1 / 1

Oscillatory flow braking, current wedge dynamics, auroral streamers, and Pi2 pulsations

Oscillatory flow braking, current wedge dynamics, auroral streamers, and Pi2 pulsations. E.V. Panov 1 , W. Baumjohann 1 , R . Nakamura 1 , O. Amm 2 , M.G. Kubyshkina 3 , K.-H. Glassmeier 4 , J.M . Weygand 5 , V. Angelopoulos 5 , A.A. Petrukovich 6 , V.A. Sergeev 3

taliesin-evans
Download Presentation

Oscillatory flow braking, current wedge dynamics, auroral streamers, and Pi2 pulsations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Oscillatory flow braking, current wedge dynamics,auroral streamers, and Pi2 pulsations E.V. Panov1, W. Baumjohann1, R. Nakamura1, O. Amm2, M.G. Kubyshkina3, K.-H. Glassmeier4,J.M. Weygand5, V. Angelopoulos5, A.A. Petrukovich6, V.A. Sergeev3 1IWF, Graz, 2FMl, Helsinki,3SPbGU, St. Petersburg, 5TUBS, Germany,6UCLA, Los Angeles, 6IKI, Moscow Period and damping rate of Pi2 pulsations Plasma sheet-ionosphere current wedge (CW) system Ground field-aligned current (FAC) oscillations lag by 50 seconds, i.e., by Alfvènic transit time. Damping of Pi2 pulsations occurs on the same time scales as in the plasma sheet flows. Period of Pi2 pulsations is on average half the period of the plasma sheet flows bouncing. Near-Earth plasma sheet flow oscillations Wolf et al, 2012 predicted that FAC is a sum of DC due to dipolarizationand AC due to oscillatory braking. Auroral streamers are signatures of AC CW part Flow period agrees with prediction of thin filament oscillation. Oscillation period is longer more tailward Oscillation period at XGSM =-11 RE (about 210 s) is smaller than at XGSM=-14 RE (about 260-370s) Auroral streamers are generated by the upward part of the alterna-ting current (AC). GOCE (ESA - AOES Medialab) e- Escape into loss cone at dipolarization fronts Changing background conditions lead to decrease of oscillation frequency with distance. References Panov, E. V, et al., (2013), Ionospheric response to oscillatory flow braking in the magnetotail, JGR,118, 1529–1544, doi:10.1002/jgra.50190. Panov, E. V, et al., (2013), Transient electron precipitation during oscillatory BBF braking: THEMIS observations and theoretical estimates, JGR, 118, 3065–3076, doi:10.1002/jgra.50203 Panov, E. V, et al., (2013), Oscillatory flow braking in the magneto- tail: THEMIS statistics, GRL, 40, 2505–2510, doi:10.1002/grl.50407 Electron-whistler interaction may facili-tateelectron escape into the loss cone. 1-5 keV parallel electrons are missing.

More Related