BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-8186 DTSTART:20230206T180000Z DURATION:PT1H0M0S DTSTAMP:20260414T054752Z LAST-MODIFIED:20230202T155833Z LOCATION:2241 Chamberlin Hall SUMMARY:The Eulerian space-time correlation of magnetohydrodynamic tur bulence and the analysis of Parker Solar Probe measurements\, Plasma P hysics (Physics/ECE/NE 922) Seminar\, Jean Carlos Perez\, Florida Inst itute of Technology DESCRIPTION:Understanding the Eulerian space-time correlation of magne tohydrodynamic (MHD) turbulence\, as well as its possible universal pr operties\, is of critical importance in the analysis and interpretatio n of solar wind measurements when the Taylor hypothesis is not valid. This so-called frozen-in-flow hypothesis posits that the temporal vari ation of spacecraft signals is solely due to the spatial variation of a frozen structure passing by the observation point\, in which case th e turbulence dynamics can essentially be considered to be frozen in th e plasma frame. The Parker Solar Probe (PSP) mission\, launched in 201 8\, is presently probing the near-Sun solar wind with an orbit that wi ll reach its point of closest approach next year at a heliospheric rad ius of approximately 0.045 au\, which is seven times closer than any p revious mission. During each close encounter with the Sun\, the assump tions supporting TH are expected to break down. In this talk\, I will discuss a recent semi-phenomenological model of the Eulerian two-time two-point (space-time) correlation for incompressible MHD turbulence and its impact on the interpretation of PSP data. Using this model we introduce a methodology that allows one to reconstruct the reduced ene rgy spectrum of magnetic fluctuations vs spatial wavenumber from the f requency spectrum of fluctuations measured by PSP near the Alfven crit ical point\, where TH is expected to break down.  
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\n URL:https://www.physics.wisc.edu/events/?id=8186 END:VEVENT END:VCALENDAR