Multi-spacecraft and multi-instrument study of the solar wind in the corona and heliosphere

Speaker: Daniele Telloni, Researcher | National Institute for Astrophysics Astrophysical Observatory of Torino, Italy
Type: virtual

Abstract: The evolution of waves and turbulence in the expanding solar wind is mostly studied statistically using broad ensembles of measurements taken at different times, at different heliocentric distances, and under different solar wind and solar conditions. Standard techniques, including power spectra and structure functions, multifractal analysis, third-order scaling laws and energy transfer, Alfvénicity, wave coherence, structure identification, non-Maxwellian features of particle distribution functions, are normally used to describe the properties of the fluctuations and how they heat and energize the plasma. However, due to the intrinsic variability and inhomogeneity of the solar wind and of its solar sources, this approach cannot capture the fundamental dynamical evolution of turbulence and the related plasma heating, necessary for understanding the general physical processes and correctly modeling the heliosphere. Using specific configurations to obtain rare measurements of the same plasma parcel by two radially aligned spacecraft may allow understanding the actual evolution of waves, turbulence and heating under different conditions. Additionally, compared observation of the solar/coronal sources and in-situ properties, possible during quadratures, will help

address the origin of turbulence and its dependency on the solar structure. As a matter of fact, linking plasma kinetic properties (waves, instabilities, energy deposition) with large-scale coronal structures will represent a breakthrough to the long-standing problem of coronal heating, onset of plasma instabilities, and wave generation. This talk reviews the most recent results obtained by exploiting the joint in-situ and remote-sensing observations during the first Parker Solar Probe - Solar Orbiter radial alignments and quadratures, and in particular the radial evolution of solar wind turbulence and solar-wind connectivity with coronal sources.

Throughout the Fall Semester Space Science and CSPAR will be conducting a Colloquium. We invite both faculty and students to join us! Refreshments for the audience are served after the talk.

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