakup time of the stratospheric polar vortex in boreal spring. An observational study of the relation between strato- spheric polar vortex breakup and the extra-tropical circulation was performed. The mean breakup date―when the winter westerly at the core of polar jet turns to summer easterly―is about April 10. The breakup time has large interannual variation with a time span of about 2 months. It also has a long-term trend with the 1990s and 2000s witnessing more and more late breakups of polar vortex. Composite of wind speed at the core of polar jet for the extremely early and late breakup years shows that late years have two periods of westerly weakening while early breakup years have only one. The first weakening in the late years happens in middle January with wind speed dropping sharply from more than 40 m s?1 to about 15 m s?1. This is accompanied with anomalous activities of planetary waves in both strato- sphere and troposphere; while the second weakening in the late breaking years is mainly the results of diabatic heating with very weak wave activities. In early breakup years, the transition from westerly to easterly is rapid with wind speed dropping from more than 30 m s?1 to less than ?10 m s?1 within a month. This evolution is associated with a strong bidirectional dynamical coupling of the stratosphere and troposphere. The circulation anomalies at low troposphere are also analyzed in the extremely early and late breakup years. It shows that there are significant differences between the two kinds of extreme years in the geopotential height and temperature composite analysis, indicating the dynamical cou- pling of stratosphere and troposphere with the evolution of stratospheric polar vortex.     

Characteristics of the Activity of the Lintong-Chang＇an Fault in the Late Pleistocene

Analysis of fault outcrops and trench sections indicates fault displacements of 0.2m - 6.0 m on the bottom paleosol layer of the Epipleistocene with the maximum rate of 0.047 mm/a and an average displacement of 1.1 meters. The activity appears as fissures on the fault surface in the late Epipleistocene and there is no obvious displacement. The fault activity is weak and the most active segment is the Bailuyuan segment.     

Determining the thickness of the low-latitude boundary layer in the Earth’s magnetosphere

We describe a method for determining the thickness of the low-latitude boundary layer (LLBL) of the Earth’s magnetosphere at the dayside near the equatorial plane based on the data gathered by a single satellite that traverses the layer and measures the plasma velocity. The method may be applied when the position of the magnetopause and the magnetosheath parameters fluctuate. The necessity of taking the presence of outer and inner LLBL regions into account is analyzed. The developed method is tested using the analysis results of two almost simultaneous close traverses of the magnetopause completed by the THEMIS mission satellites that provided relatively precise data on the LLBL thickness. It is shown that the developed method makes it possible to determine the LLBL thickness with an accuracy of ～10%.