10:02:09 From Ian Cohen (he/him) : Good morning everyone, welcome to Day 2! 10:02:35 From Ian Cohen (he/him) : Reminder, we do have a dedicated Slack workspace as well: https://join.slack.com/t/mmsspring2021-mbv5597/shared_invite/zt-nnwo71ra-0o2fx6xtDmLgIkhNyVdgVQ 10:04:53 From Lynn Wilson : What is the air speed velocity of an unladen swallow? 10:05:13 From Frederick Wilder : Lynn - African or European? 10:05:36 From Jason S : “about 24 miles per hour” 10:05:55 From Dominic Payne : I don't know that! 10:06:09 From Andy : We don’t use miles around these parts. 10:06:58 From Lynn Wilson : HA 10:10:09 From Thom Moore : Isn’t Slack for slack time? 10:37:05 From Lynn Wilson : Anomalous cyclotron: instead of electrons anti-parallel propagating against whistler, extra fast electrons over take the whistler propagating in the same direction 10:38:36 From Frederick Wilder : Thanks Lynn - from the papers I was reading on it, it was hard to get a physical picture from the math, unlike normal cyclotron resonance and landau resonance 10:40:01 From Lynn Wilson : In normal cyclotron resonance, the two propagate anti-parallel and in the particle's guiding center rest frame, the wave's Doppler-shifted frequency matches the particle's gyrofrequency 10:40:50 From Frederick Wilder : Yeah - the normal is pretty textbook (as in you can find cartoons in textbooks!) :) 10:40:51 From Lynn Wilson : In anomalous, they propagate in the same direction which usually requires extremely high energy electrons to over take and reverse the whistler polarization in the electron's guiding center rest frame so it matches the electron's gyrofrequency and polarization 10:41:53 From Frederick Wilder : So if the waves remain right-handed, it would have to be landau resonance then 10:42:42 From Lynn Wilson : Wait, sorry 10:42:59 From Lynn Wilson : An ion would have to overtake the whistler to reverse the polarization 10:42:59 From Richard Denton To Ian Cohen (he/him)(privately) : Can you mute the noisy people? 10:43:08 From Lynn Wilson : sorry, got the signs mixed up [facepalm] 10:43:35 From Lynn Wilson : The electron won't need to change the polarization since it will still want the wave to be RH 10:44:12 From Ian Cohen (he/him) To Richard Denton(privately) : I don’t see any live mics Richard, but I’ll keep an eye open 10:44:45 From Ian Cohen (he/him) To Shan Wang(privately) : Hi Shan, I think there was a bit of background noise coming from your mic. Please unmute yourself when you’re ready to talk. Thanks! 10:44:49 From Robert Strangeway : Lynn is correct that for anomalous gyro-resonance the electron Doppler-shifts the wave to - gyro-frequency, that is left-handed in the electron frame. There is still a resonant interaction, but likely to be less efficient (weaker growth rates). 10:45:21 From Frederick Wilder : Which is why it’s typically ignored, correct? 10:46:04 From Robert Strangeway : I think so. 11:01:22 From William Matthaeus : I think that the anomalous resonance can produce efficient damping of the associated waves, at least in some cases. Some years ago (and maybe now too) anomalous cyclotron resonant absorption was/is considered a contributor to coronal heating. 11:10:47 From Lynn Wilson : @Bill - For really high energy particles, which the corona is full of, correct? 11:23:55 From William Matthaeus : @Lynn - *higher* energy, yes. For dissipation of Alfven waves in the corona, if I recall correctly the particle's speed needs to be a few -- maybe three -- Alfven speeds. I can look that up if you are interested. I think the papers are by Marty Lee and Phil Isenberg 11:25:25 From Lynn Wilson : For electrons, I assume it's quite high energy since it would need to reverse the polarization, right? 11:32:34 From Dominic Payne : Does this have to do with large variations in the local electron energy density in the EDR due to low densities? 11:43:07 From Robert Strangeway : Is it correct to assume that “MHD cascade” is equivalent to ion-driven cascade, an “Hall cascade is electron-driven? 11:45:29 From Vic Coffey : Thank you for presenting this concept to this session! 11:46:31 From William Matthaeus : @Bob S. - roughly speaking -- yes 11:49:10 From William Matthaeus : @Lynn -- I am not certain about electron energies required for polarization reversal. My intuition is that the particle must overtake the wave by some margin (as you suggested in the thread above). So how much energy is needed should depend on the wave propagation speed. 11:54:02 From Michael Shay : Answering Robert Strangeway’s question. Yes, “MHD Cascade” is equivalent to ion cascade and “Hall cascade” could be thought of as electron cascade. 11:54:19 From Michael Shay : Vic: Your welcome 11:54:38 From Michael Shay : I’ve got to run to my appointment. Have a great discussion! 11:57:06 From yuri : @Owen, can the peak in the magnetic spectrum be related to whistlers? 11:57:44 From Julia Stawarz (she/her) : ^^I was wondering if it might be something like that as well 11:58:05 From Olivier Le Contel : @Owen: the bump on B fluctuations is quite large. I am not aware of a possible spurious noise able to produce such a bump. Yet I will take a look and will let you know. 11:58:28 From Patricia Reiff : thanks! 11:58:52 From Owen Roberts : Yes I think it Is possible Yuri. I was a bit suspicious that I didn't see anything in the electric field 11:59:08 From Ian Cohen (he/him) : WE WILL RECONVENE AT 1 PM EASTERN! 11:59:34 From Owen Roberts : Thanks Olivier