Search Publications
Automated crater detection algorithms from a machine learning perspective in the convolutional neural network era
DeLatte, D. M.; Crites, S. T.; Guttenberg, N. +1 more
Convolutional Neural Networks (CNN) offer promising opportunities to automatically glean scientifically relevant information directly from annotated images, without needing to handcraft features for detection. Crater counting started with hand counting hundreds, thousands, or even millions of craters in order to determine the age of geological uni…
Numerical integration of stochastic differential equations: A parallel cosmic ray modulation implementation on Africa's fastest computer
Moeketsi, D. M.; Engelbrecht, N. E.; Strauss, R. D. +2 more
Three-dimensional studies of the transport and modulation of cosmic ray particles in turbulent astrospheres require large-scale simulations using specialized scientific codes. Essentially, a multi-dimensional Fokker-Planck type equation (a parabolic diffusion equation) must be integrated numerically. One such approach is to convert the relevant tr…
First solar observations with ALMA
Loukitcheva, Maria
The Atacama Large Millimeter-Submillimeter Array (ALMA) has opened a new window for studying the Sun via high-resolution high-sensitivity imaging at millimeter wavelengths. In this contribution I review the capabilities of the instrument for solar observing and describe the extensive effort taken to bring the possibility of solar observing with AL…
LISA Pathfinder mission extension: A feasibility analysis
Rasotto, Mirco; Renk, Florian; Dei Tos, Diogene A. +1 more
A proposed mission extension for LISA Pathfinder involved redirecting the probe to the Sun-Earth gravitational saddle point. Realistic models for both space and ground segments were used to carry out a number of analyses for trajectory design, orbit determination, and navigation cost. In this work, we present the methods that allow assessing the f…
The dynamic chromosphere: Pushing the boundaries of observations and models
Pereira, Tiago M. D.
The interface between the bright solar surface and the million-degree corona continues to hold the key to many unsolved problems in solar physics. Advances in instrumentation now allow us to observe the dynamic structures of the solar chromosphere down to less than 0.″1 with cadences of just a few seconds and in multiple pola…
Solar irradiance, climatic indicators and climate change - An empirical analysis
Singh, A. K.; Bhargawa, Asheesh
Since the Sun is the main source of energy for our planet therefore even a slight change in its output energy can make a huge difference in the climatic conditions of the terrestrial environment. The rate of energy coming from the Sun (solar irradiance) might affect our climate directly by changing the rate of solar heating of the Earth and the at…
Data-driven modelling of the Van Allen Belts: The 5DRBM model for trapped electrons
Kretschmar, Peter; Ness, Jan-Uwe; Kuulkers, Erik +10 more
The magnetosphere sustained by the rotation of the Earth's liquid iron core traps charged particles, mostly electrons and protons, into structures referred to as the Van Allen Belts. These radiation belts, in which the density of charged energetic particles can be very destructive for sensitive instrumentation, have to be crossed on every orbit of…
Potential role of energetic particle observations in geomagnetic storm forecasting
Valtonen, Eino; Ameri, Dheyaa
We have searched for solar proton events consisting of both solar energetic particles (SEPs) accelerated near the Sun and energetic storm particles (ESPs) accelerated by interplanetary shocks driven by coronal mass ejections (CMEs) and observed near the time when the shock passes the observer. The purpose of this study is to investigate the possib…
Variation of coronal holes latitudinal distribution: Correction of limb brightening of EUV coronal images
Chargeishvili, B. B.; Maghradze, D. A.; Japaridze, D. R. +4 more
We studied the limb brightening of SOHO EIT daily images of the solar corona taken in 195 Å wavelength line from 1996 to 2018. Using special software, we studied the distribution of the background intensity of the entire disk in the direction of rotation (horizontally) and perpendicular to the direction of rotation (vertical). The study shows that…
A statistical study of CME-associated flare during the solar cycle 24
Beheary, M. M.; Shaltout, Abdelrazek M. K.; Amin, Eid A. +1 more
We investigate on the relationship between flares and coronal mass ejections (CMEs) in which a flare started before and after the CME events which differ in their physical properties, indicating potentially different initiation mechanisms. The physical properties of two types flare-correlated CME remain an interesting and important question in spa…