| 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 : | Rohit Chhiber1,2, William Matthaeus2, Arcadi Usmanov1,2, Steven Cranmer3, Melvyn Goldstein4, Riddhi Bandyopadhyay5, Francesco Pecora2 |
| Authors Affiliation: | 1 Rohit Chhiber, Arcadi Usmanov NASA Goddard Space Flight Center, Greenbelt-20771, USA
2 Rohit Chhiber, William Matthaeus, Arcadi Usmanov, Francesco Pecora University of Delaware, Newark-19716, USA
3 Steven Cranmer University of Colorado, Boulder-80309, USA
3 Melvyn Goldstein Space Science Institute, Boulder-80301, USA
4 Riddhi Bandyopadhyay Princeton University, Princeton-08544, USA |
| Mode of Presentation: | 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. |
