The best aurora display of the Spring season 2021!
Amazing night of auroras with all kinds of random happenings...
It was 16th of April 2021. I was watching Estonian aurora site virmalised for aurora forecast. I noticed that aurora indicators were improving, bz -value was negative as it is supposed to be (negative value means better chance to auroras in Southern Finland) and also proton density was pretty good (in terms of our relatively southern location). Only the speed of solar wind was not as good as I hoped it to be, but things were changing all the time. The best display was supposed to happen the next night, but the aurora indicators were compelling and that's why I kept on gazing at them all the time. My plan for the night was to photograph calm aurora arc in the sleepy and idyllic village of Untamala here in Laitila municipality.
So I was anticipating the night.
While I was waiting and doing some chores, I was watching the real time all sky camera of Porin Karhunvartijat in Ulvila, near Pori city, about 62 km north from Laitila. The afterglow of a sunset was strong and it was lasting forever. There was some cirrus clouds in the camera. I opened the satellite image of FMI (Finnish Meteorological Institute) by the all sky camera and I noticed some thin cirrus- and cirrostratus veil north of Pori. I continued with my chores and kept on watching the all sky camera. Then I was thinking about it again, and I had to watch the satellite image again. There were some high cloud veils north from Pori, by they were very far away. It's not possible, that they are so clearly visible in the camera. I was thinking about it, when I realized that the cloud is getting bigger and the sky was still very light. When I was looking the satellite image, it was clear to me that the clouds were not moving. Oh my God, I had no other choice than go outside and see for myself what is going on. I shouted to my husband that I would go out quickly. I walked by the road near our house and noticed that there was an aurora arc behind the forest, that was getting pulsating and getting brighter for a while.
Immediately I walked back and shouted to my husband, that now we need to go urgently, how quickly can you prepare yourself to go? We are about to go now, and while we were going, I was explaining my husband what it all was about. Then finally we were driving towards Untamala by bumpy gravel roads. It didn't take too long until we arrived at the observing site. Then I parked my car and we quickly ran to the nearby field to take some photos.
Besides auroras, also the Moon was in the sky. I took some photos towards the Moon, and we thought that we were seeing some arc-like form in the photos. I was remembering that in year 2017 there was a similar aurora display with low-hanging rays under aurora arc just like now. The display was progressing in similar manner, and I was expecting SAR to appear. I was gazing the sky for SAR and taking lots of photos to see if it appeared in the photos. When looking at the photos at the display of the camera, I could only see some cirrus clouds. Meanwhile the aurora display had activated and I had to start shooting seriously. (Later when processing the photos at my computer, I noticed that there really was SAR and it had been recorded with first three test shots!)
An unforgettable three hour episode followed. We observed pulsating aurora patches and tall rays, that were blue in the top and faded from violet to pink. We also observed a duplicated aurora belt in the northern sky. There were some lilac and pink rays that soon disappeared as the belt become brighter. In the very end of the display two bright aurora rays appeared in the sky, that were slowly and majestically drifting along the sky. At this moment we packed our stuff in the car and watched the display to fade away. It was about 3 AM when we started the engine of our car to drive back home. It was good to stay awake, what an amazing way to end the aurora season! (even though we were ending the season still three times after this night...)
I said to my husband, that I can promise that when you go out with me, the sessions easily stretch to the morning hours, and that if there is any headache or tiredness, it is only caused by sleep deprivation :P