Identification of seismic activity sources on the subsatellite track by ionospheric plasma disturbances detected with the Sich-2 onboard probes

Using a cylindrical Langmuir probe and the authors’ proprietary two-channel pressure transducer, ionospheric plasma parameter distributions along the orbit of the Sich-2 satellite (Ukraine, 2011–2012) were measured. This paper is concerned with identifying the space–time location of ionospheric plasma disturbance sources, including the epicenters of actual earthquakes (before or during the satellite flyover) and incipient earthquakes on the subsatellite track, from the measured distributions of the electron density and temperature and the neutral particle temperature along the satellite orbit. To do this, the measured ionospheric plasma parameter distributions are connected to the coordinates on the subsatellite track.It is shown that local disturbances in the electron density and temperature and neutral particle temperature distributions in the satellite orbit in the ionosphere may serve as indicators of seismic activity on the subsatellite track. The epicenters of incipient earthquakes may be set off from other plasma parameter disturbance sources associated with seismic activity using information provided by special monitoring and survey centers that monitor the current seismic situation.     

A preliminary survey of non-lichenized fungi cultured from the hyperarid Atacama Desert of Chile

The Atacama Desert is one of the driest environments on Earth, and has been so for over 200,000 years. Previous reports have suggested that surprisingly low numbers of culturable bacteria, counted as biomass or species diversity, are present in Atacama sands collected from the most hyperarid regions. In previous studies, the presence of eukaryotic organisms was not discussed. In this report, we describe a method of direct plating onto rich media that resulted in culturing a range of fungi from Atacama samples. All fungi identified in this preliminary survey are spore-forming saprobes that are readily dispersed by wind, a likely mechanism that accounts for their presence in the central Atacama Desert.     

Peculiarities of the nighttime winter foF2 increase over Irkutsk

An analysis of properties and peculiarities of the nighttime winter foF2 increases (NWI) in the East Siberia is made on data of ionospheric station Irkutsk in the periods 1958–1992 and 2002–2009 and the empirical model of the F2 layer critical frequency under the geomagnetic quiet conditions deduced from these data (model Q-F2). It is revealed, that the NWI is the stable regularity of the quiet ionosphere over Irkutsk. The amplitude of the NWI (the difference between maximum and minimum foF2 values at night hours) is the greatest in December–January and nearly the same at low and middle solar activity. It is a peculiarity of the quiet ionosphere in the East Siberia. Maximum in night foF2 under quiet geomagnetic conditions is observed mainly after midnight (02-04 LT) and is shifted to predawn hours as solar activity increases. At low solar activity the quiet ionosphere at ∼02–04 LT shows the following properties: (a) the fluctuations of foF2 and hmF2 are in the reverse correlation but this dependence is weak; (b) very strong fluctuations of foF2 (|δfoF2| > 30%) occur seldom (∼4% of events) and almost all of them are positive; an example of very strong fluctuations of foF2 up to 60% can be an extreme increase in the foF2 on 19.12.2008; (c) the very strong enhancements of foF2 in the NWI maximum can be observed at the low geomagnetic activity, they occur more often during substorms but very seldom during geomagnetic storms. Possible reasons of these properties of NWI are discussed.     

GNSS water vapour tomography – Expected improvements by combining GPS,GLONASS and Galileo observations

The German Research Centre for Geosciences (GFZ) operates a GNSS water vapour tomography system using about 350 German GNSS stations. The GNSS data processing at the GFZ works in near real-time and provides zenith total delays, integrated water vapour and slant delay data operationally. This large data set of more than 50,000 slant delays per hour is used to reconstruct spatially resolved humidity fields by means of tomographic techniques. It can be expected that additional observations from the future Galileo system provide more information with improved quality. A simulation study covering 12 h at 14 July 2009 was therefore started to estimate the impact of GPS, Galileo and GLONASS data on the GNSS tomography. It is shown that the spatial coverage of the atmosphere with slant paths is highly improved by combining observations from two or three satellite systems. Equally important for a reliable tomographic reconstruction is the distribution of slant path intersections as they are required to locate the integrated delay information. The number of intersection points can be increased by a factor of 4 or 8 if two or three systems are combined and their distribution will cover larger regions of the atmosphere. The combined data sets can be used to increase the spatiotemporal resolution of the reconstructed humidity fields up to 30 km horizontally, 300 m vertically and 15 min. The reconstruction quality could not be improved considerably using the currently available techniques.     

