[HN Gopher] Researchers explore how storms on Earth create extre...
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Researchers explore how storms on Earth create extreme bursts of
radiation
Author : pseudolus
Score : 68 points
Date : 2021-02-19 11:37 UTC (11 hours ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| swayvil wrote:
| I heard that lightning is triggered by cosmic ray particles. A
| seed in a supersaturated solution situation.
|
| And cosmic rays always come from very very far away.
|
| So a lightning bolt is literally an amplified message from
| beyond.
| temp0826 wrote:
| I don't think that's always the case as it doesn't really
| account for ground-to-cloud lightning strikes
| swayvil wrote:
| Well I dunno about "always the case", but it's certainly
| accountable for ground-to-cloud.
|
| What the seed does is create a place of high potential. I
| think which way the lightning flows is arbitrary at that
| point.
| dms_ucsc wrote:
| The case in the paper I linked above was an intracloud
| flash, but nearly all cloud-to-ground flashes also start
| with a breakdown up in the cloud, so I agree that any model
| of lightning initiation can apply to both intracloud and
| cloud-to-ground flashes.
| swayvil wrote:
| Navajo mythology says that a man who was struck by
| lightning cannot be trusted. Not because he's evil or
| damaged, but because he has been touched by profound
| alienness. He's too weird to predict.
| dms_ucsc wrote:
| People in the field have gone back and forth on this, but you
| might like this paper, which is the best piece of evidence I've
| seen for it in a specific case of a specific flash. Look in
| particular at Figure 6 to see the lightning breakdown starting
| just at the ionization front (curved surface) of the cosmic ray
| shower:
| https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...
| ryder9 wrote:
| no it's not, that's not how lightning works
| snarfy wrote:
| If I have to be careful with 20kv discharges generating x-rays,
| certainly it's within the realm of possibility that lighting
| bolts are generating y-rays, no?
| maxerickson wrote:
| They want to figure out the details of why and how it happens.
| Double_Cast wrote:
| I think snarfy is expressing incredulity that meteorology
| doesn't already account for these types of emmissions.
| Analogously, suppose the headline had read
|
| > _Water flows downhill. Scientists want to know why._
|
| "But gravity makes _everything_ flow downhill, right? What
| makes water especially worthy of investigation. " Surely this
| is a reasonable reaction.
| dms_ucsc wrote:
| I agree it is. And C.T.R. Wilson was talking about it in
| 1925. But the TGFs mentioned in the article are incredibly
| bright, and what we're trying to understand (I work in this
| field) is why one lightning flash makes only a modest
| amount of x- and gamma-rays, kind of what you might naively
| expect, and another makes a mind-boggling million times as
| many, which is not as simply understood.
| maxerickson wrote:
| We don't entirely have a mechanistic explanation for
| gravity either.
| spijdar wrote:
| Yeah, I'm not a physicist sort, so I wouldn't know, but I
| was under the impression that while we have a good model
| for the "what" of gravity in most "classical" scenarios,
| and we can even model some weird gravity effects in weird
| situations, not all of the "whys" are answered and people
| don't know how to model gravity together with other
| phenomena.
| orbital-decay wrote:
| _> Crucial to their plans was making cheap, tabletop g-ray
| detectors that they could install in dozens of sites._
|
| On a related note: there's a citizen science experiment that uses
| a volunteer-run array of old smartphones with taped over cameras
| to detect particle showers caused by ultra-high energy cosmic
| rays.
|
| https://en.wikipedia.org/wiki/Cosmic-Ray_Extremely_Distribut...
|
| https://arxiv.org/abs/2010.08351
|
| https://arxiv.org/abs/1410.2895
| marcodiego wrote:
| Always thought it was a case of Bremsstrahlung:
| https://en.wikipedia.org/wiki/Bremsstrahlung
| DebtDeflation wrote:
| https://archive.is/zpyoo
|
| You can find PDFs of that article if you search. It's
| fascinating.
| FiatLuxDave wrote:
| I read this mainly to see what Dr. Dwyer was up to in regards to
| this. I was in the same grad school as his group at FIT. I was
| also working on gamma ray detectors at the time, so we would
| occasionally talk. Their big challenge was the range of the rays
| in the atmosphere. But I also think that they had a lot of fun -
| they would initiate lightning strikes by shooting rockets into
| clouds. That way they knew where to set up their detectors.
|
| http://www.lightning.ece.ufl.edu/PDF/Dwyer_et_2009a.pdf
|
| https://en.wikipedia.org/wiki/Lightning_rocket
|
| https://www.youtube.com/watch?v=buSaGIoNXu8
| cmehdy wrote:
| > initiate lightning strikes by shooting rockets into clouds
|
| That's what should be shared when people think that science
| isn't heavy-metal enough.
| Shivetya wrote:
| Reading the wiki and some related patents I am curious how many
| such rockets would be required to sufficiently protect a region
| from random lightning strikes.
|
| Are there methods to determine the potential for a storm to
| generate lighting or simply how much energy is potentially
| there to create them?
| FiatLuxDave wrote:
| Its not my field, but I'm pretty sure that the potential for
| a storm to generate lightning is strongly related to the CAPE
| (convective available potential energy), which is often
| measured by meteorologists using sounding balloons, or I
| presume, using more modern indirect (radar,lidar) methods.
|
| https://en.wikipedia.org/wiki/Convective_available_potential.
| ..
|
| I live in Florida, where we have a fairly high frequency of
| lightning strikes (although nothing like Congo). Here is a
| map of global lightning strikes per year per km^2.
|
| https://en.wikipedia.org/wiki/Distribution_of_lightning#/med.
| ..
|
| Whether a single rocket system would drain enough charge from
| a storm to prevent other lightning strikes, I don't know.
|
| I used to think about how to set up a continuous conduction
| path to the ionosphere as a form of power generation. Any
| material path would likely be destroyed, but in theory a
| stabilized plasma could provide essentially an unending
| lightning strike draining the global atmospheric charge
| imbalance. But, this isn't an easy problem (it's a long way
| up to the ionosphere), and the amount of energy in global
| lightning is surprisingly small when compared to other
| natural sources like solar, tides, geothermal, etc. Very
| concentrated though!
| mncharity wrote:
| Thundercloud Project: Exploring high-energy phenomena in
| thundercloud and lightning (2020)
| https://academic.oup.com/ptep/article/2020/10/103H01/5885093 HTML
| pbuzbee wrote:
| Cool to see this on HN! I worked for Prof. Smith (quoted in the
| article) as an undergrad. TGFs also emit beams of electrons. One
| of my projects was investigating whether we can detect these
| beams of electrons bouncing back and forth along Earth's magnetic
| field lines.
| dms_ucsc wrote:
| Hi, Paul! :) I was sent here by Greg Bowers. -David
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