Abstract Details
| Name: Rohit Chhiber Affiliation: NASA Goddard Space Flight Center and University of Delaware Conference ID: ASI2024_299 Title : On the properties of the Alfven transition zone separating the solar corona and the solar wind Authors and Co-Authors : Rohit Chhiber1,2, William Matthaeus2, Arcadi Usmanov1,2, Steven Cranmer3, Melvyn Goldstein4, Riddhi Bandyopadhyay5, Francesco Pecora2 Abstract Type : Poster Abstract Category : Sun, Solar System, Exoplanets, and Astrobiology Abstract : A global magnetohydrodynamic model of the solar wind with turbulence transport and Parker Solar Probe (PSP) observations are used to investigate properties of the critical transition between sub-Alfvenic flow and super-Alfvenic flow in the solar atmosphere. Ubiquitous turbulent fluctuations in this region imply that the transition takes place in fragmented subvolumes within a general "Alfven zone" that extends over several solar radii. Model estimates of the probability of Alfvenic transitions as a function of heliocentric distance (r) are compared with PSP observations, finding remarkable agreement. Maps are made of the characteristic size and duration of subAlfvenic blobs/intervals as a function of r and heliolatitude. The flow of Alfvenic signals in this zone is investigated, indicating the possibility of a prolonged period of stochastic motion wherein signals are trapped between subAlfvenic and superAlfvenic states before eventually flowing towards or away from the Sun. PSP observations are used to compare turbulence properties of subAlfvenic and superAlfvenic solar wind within the Alfven zone. |