Recent Progress in Physics-Based Models of the Plasmasphere

We describe recent progress in physics-based models of the plasmasphere using the fluid and the kinetic approaches. Global modeling of the dynamics and influence of the plasmasphere is presented. Results from global plasmasphere simulations are used to understand and quantify (i) the electric potential pattern and evolution during geomagnetic storms, and (ii) the influence of the plasmasphere on the excitation of electromagnetic ion cyclotron (EMIC) waves and precipitation of energetic ions in the inner magnetosphere. The interactions of the plasmasphere with the ionosphere and the other regions of the magnetosphere are pointed out. We show the results of simulations for the formation of the plasmapause and discuss the influence of plasmaspheric wind and of ultra low frequency (ULF) waves for transport of plasmaspheric material. Theoretical models used to describe the electric field and plasma distribution in the plasmasphere are presented. Model predictions are compared to recent Cluster and Image observations, but also to results of earlier models and satellite observations.     

Development of a GNSS water vapour tomography system using algebraic reconstruction techniques

A GNSS water vapour tomography system developed to reconstruct spatially resolved humidity fields in the troposphere is described. The tomography system was designed to process the slant path delays of about 270 German GNSS stations in near real-time with a temporal resolution of 30 min, a horizontal resolution of 40 km and a vertical resolution of 500 m or better. After a short introduction to the GPS slant delay processing the framework of the GNSS tomography is described in detail. Different implementations of the iterative algebraic reconstruction techniques (ART) used to invert the linear inverse problem are discussed. It was found that the multiplicative techniques (MART) provide the best results with least processing time, i.e., a tomographic reconstruction of about 26,000 slant delays on a 8280 cell grid can be obtained in less than 10 min. Different iterative reconstruction techniques are compared with respect to their convergence behaviour and some numerical parameters. The inversion can be considerably stabilized by using additional non-GNSS observations and implementing various constraints. Different strategies for initialising the tomography and utilizing extra information are discussed. At last an example of a reconstructed field of the wet refractivity is presented and compared to the corresponding distribution of the integrated water vapour, an analysis of a numerical weather model (COSMO-DE) and some radiosonde profiles.     

The structure of resting bacterial populations in soil and subsoil permafrost

The structure of individual cells in microbial populations in situ of the Arctic and Antarctic permafrost was studied by scanning and transmission electron microscopy methods and compared with that of cyst-like resting forms generated under special conditions by the non-spore-forming bacteria Arthrobacter and Micrococcus isolated from the permafrost. Electron microscopy examination of microorganisms in situ revealed several types of bacterial cells having no signs of damage, including "dwarf" curved forms similar to nanoforms. Intact bacterial cells in situ and frozen cultures of the permafrost isolates differed from vegetative cells by thickened cell walls, the altered structure of cytoplasm, and the compact nucleoid, and were similar in these features to cyst-like resting forms of non-spore-forming "permafrost" bacterial strains of Arthrobacter and Micrococcus spp. Cyst-like cells, being resistant to adverse external factors, are regarded as being responsible for survival of the non-spore-formers under prolonged exposure to subzero temperatures and can be a target to search for living microorganisms in natural environments both on the Earth and on extraterrestrial bodies.     

Response of the mesopause temperatures to solar activity over Yakutia in 1999–2013

OH(6-2) rotational temperature trends and solar cycle effects are studied. Observations were carried out at the Maimaga station (63.04°N, 129.51°E) for the period August 1999 to March 2013. Measurements were conducted with an infrared spectrograph. Temperatures were determined from intensity ratios in the P branch of the OH band. The monthly average residuals of temperature after the subtraction of the mean seasonal variation were used for a search for the solar component of temperature response. The dependence of temperatures on solar activity has been investigated using the Ottawa 10.7 cm flux as a proxy. A linear regression fitting on residual temperatures yields a solar cycle coefficient of 4.24 ± 1.39 K/100 solar flux units (SFU). The cross-correlation analyses showed that changes of the residual temperature follow changes of solar activity with a quasi-two year delay (25 months). The temperature response at the delay of 25 months reaches 7 K/100 SFU. The possible reason of the observed delay can be an influence of quasi-biennial oscillations (QBO) of the atmosphere on the relation of temperature and solar activity. The value of the temperature trend after the subtraction of seasonal and solar components is not statistically significant.     

2D and 3D MHD simulations of disk accretion by rotating magnetized stars: Search for variability

We performed 2D and full 3D magnetohydrodynamic simulations of disk accretion to a rotating star with an aligned or misaligned dipole magnetic field. We investigated the rotational equilibrium state and derived from simulations the ratio between two main frequencies: the spin frequency of the star and the orbital frequency at the inner radius of the disk. In 3D simulations we observed different features related to the non-axisymmetry of the magnetospheric flow. These features may be responsible for high-frequency quasi-periodic oscillations (QPOs). Variability at much lower frequencies may be connected with restructuring of the magnetic flux threading the inner regions of the disk. Such variability is specifically strong at the propeller stage of evolution.