From the Sun’s atmosphere to the Earth’s atmosphere: an overview of scientific models available for space weather developments

Abstract

Abstract. Space weather aims at setting operational numerical tools in order to nowcast, forecast and quantify the solar activity events, the magnetosphere, ionosphere and thermosphere responses and the consequences on our technological societies. These tools can be divided in two parts. The first has a geophysical base (Sun, interplanetary medium, magnetosphere, atmosphere). The second concerns technological applications (telecommunications, spacecraft orbits, power plants ...). In this paper, we aim at giving an overview of the models that belong to the first class (geophysics) that might serve in the future as a basis for building global operational codes. For each model, we consider the physics underneath, the input and output parameters, and whether it is already operational, whether it may become operational in the near future, or if it is an academic research tool. Relevant references are given in order to serve as a starting point for further readings.

Solar Weather Event Modelling and Prediction

“…Here we concentrate on the solar irradiance in the ultraviolet range as one of the key parameters for space weather (Lathuillère et al 2002) for which still very few continuous and spectrally resolved measurements exist. The irradiance must be measured from space but present detectors suffer from degradation and do not allow one to make long-term measurements.…”

“…: -a proof of chaoticity based on the neutrino emission (Mandal and Raychaudhuri 2005); -the simulation of chaotically modulated stellar dynamos (Tobias et al 1995); -the evidence of a chaotic behaviour in the solar dynamo from the variations of the solar magnetic field in the last 100 years (Lockwood et al 1999); -the evidence of chaoticity from the analysis of the period and phase of the 88-year solar cycle (Feynman and Gabriel 2004); -the occurrence of grand minima/maxima driven by a stochastic/chaotic process (Usoskin et al 2007); -a model of chaotic reconnection due to fast mixing of vortex-current filaments (Yatsuyanagi et al 2000); -stochastic reconnection (Lazarian et al 2004). Mundt et al (1991) studied the variability of solar activity over long time scales, given semiquantitatively by measurements of sunspot numbers R z , as a nonlinear dynamical system and found a positive Lyapunov exponent indicating that the solar activity variability described by R z can be described as a low dimension non-linear chaotic system of dimension 2.3.…”

Retrieving the solar EUV spectrum from a reduced set of spectral lines

“…Following the inconclusive efforts to continuously measure the EUV spectrum, various substitutes have been used as inputs for thermospheric/ionospheric models (Lathuillère et al, 2002). Best known are the F10.7 (radio flux at 10.7 cm) or the Mg II core-to-wing indices, both of which can be conveniently measured from ground.…”

Progress in space weather modeling in an operational environment

“…The results of the studies were published in 2001 and are available for download at http://www.esa-spaceweather.net/index.html (Watermann et al 2009a). The study conducted by the consortium led by ALCATEL Space & LPCE (France) yielded an overview of the scientific models available for space weather developments that was given by Lathuillere et al (2002). Both empirical and physical models were systematically considered in this review to conclude highlighting the necessity of more developments and improvements of empirical models as a key driver of the development of operational space weather models and consequently, the necessity of routine availability of relevant direct measurements or scientifically agreed proxies.…”

“…Space weather can be considered from two different stand points, the numerical modeling of the whole system on one hand, and the needs of the users, i.e., monitoring and forecasting the values of specific quantities, on the other hand (Lathuillere et al 2002). One may argue that the two views are met collaboratively for the development of operational products and tools for space weather prediction purposes, which is a strong requirement for the reliable performance of several applications affected by space weather under all possible conditions.…”