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It was cold morning, at lowest the car showed -31 C. I drove to Mustavaara but guns were not on. But at the distance about 10 km away I saw there was swarm at Kontiolahti biathlon stadium so I drove there and got this little display from lake Höytiäinen ice. The ice fog was a bit too thick and Ac was taking over the sky. Temperature at the location was around -25 C.
2010. december 4., szombat
Light pillars and submoon from Mustavaara snowguns on 29/30 November 2010
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There are two rules for success in seeing diamond dust halos. First you have to go where the diamond dust is. Second, when you think it is time to go home, you don't. On many nights I am actually going back to home two three times, but turn back and get results. There should be a rule for example for the cases when the sky turns overcast: don't go home until after you have waited minimum 1½ hours. Often ehough I have noticed how the sky has gotten soon clear again on the way home. And you never go home when the diamond dust is on the treshold. Treshold conditions may last hours but eventually the diamond dust develops. It may not be untill the early morning hours, but it develops. And even if the diamond dust is not that good, you don't go home. Change in wind direction can make dramatic changes in halos.
This night I did not have to wait for the condition to develop. The swarm was on as I arrived to the scene soon after darkfall, temperatures around -25 C. But it was not that good, only weak pillars were seen. But I waited and eventually in the morning hours got some photos in Heinävaara, where the swarm headed from Mustavaara. Nothing spectacular but the half moon submoon was really worth the wait. It was an eerie apparition, following by your side like a messenger from beyond.
There are two rules for success in seeing diamond dust halos. First you have to go where the diamond dust is. Second, when you think it is time to go home, you don't. On many nights I am actually going back to home two three times, but turn back and get results. There should be a rule for example for the cases when the sky turns overcast: don't go home until after you have waited minimum 1½ hours. Often ehough I have noticed how the sky has gotten soon clear again on the way home. And you never go home when the diamond dust is on the treshold. Treshold conditions may last hours but eventually the diamond dust develops. It may not be untill the early morning hours, but it develops. And even if the diamond dust is not that good, you don't go home. Change in wind direction can make dramatic changes in halos.
This night I did not have to wait for the condition to develop. The swarm was on as I arrived to the scene soon after darkfall, temperatures around -25 C. But it was not that good, only weak pillars were seen. But I waited and eventually in the morning hours got some photos in Heinävaara, where the swarm headed from Mustavaara. Nothing spectacular but the half moon submoon was really worth the wait. It was an eerie apparition, following by your side like a messenger from beyond.
2010. december 3., péntek
Diamond dust parhelia on 29 November 2010 from Kontiolahti snowguns
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I screwed up this one. The condidionts were on and I was waiting in Mustavaara for three hours for them to start the snowguns while there was actually diamond dust from Kontiolahti biathlon stadium snow gunning not far from Mustavaara. Eventuallly I saw the Kontiolahti swarm in the distance as I walked up the Mustavaara flank. After three km of driving I entered the diamond dust and got a couple of photos from parhelia against pine forest. The ice fog extended at least 12 km from the source, but I was still deep within. Who knows how far it reached.
I screwed up this one. The condidionts were on and I was waiting in Mustavaara for three hours for them to start the snowguns while there was actually diamond dust from Kontiolahti biathlon stadium snow gunning not far from Mustavaara. Eventuallly I saw the Kontiolahti swarm in the distance as I walked up the Mustavaara flank. After three km of driving I entered the diamond dust and got a couple of photos from parhelia against pine forest. The ice fog extended at least 12 km from the source, but I was still deep within. Who knows how far it reached.
Spotlight halos from Mustavaara snowguns 23/24 November 2010
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The moon halos disappeared as the cloud got thicker and I headed back to Joensuu. The wind was even stronger now, with snowdrift and snowdevils on the road and snow dropping off the trees. On the way at the quarry, however, there was a swarm and I took there some photos with positive and negative lamp elevation. Nothing special, but the photos show nicely the effect of varying crystal tilts on halos. Eventually the swarm died off and moon was shining again surrounded by 22° halo in high clouds.
The moon halos disappeared as the cloud got thicker and I headed back to Joensuu. The wind was even stronger now, with snowdrift and snowdevils on the road and snow dropping off the trees. On the way at the quarry, however, there was a swarm and I took there some photos with positive and negative lamp elevation. Nothing special, but the photos show nicely the effect of varying crystal tilts on halos. Eventually the swarm died off and moon was shining again surrounded by 22° halo in high clouds.
Moon halos from Mustavaara snowguns 23/24 November 2010
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When it is windy you don't get diamond dust halos in Finland. For some reason (could it be that in still weather radiative cooling is stronger and thus relative humidity can rise to reach ice saturation?) there is not enought moisture in the air for ice crystal growth in windy weather. This night is was windy but I nevertheless drove 25 km to Mustavaara to check the situation. As expected there was no diamond dust and I was thinking of going back to Joensuu. Still it looked like it was on the treshold so I decided to wait. This paid off as eventually the ice fog from the snow guns starting spreading and 22° halo was seen in it. Further away the display was a bit better, with also parhelia visible (there was also high cloud in the background, which may have partly contributed to the display, in the second photo the 22° halo on the left is in high clouds). I tracked the cloud extent to 10 km from the source but at that time it was already receding, so probably it was wider at its best.
