STORM - Solar system plasma Turbulence:  Observations, inteRmittency and Multifractals

Science Objectives

The main objective of the project is to make a systematic investigation of the in-situ space plasma data bases collected by ESA's missions launched in the solar system, Giotto, Ulysses, Rosetta, Cluster and Venus Express together with other satellite data bases, in particular NASA's Cassini, Mars Global Surveyor and THEMIS. We use these data bases to perform a systematic analysis of electromagnetic and plasma fluctuations in order to find evidence of turbulence and intermittency. Our approach is meant to reveal new universal properties of intermittent and anisotropic turbulence and multifractals in solar system plasmas (solar wind; the planetary foreshock and magnetosheath, both for the quasi-parallel and quasi-perpendicular geometry, the terrestrial magnetospheric cusps, the Low Latitude Boundary Layers of magnetized planets) and how these properties vary within the solar cycle and with the distance from the Sun.


Operational objectives

The specific science objectives outlined above are structured into several strategic and operational objectives, adapted to the specific conditions of the 5th FP7 Space Call. The operational objectives listed below are attached to work-packages and deliverables.

  1. To investigate the topology of the turbulent energy transfer and dissipation in solar system plasmas and to understand its variability in the heliosphere, where is sampled by ESA's Giotto, Venus Express, Cluster, Rosetta and NASA's THEMIS, Cassini and Mars Global Surveyor and at higher heliospheric latitudes (Ulysses).
  2. To determine a relevant set of quantitative parameters for the description of the nonlinear state of the solar wind and planetary plasma environment. (e.g. PSD spectral exponent, statistical moments of incremental time-series in terms of scale parameter, structure function scaling exponent curve). To elaborate a method for the estimation of the uncertainties.
  3. To evaluate the solar cycle effects on the intermittency of the turbulent transfer of energy in the solar wind and planetary plasmas.
  4. To extract the multifractal properties of turbulent fluctuations in the solar wind and planetary magnetospheres using the partition function and the rank ordered (ROMA) approach; to compare the results of the two methods and better understand ROMA.
  5. To explore the effect of space weather events and to investigate the scaling and multifractal properties of the fluctuations of the geomagnetic indices at solar maximum versus solar minimum and to search for similarities and differences with scaling and multifractal properties of the solar wind.
  6. To use existing data bases as a test bed for investigating possible connections between multifractals and the concept of Forced and/or Self Organized Criticality (FSOC) and to extract the SFOC parameters at solar minimum and solar maximum, in the solar wind and planetary plasma environment.
  7. To-evaluate the anisotropy of turbulence in key magnetospheric regions (magnetosheath, magnetic cusps, boundary layers)and in the solar wind (at 1 AU), at solar maximum and minimum, using multi-spacecraft methods.
  8. To compile data bases including the nonlinear parameters determined for different regions of the solar wind and planetary magnetospheres system visited by the space missions as well as for terrestrial observations in terms of geomagnetic latitudes extended to global geomagnetic indices (AE, Dst, SYMH).
  9. To create an integrated software library to include the full set of analysis methods devoted to the analysis of turbulence properties from time series provide by satellites.