Gabriel Hofstra Posted October 26, 2017 Share Posted October 26, 2017 So I looked in the archive on Tromsø all-sky-camera on the night from 13 to 14. November 2012 and found something strange. NOTE: All times are in UTC! Around 22:40 a cloud of white aurora moved slowly above the sky. After midnight UTC time some strange happened: It looks like that the aurora leaved some sort of picket fence auroras several times durig the time betwen 01:00 and to 05:00. Around 03:20 and 03:40 this appeared a lot. One can see that there were a lot of colorful auroras due to the direction of IMF and strength of Bz. Is there an scientific explenation of these events? Like how does this green picket fence auroras appear during geomagnetic storms? What creates these white auroras? Are they related to STEVE? Edit: For information about the Picket Fence auroras. I just called it picket fence auroras because they reminds me about the picket fence structures that appear with STEVE. Link to comment Share on other sites More sharing options...
Marcel de Bont Posted October 26, 2017 Share Posted October 26, 2017 I wish I was better at understanding why aurora forms the way they do but unfortunately I do not know much about this subject. My personal experience is that aurora can become incredible intense and diverse during major sub storms. I must admit that I don't remember ever seeing white patches as on the 22:40 UTC images, but I did see white during very intense displays where the green becomes saturated in some way and turns almost white. But your example doesn't look that bright. It's just white. I don't think the picket fence is related to STEVE. The times I have seen what people call STEVE today it was clearly separated from the main aurora zone and located at a lower latitude than the main aurora was. My answers are just my personal experiences. Link to comment Share on other sites More sharing options...
Martin Posted October 27, 2017 Share Posted October 27, 2017 Hi, I also experienced white aurora with my own eyes. It was in the night from 19./20. of December in 2015. There were two incoming CMEs right behind and auroral activity was very high. I was sitting near Tromsö with my camera and was waiting. Unfortunately, whole scandinavia was coverd in clouds on that night I waited the whole night, until around 5:00 UTC in the morning. Then, a hole was formed in the clouds. I saw those white rays and I was able to take some pictures. The hole in the clouds was exactly above my head. I also do not understand on which factors the aurora appearance is dependent. I have typical pictures attached. Sometimes there is an aurora with very long rays and many colors ( I think this is the "picket fence") and sometimes the (at least for me) "more normal" shape where the aurora band is much more narrow andon the down side you have the typical color bands of white and magenta (last picture). I don't think that it is just the overall activity. The pictures of the colorful auroras where taken in the same night and activity was average (like Kp 4). Link to comment Share on other sites More sharing options...
James Rowley-Hill Posted October 29, 2017 Share Posted October 29, 2017 Had white aurora here in Norfolk this year on 13th Oct...using long exposure camera shot, WHEN looking at real time vid it appeared to be the picket fence type Aurora ...taken at same time, so maybe it moves that quick it creates a white intense blur on a single image of say more than 10 secs ...??? It was a really intense geo storm as well Link to comment Share on other sites More sharing options...
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