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Deme

Interested in weather, meteorology and photography. Aviation weather observer.

Other account: @[email protected]

Posts
34
Comments
45
Joined
2 yr. ago

🐸 time

  • An extreme value is always only extreme in relation to some baseline. For temperatures it's usually a value that departs far from the local average. With WBT it can also mean values that approach the limit of what the human physiology can handle, a value that is quite universal due to us all being of the same species. The body cannot adapt beyond the limits set by thermodynamics.

    Tropical and extreme aren't mutually exclusive. +30°C in Antarctica would be both tropical and extreme. Both are used where applicable. A temperature can also be extreme without being tropical. No matter what Trump thinks, he doesn't have the power to redefine (let alone erase) words.

    The wet bulb temp. in a proper sauna should get quite high, I don't have exact numbers but above 70°C or so (dry temp. 90°C, relative humidity 50% would translate to a WBT of 74°C). In most contexts that would be extreme, but not here.

  • 🐸 time

  • *Extreme WBT's

    A wet bulb thermometer measures wet bulb temperature (WBT), which is a metric that always exists and can always be measured. It only gets bad when the WBT reaches an extreme value, as is the case for basically all environmental metrics. Saying that wet bulb temperature is lethal is like saying that temperature is lethal. Look out for temperature! I'm sorry for the rant so I'll try to keep this short, but "wet bulb" by itself in this context is an inane shorthand that lacks all the significant words and muddles the meaning of those words that are in it. Scientists talk about Extreme WBT events, because that's what they are. A less of a mouthful would be nice for science communication, but I don't want it to come at the expense of words losing meaning like that.

    Heatwave is a nice and descriptive word for one type of an extreme temperature event. Cold snap is another one. I'm glad neither is called "temperature event" because that would be dumb.

  • Nice! Altocumulus stratiformis undulatus, but with two intersecting systems of undulations. Think of them like cross waves at sea.

  • 196 @lemmy.blahaj.zone
    Deme @lemmy.world

    Various rules

  • Thanks! Time really is the most important ingredient. Look at enough sunsets and sunrises with an adequate camera on hand, and every now and then a great scene will come up. After that it's just point and shoot.

  • pics @lemmy.world
    Deme @lemmy.world

    Shallow fog and Cirrus at sunrise today

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Cirrus, including some Cirrus spissatus at sunrise today

    pics @lemmy.world
    Deme @lemmy.world

    Condensation and diffraction

  • Thanks!

  • Thanks! Yes, it is a photo. The moth was chilling on a window after sunset. The blue dots are out of focus apron lights.

  • pics @lemmy.world
    Deme @lemmy.world

    Disillusionment

  • They sure don't tend to do that, but there are still mundane explanations for this. An unintentional collision between the satellite and another object being one of them.

    "I find it hard to believe they would use such a big satellite as an ASAT target," McDowell said.

  • Not because of Kessler syndrome, just your run of the mill space debris reentering the atmosphere and increasing the amounts of certain metals up there that contribute to ozone depletion. In other words, that may well happen even if we're lucky and avoid Kessler syndrome.

  • Posio, southern Lapland, Finland

  • Posio, southern Lapland, Finland

  • pics @lemmy.world
    Deme @lemmy.world

    More Aurora borealis from last week

    This one turned out a bit more blurry, but the aurora itself is too good not to post here.

    pics @lemmy.world
    Deme @lemmy.world

    Aurora Borealis last week

    These guys danced accross the sky, reaching quite far into the southern sky as well. Picture taken on 4.4.. I'm just mad that while I had hauled my tripod with me, I had left the camera mount back home :))). I stuck a bench into the snow and steadied my hand against that. A couple of these turned out surprisingly well.

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Cirrus uncinus radiatus

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Cirrostratus fibratus and a 22° halo

    Cirrus and Cirrostratus progressively invading the sky are a telltale sign of an approaching warm front. In this case it was an occluded front that was rolling in. It snowed that night.

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Snow shower

    Don't be decieved by the anvil like shape, heavy looking precipitation and icy look of this cloud! This is far from the size and power of an actual Cumulonimbus. But it is interesting in that it fits every criteria of a Cumulonimbus capillatus incus, except the bit about considerable vertical extent for the genus. I'm quite sure that this guy didn't raise its head much above 2 km AGL.

    I suppose it could be classified as a Cumulus of some sort, but it really doesn't fit well under any genus. Our systems of classification are just something that we made up. Clouds are under no obligation to conform to them. The same is true for everything else in the universe as well.

  • Almost forgot to get back to you about that last part: Yes it did, but this wasn't that.

    Here's a picture I took when the smoke was making a sunset unusually red:

  • This was a telephoto at the horizon at around midnight. The sun was only a bit above the horizon, so the lighting was similar to a sunset/sunrise.

    Here's another picture of that same midnight, looking towards the sun.

  • Nah winters are beautiful up north. Sometimes also in the south, but only rarely around the southern coast.

  • You're welcome!

  • Clouds @sh.itjust.works
    Deme @lemmy.world

    The most well developed fluctus I've seen. Altocumulus stratiformis fluctus

    Picture taken in August 2022. Fluctus, also known as Kelvin-Helmholtz wave clouds, form when wind shear causes instability in the (usually the upper) surface of a cloud. The formation is short lived and relatively rare. It can also only be seen well from the side like here. This video contains a good explanation of the physics involved here.

    pics @lemmy.world
    Deme @lemmy.world

    Nightless nights of summer

    Taken last summer from Riisitunturi, Posio, Finland.

    pics @lemmy.world
    Deme @lemmy.world

    The sunset today was quite something.

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Altocumulus with a lot of virga shortly after sunset today

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Cirrocumulus stratiformis with cloud iridescence

    Some of the Cc is of the variety undulatus. Miscellaneous Cirrus in the lower part of the image.

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Cirrus fibratus and a sun pillar

    Picture taken on 25.6.2023 at 01:27 local time.

    A sun pillar is formed when horizontally floating hexagonal ice crystals (in this case within the Cirrus) reflect light. Kinda like the reflection of the setting sun over wavy water, but in this case upside down.

  • Thanks for notifying. Should be fixed now.

  • Accidental Renaissance @lemmy.blahaj.zone
    Deme @lemmy.world

    Shallow fog and sunshine

  • Thanks! That day was beautiful.

  • pics @lemmy.world
    Deme @lemmy.world

    Shallow fog and sunshine

    Picture taken in December 2022, Helsinki.

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Skyway (Altocumulus lenticularis)

    Image taken in the summer of 2022.

    Clouds @sh.itjust.works
    Deme @lemmy.world

    Altocumulus floccus, a sure sign of instability. Last summer.

  • I've seen this guy in a virgin vs. chad meme and now here. Who are they?

  • Israelis Hijack Hamas.com, Turning It Into a Display of October 7 Atrocities

  • A good point