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Solar magnetic feature detection and tracking for space weather monitoring
Bloomfield, D. S.; Gallagher, P. T.; McAteer, R. T. J. +1 more
We present an automated system for detecting, tracking, and cataloging emerging active regions throughout their evolution and decay using SOHO Michelson Doppler Interferometer (MDI) magnetograms. The SolarMonitor Active Region Tracking (SMART) algorithm relies on consecutive image differencing to remove both quiet-Sun and transient magnetic featur…
Ion- and electron-acoustic solitons and double layers in multi-component space plasmas
Lakhina, G. S.; Singh, S. V.; Kakad, A. P.
A general model for the ion- and electron-acoustic solitons and double layers in a multi-component unmagnetized plasma consisting of background electrons, counter-streaming electron beams and ions is discussed. The model is based on the multi-fluid equations and the Poisson equation, and uses the Sagdeev pseudo-potential techniques. For identical …
Time-dependent cosmic ray modulation
Ferreira, S. E. S.; Potgieter, M. S.; Engelbrecht, N. E. +2 more
Time-dependent cosmic ray modulation is calculated over multiple solar cycles using our well established two-dimensional time-dependent modulation model. Results are compared to Voyager 1, Ulysses and IMP cosmic ray observations to establish compatibility. A time-dependence in the diffusion and drift coefficients, implicitly contained in recent ex…
An overview of RADOM results for earth and moon radiation environment on Chandrayaan-1 satellite
Girish, V.; Vadawale, S. V.; Goswami, J. N. +5 more
The RADiatiOn Monitor (RADOM) is a miniature dosimeter-spectrometer that flew onboard the Chandrayaan-1 lunar mission in order to monitor the local radiation environment. Primary objective of the RADOM experiment was to measure the total absorbed dose, flux of surrounding energetic particles and spectrum of the deposited energy from high energy pa…
Coronal mass ejection detection using wavelets, curvelets and ridgelets: Applications for space weather monitoring
Gallagher, P. T.; Young, C. A.; McAteer, R. T. J. +1 more
Coronal mass ejections (CMEs) are large-scale eruptions of plasma and magnetic field that can produce adverse space weather at Earth and other locations in the Heliosphere. Due to the intrinsic multiscale nature of features in coronagraph images, wavelet and multiscale image processing techniques are well suited to enhancing the visibility of CMEs…
Actors of the main activity in large complex centres during the 23 solar cycle maximum
Mandrini, C. H.; Schmieder, B.; Molodij, G. +10 more
During the maximum of Solar Cycle 23, large active regions had a long life, spanning several solar rotations, and produced large numbers of X-class flares and CMEs, some of them associated to magnetic clouds (MCs). This is the case for the Halloween active regions in 2003. The most geoeffective MC of the cycle (Dst = -457) had its source during th…
Simulation of cometary jets in interaction with the solar wind
Glassmeier, K. -H.; Koenders, C.; Motschmann, U. +3 more
The influence of cometary jets on the solar wind interaction is studied with a 3D hybrid simulation. Anisotropic outgassing patterns were until recently not considered in cometary simulations, despite strong anisotropies found at observations. Comet 67P Churyumov-Gerasimenko, the target of the ROSETTA mission, was chosen as a case study for a simu…
Unusually strong magnetic fields in Titan's ionosphere: T42 case study
Coates, A. J.; Russell, C. T.; Wei, H. Y. +7 more
Observations of unusually large magnetic fields in the ionosphere indicate periods of maximum stress on Titan's ionosphere and potentially of the strongest loss rates of ionospheric plasma. During Titan flyby T42, the observed magnetic field attained a maximum value of 37 nT between an altitude of 1200 and 1600 km, about 20 nT stronger than on any…
Kink-like mode of a double gradient instability in a compressible plasma current sheet
Korovinskiy, D. B.; Semenov, V. S.; Erkaev, N. V. +4 more
A linear MHD instability of the electric current sheet, characterized by a small normal magnetic field component, varying along the sheet, is investigated. The tangential magnetic field component is modeled by a hyperbolic function, describing Harris-like variations of the field across the sheet. For this problem, which is formulated in a 3D domai…
Background and pickup ion velocity distribution dynamics in Titan's plasma environment: 3D hybrid simulation and comparison with CAPS T9 observations
Hartle, R. E.; Sittler, E. C.; Cooper, J. F. +2 more
In this report we discuss the ion velocity distribution dynamics from the 3D hybrid simulation. In our model the background, pickup, and ionospheric ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. We also tak…