So this display broke the "no wind" curse for me in Finland. At polar areas where it is hardly ever calm, diamond dust halo displays seem to occur at any wind speeds.
When it is windy you don't get diamond dust halos in Finland. For some reason (could it be that in still weather radiative cooling is stronger and thus relative humidity can rise to reach ice saturation?) there is not enought moisture in the air for ice crystal growth in windy weather. This night is was windy but I nevertheless drove 25 km to Mustavaara to check the situation. As expected there was no diamond dust and I was thinking of going back to Joensuu. Still it looked like it was on the treshold so I decided to wait. This paid off as eventually the ice fog from the snow guns starting spreading and 22° halo was seen in it. Further away the display was a bit better, with also parhelia visible (there was also high cloud in the background, which may have partly contributed to the display, in the second photo the 22° halo on the left is in high clouds). I tracked the cloud extent to 10 km from the source but at that time it was already receding, so probably it was wider at its best.
So this display broke the "no wind" curse for me in Finland. At polar areas where it is hardly ever calm, diamond dust halo displays seem to occur at any wind speeds.
2010. december 2., csütörtök
Spotlight halos from Mustavaara snowguns 17/18 November 2010
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The moon halo display vanished as it got eventually overcast. It was still low stratus with occasional fog on the ground, but apparently the moisture just became too much for the snow guns' ice dust to nucleate a hole. Diamond dust nevertheless continued under cloudy skies and I turned on the spotlight. It was rather good, plate crystals still in charge and with negative elevation lamp (about 11° below horizon) there appeared several "super"-halos (equal to "sub"-halos when light is above the horizon). All were visible to the naked eye, the superparhelic circle at the superanthelic region was bright. At its best the superparhelic circle extended all the way to the superparhelia but I did not get that stage photographed. At the same time was also normal parhelic circle visible. I though of seeing a ghost of super-120° parhelion, but decided it was just white snow on the far hill. In the photos, however, super-120° parhelia are visible in a similar ghostly manner, so probably that was what I saw.
Getting these photos was mostly waiting. Mainly it was water fog, but then, for maximum few minutes at a time good crystal swarms swept by. In one exposure both water fog and diamond dust stage was captured so that there is also fogbow visible. In reality halos and fogbow were not much visible at the same time. Water fog and diamond dust don't just occur simultaneously. Eventually it got worse and I headed back to Joensuu. But on the way there was diamond dust at the quarry, 7 km as the crow flies from Mustavaara. So I took some photos there as well, climbing up a gravel mountain, leaving the lamp at the bottom and thus obtaining about 35° negative light source elevation.
The moon halo display vanished as it got eventually overcast. It was still low stratus with occasional fog on the ground, but apparently the moisture just became too much for the snow guns' ice dust to nucleate a hole. Diamond dust nevertheless continued under cloudy skies and I turned on the spotlight. It was rather good, plate crystals still in charge and with negative elevation lamp (about 11° below horizon) there appeared several "super"-halos (equal to "sub"-halos when light is above the horizon). All were visible to the naked eye, the superparhelic circle at the superanthelic region was bright. At its best the superparhelic circle extended all the way to the superparhelia but I did not get that stage photographed. At the same time was also normal parhelic circle visible. I though of seeing a ghost of super-120° parhelion, but decided it was just white snow on the far hill. In the photos, however, super-120° parhelia are visible in a similar ghostly manner, so probably that was what I saw.
Getting these photos was mostly waiting. Mainly it was water fog, but then, for maximum few minutes at a time good crystal swarms swept by. In one exposure both water fog and diamond dust stage was captured so that there is also fogbow visible. In reality halos and fogbow were not much visible at the same time. Water fog and diamond dust don't just occur simultaneously. Eventually it got worse and I headed back to Joensuu. But on the way there was diamond dust at the quarry, 7 km as the crow flies from Mustavaara. So I took some photos there as well, climbing up a gravel mountain, leaving the lamp at the bottom and thus obtaining about 35° negative light source elevation.
Moon halos from Mustavaara snow guns 17/18 November 2010
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This display was a result of low Stratus turning into ice crystals. It was right on when I arrived with car to the scene, which made me regret my idling in the comfort of indoors. The nucleating agent was the ice dust from Mustavaara snowguns. Essentially this created a punch hole in the cloud layer. All around this few kilometers wide opening it was overcast. Moon was three days short of full and an all sky plate crystal display was seen. The best of the crystal swarm moved back and forth and I tried to follow it with car.
This display was a result of low Stratus turning into ice crystals. It was right on when I arrived with car to the scene, which made me regret my idling in the comfort of indoors. The nucleating agent was the ice dust from Mustavaara snowguns. Essentially this created a punch hole in the cloud layer. All around this few kilometers wide opening it was overcast. Moon was three days short of full and an all sky plate crystal display was seen. The best of the crystal swarm moved back and forth and I tried to follow it with car.
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