Conveners
Space Science
- Zama Thobeka Katamzi-Joseph (South African National Space Agency)
Space Science: Space Science
- Zama Thobeka Katamzi-Joseph (South African National Space Agency)
Space Science
- Zama Thobeka Katamzi-Joseph (South African National Space Agency)
Space Science
- Zama Thobeka Katamzi-Joseph (South African National Space Agency)
Space Science
- There are no conveners in this block
Space Science
- Zama Thobeka Katamzi-Joseph (South African National Space Agency)
Space Science
- There are no conveners in this block
Space Science
- Zama Thobeka Katamzi-Joseph (South African National Space Agency)
Mr
Carel Pieter Wolmarans
(North-West University)
09/07/2019, 10:00
Track D2 - Space Science
Oral Presentation
Solar cycle 20, in the mid 1960s, was very unusual in that the usual cosmic ray intensity decline towards solar maximum was not accompanied by an increase in heliospheric magnetic field magnitude as seen in subsequent solar cycles. This presents something of a quandary where cosmic ray modulation studies are concerned. This study presents a novel investigation of historic magnetic field...
Dr
G. J. J. Botha
(Northumbria University, UK)
09/07/2019, 10:20
Track D2 - Space Science
Oral Presentation
2D reconnection is studied numerically in the context of various atmospheric layers in the Sun: the fully ionized coronal plasma; the partially ionized chromospheric plasma; the almost-neutral photospheric plasma. Numerical simulations solve the compressible, resistive magnetohydrodynamic equations, with reconnection triggered by driving external flows perpendicularly towards an equilibrium...
Dr
G. J. J. Botha
(Northumbria University)
09/07/2019, 10:40
Track D2 - Space Science
Oral Presentation
A 3D non-eruptive kink-unstable coronal flux rope is simulated by solving numerically the nonlinear magnetohydrodynamic equations with parallel thermal conduction. The time evolution from the initial unstable equilibrium is forward modelled by generating synthetic spectral intensity maps as observed by DKIST/DL-NIRSP and Hinode/EIS using the CHIANTI database. The predicted signatures of the...
Mr
Clinton Clinton Denis Stevens
(North-West University (Potchefstroom))
09/07/2019, 11:20
Track D2 - Space Science
Oral Presentation
Solar phenomena such as solar prominences, -flares and -coronal mass ejections (collectively known as solar variations) directly influence our way of life on Earth by impacting its atmosphere, climate and magnetic field. Furthermore the success of all scientific endeavours within the solar system and the prospects of space travel are significantly impacted by space weather. It is therefore...
Mr
Jabus van den Berg
(North West University)
09/07/2019, 11:40
Track D2 - Space Science
Oral Presentation
The focused transport of solar energetic particles has received increasingly more interest in the last couple of years due to upcoming missions to the Sun. Stochastic differential equations offer a numerically robust way to model solar energetic particle events, but very few models exist which utilize the full capability of this approach. A step is taken towards this goal by solving the...
Mr
KATLEGO MOLOTO
(NORTH WEST UNIVERSITY)
09/07/2019, 12:00
Track D2 - Space Science
Oral Presentation
A simplified ab initio approach is followed to model cosmic-ray (CR) modulation from first principles, using a novel time-dependent three-dimensional stochastic solver of the Parker transport equation, taking into account the various processes that modulate the intensities of these cosmic rays on their way to the inner heliosphere, and thus to Earth. This approach focuses on the effects of...
Ms
Nadine Dempers
(North-West University)
09/07/2019, 12:20
Track D2 - Space Science
Oral Presentation
The perpendicular diffusion coefficient (DC) plays a crucial role in the transport of low-energy cosmic ray electrons, which include a proportion of solar energetic particles, electrons originating in the Jovian magnetosphere, and electrons of galactic origin. In turn, various properties of heliospheric magnetic field turbulence have a strong influence on perpendicular DC expressions derived...
