Search Publications
Large-scale waves in the solar corona: The continuing debate
Warmuth, Alexander
Ten years after the first observation of large-scale wave-like coronal disturbances with the EIT instrument aboard SOHO, the most crucial questions concerning these “EIT waves” are still being debated controversially - what is their actual physical nature, and how are they launched? Possible explanations include MHD waves or shocks, launched by fl…
Turbulence, complexity, and solar flares
Gallagher, Peter T.; McAteer, R. T. James; Conlon, Paul A.
The issue of predicting solar flares is one of the most fundamental in physics, addressing issues of plasma physics, high-energy physics, and modelling of complex systems. It also poses societal consequences, with our ever-increasing need for accurate space weather forecasts. Solar flares arise naturally as a competition between an input (flux eme…
Characterization of the slow wind in the outer corona
Antonucci, Ester; Riley, Pete; Linker, Jon A. +3 more
The study concerns the streamer belt observed at high spectral resolution during the minimum of solar cycle 23 with the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO. On the basis of a spectroscopic analysis of the O VI doublet, the solar wind plasma parameters are inferred in the extended corona. The analysis accounts for the coronal m…
Prediction of uncertainties in atmospheric properties measured by radio occultation experiments
Withers, Paul
Refraction due to gradients in ionospheric electron density, Ne, and neutral number density, nn, can shift the frequency of radio signals propagating through a planetary atmosphere. Radio occultation experiments measure time series of these frequency shifts, from which Ne and nn can be determined. Major …
The Planetary Laboratory for Image Analysis (PLIA)
Sánchez-Lavega, A.; Rojas, J. F.; Pérez-Hoyos, S. +4 more
The observation, characterization, and understanding of planetary atmospheres are key components of Solar System exploration. Their study requires, among other observations, the use of image data acquired from spacecrafts. The basic tasks that are generally used to work with planetary image data are: image navigation, projection, image processing,…
The distributions of the OH Meinel and O(a1Δ-X3Σ) nightglow emissions in the Venus mesosphere based on VIRTIS observations
Drossart, P.; Piccioni, G.; Gérard, J. -C. +2 more
O(aΔ) and recently discovered OH Meinel nightglow emissions have been observed at the limb with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS-M) instrument on board the Venus Express satellite. Hydroxyl bands belonging to Δv=1 sequence between 2.60and3.14µm and to Δv=2 sequence at 1.40-1.46µm have been unambiguously ide…
Kinetic study of a N2-CH4 afterglow plasma for production of N-containing hydrocarbon species of Titan’s atmosphere
Pintassilgo, C. D.; Loureiro, J.
We present the results from a self-consistent kinetic model simulating the afterglow of a flowing microwave discharge in pure N 2 in which CH 4 is introduced in the post-discharge. The simulation is carried out for a discharge operating at 433 MHz, in a tube of 1.9 cm inner radius, at the pressure range 26.6-133 Pa. In the po…
Total solar irradiance absolute level from DIARAD/SOVIM on the International Space Station
Mekaoui, Sabri; Dewitte, Steven; Conscience, Christian +1 more
Current measurements from DIARAD/VIRGO, PMO6V/VIRGO and ACRIM3 radiometers are of the same order of magnitude, but differ from TIM/SORCE by about 4.5 W m -2. This difference is higher than the sum of the claimed individual absolute uncertainties of the instruments. In this context, the SOLAR payload on the International Space Station em…
Solar wind origins in coronal holes and in the quiet Sun
Tu, C. -Y.; Marsch, E.; Tian, H. +1 more
Coronal hole (CH) and the quiet Sun (QS) are considered to account for sources of fast and slow solar wind streams, respectively. The differences between the solar wind streams flowing out from the CH and the QS are thought to be related with different plasma generation and acceleration mechanisms in the respective source regions. Here we review r…
Study of hot flow anomalies using Cluster multi-spacecraft measurements
Dandouras, I.; Daly, P. W.; Lucek, E. A. +2 more
Hot flow anomalies (HFAs) were first discovered in the early 1980s at the bow shock of the Earth. In the 1990s these features were studied, observed and simulated very intensively and many new missions (Cluster, THEMIS, Cassini and Venus Express) focused the attention to this phenomenon again. Many basic features and the HFA formation mechanism we…