What conditions are necessary for the sun to look [as described below]

Question

First of all sorry for the weird title. I have no idea how to describe it in a succinct way because I've never heard of something similar happening and I've only witnessed it once. The only way for me to describe this event is in its entirety as parts of it WILL be handwaved as a completely normal occurence.

My mom and I were on the highway and it was approximately an hour away from sundown. There were many "thin" layers of clouds on different altitudes that could clearly be seen but weren't thick enough to completely cover the sky. As some of these layers of clouds moved in front of the sun, the shine became less agressive as one might expect, and as the composition of clouds (?) between us and the sun changed, almost all of the "agressive" shine disappeared, while leaving a bright orange circle that seemed to almost oscillate and warp around its edges. There was absolutely no discomfort looking at the sun, comparable to looking up at the sky when it is completely covered in clouds, but the sun was clearly visible as an extremely saturated, deep orange. The edges of it seem to vibrate and shift, almost like it was made out of liquid. After about 2 or 3 minutes the clouds had moved and shifted in such a way that the sun returned to "normal" and looked more like one would expect it to look when looking at it through clouds, or directly having it in your field of view.

Now on the surface I understand that this sounds as weird as the time I'm having trying to describe it. But both me and my mom had never seen anything like it and what really drove home the point that we're witnessing something extraordinary was that the entire speed of the moving traffic almost halved within seconds of the event starting. Those minutes were actually very scary traffic safety wise, as several cars were swerving and slowed down harshly. Seemingly everybody on the road was witnessing something spectacular, so my question is simply if anybody out there has a bell ring when mentioning these specific observations. In my head I've convinced myself we were watching sunstorms while the sun was "vibrating" and had almost flowing edges, but realistically this seems more related to the movement of different cloudlayers (although once again I have to stress, this did not look like anything you or I have seen before unless you know exactly what visual phenomenom I'm talking about, and it's not comparable in the slightest to watching clouds go over the sun normally). The only way to summarize it is like we put on some kind of glasses that removed all kinds of "rays" from the sun but left the main structure glowing. The only time I've witnessed something this unusual in the sky was when we were on a large hill and observed one of the blood moons (the ones that are GIANT in the sky, maybe they're not called blood moons) coming up just over the horizon and it looked like something straight out of a sci-fi movie when the atmosphere zoomed in on it.

Once again my apologies for a random and weird question that might not even be on the right stack exchange(maybe simply an optics question?), but it's something I've thought about a few times and after spending time all around the network and I figured if there's any chance of finding an answer to what we witnessed that day, the person with that answer might be somewhere on here. I also have no idea where else I would ask this question as I've NEVER heard anything about this and it was more beautiful than northern lights (probably because of its rarity, but still).

Thanks!!

Answer 1

tl;dr I’ve experienced a similar thing, probably pollutants and some refraction caused it to become the color and intensity it did and to shimmer

I have actually had a similar experience, but with the two features of what you’re describing spread over two events.

The first was dusting the solar eclipse of ~2017ish (give or take a year, it was the one that had a lot of coverage in the US). I was at the time in an area where it was only a partial eclipse but the clouds/ fog of that day was in such a way that, similar to your experience, it was easier to have my eyes get close to it. I refrained from looking at it, because even in those conditions it can still harm your eyes, but it appeared to be the same kind of “less aggressive” shine that you described. I think I might still even have pictures of it somewhere.

The second experience was near the same area where there were some absolutely massive forest fires nearby, and the sun turned a deep orange color from the ashes.

It’s a common occurrence (and often times problem) that dust extinction can absorb the bluer part of the spectrum from a star. We most often care about the dust between us and a distant star (say, in another part of the galaxy where there’s a lot of dust between us and it) because it affects visibility of stars in different wavelengths. The way we’re still able to look at objects through the dust is through infrared light (and other longer wavelengths)

Since the sun emits as a black body spectrum with its peak in the optical light, without any atmospheric blocking, the sun appears white. As you block out more and more of bluer wavelengths with dust particles that are densely packed and just the right size (which would depend on their molecular structure) then you get these redder/ orangeish hues you see in the sun. Normal water vapor often times isn’t enough to get these redder colors, as water mist absorbs in the UV but not as much in the optical, so while it makes it the more yellow color we come to know and love, it takes other kinds of elements (normally in the form of some kind of pollution) to make these colors you see.

Since the bluer the light, the higher energy the light, and also since the cloud passing by was probably a mix of pollutants and water vapor, the combination of all that probably removed a lot of the higher energy wavelengths and reduced the intensity of those that remained to the point where you observed what you did. As for the edges vibrating, this could possibly be a refraction effect from the differing temperatures of the cloud, similar to how you see the air shimmer near hot pavement. It could potentially be something else, but it’s hard to know for sure without seeing it first hand.

Hope that helps!