Dr
Mabedle Ngobeni
(North West University)
09/07/2019, 12:40
Track D2 - Space Science
Oral Presentation
A comprehensive three-dimensional numerical drift model is used to compute the modulation of cosmic ray protons and anti-protons in the heliosphere. This is done using the latest development in diffusion coefficients and cosmic ray interstellar spectra. Emphasis is placed on the effects of the spatial and rigidity dependence of the scattering parameter (ωτ), with ω the gyro-frequency and τ a...
Dr
Du Toit Strauss
(Centre for Space Research, North-West University)
10/07/2019, 11:20
Track D2 - Space Science
Oral Presentation
We live in an interesting time of space exploration; NASA is planning to return to the moon in 2024 and a permanently crewed lunar outpost also in the pipeline. This is part of a renewed drive to land the first humans on Mars in the 2030's. Private companies, such as SpaceX, also have such plans in place. A major obstacle to long-term crewed missions outside the protective shielding provided...
Dr
Shimul Maharaj
(South African National Space Agency (SANSA) Space Science)
10/07/2019, 11:40
Track D2 - Space Science
Oral Presentation
The existence of stopbands, which are ranges in speed where solitons
cannot propagate was proposed for the very first time in a study of fast ion-acoustic solitons by Nsengiyumva et al. [1] for a plasma composed of cold ions, warm (adiabatic) ions and Boltzmann electrons. We recall that the stopbands arise when the warm ion limiting curve is double-valued in speed over a range of...
Dr
Shimul Maharaj
(South African National Space Agency (SANSA) Space Science)
10/07/2019, 12:00
Track D2 - Space Science
Oral Presentation
The effects of the inclusion of finite drift speed for the warm ions on fast ion-acoustic soliton stopbands is theoretically investigated
in a plasma which is composed of cold ions, warm (adiabatic) ions and Boltzmann electrons. The stopbands are intermediate ranges in speed for which solitons cannot propagate, yet soliton propagation is still possible for lower and higher speeds. For warm...
Dr
Zama Thobeka Katamzi-Joseph
(South African National Space Agency)
10/07/2019, 14:00
Track D2 - Space Science
Mr
Njabulo Mbanjwa
(UKZN)
11/07/2019, 11:20
Track D2 - Space Science
Oral Presentation
Pc5 pulsations are global magneto-hydrodynamic events in the magnetosphere. We investigate quiet-time Pc5 pulsation events and their likely excitation mechanisms using SuperDARN, and Omni and GOES satellite data. With the interplanetary magnetic field (IMF) Bz northward, we investigate cases where the IMF By component is positive and negative. We investigate the excitation mechanism of the...
Dr
John Bosco Habarulema
(South African National Space Agency)
11/07/2019, 11:40
Track D2 - Space Science
Oral Presentation
An analysis of the counter-electrojet occurrence (CEJ) during 2008-2014 is presented for the African and American sectors based on local daytime (0700-1700 LT) observations from the Communications and Navigation Outage Forecasting System (C/NOFS) vertical ion plasma drift (equivalent to vertical E × B at altitude of about 400 km) and ground-based magnetometers. Using quiet time (Kp≤3) data,...
Dr
Zama Thobeka Katamzi-Joseph
(South African National Space Agency)
11/07/2019, 12:00
Track D2 - Space Science
Oral Presentation
Atmospheric gravity waves (AGWs) were observed over South Africa during the recovery phases of coronal mass ejection (CME) and corotating interaction region (CIR) driven storms on 3 Aug 2016 and 31 Jan 2017 respectively. The characteristics of the AGWs are determined from observations of intensity of the 630 nm airglow images, global positioning systems (GPS) total electron content (TEC) and...
Dr
Zama Thobeka Katamzi-Joseph
(South African National Space Agency)
11/07/2019, 12:20
Track D2 - Space Science
Oral Presentation
Observations of large-scale atmospheric gravity waves/traveling ionospheric disturbances (AGWs/TIDs) from measurements of
Global Positioning System (GPS) total electron content (TEC) and Fabry–Perot Interferometer’s (FPI’s) intensity of oxygen red line
emission at 630 nm measurements over Svalbard on the night of 6 January 2014 are reported here. TEC large-scale TIDs have primary periods...
