[HN Gopher] Unexpected solar weather is accelerating satellites'...
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Unexpected solar weather is accelerating satellites' orbital decay
Author : lelf
Score : 84 points
Date : 2022-06-23 16:36 UTC (6 hours ago)
(HTM) web link (www.space.com)
(TXT) w3m dump (www.space.com)
| rcardo11 wrote:
| I'm wondering if this solar cycle can be a reason for the recent
| wild summer temperatures? Anyone here can confirm?
| daltont wrote:
| Hyperbolic headlines plus the fact the people tend to not read
| anything except the headline (a form Lem's law IMO) is part of
| the disinformation problem.
| FunnyBadger wrote:
| This is simply part of the solar cycle. And it's a standard part
| of satellite planning when it comes to operational quality and
| reliability to account for solar cycle radiation effects.
|
| This is an ignorant fear article and/or an article written by
| someone who knows NOTHING about space launch and design.
|
| (I used to be a military rocket scientist specializing in
| radiation effects on space electronics many moons ago).
| kmbfjr wrote:
| >By coincidence (or beginner's luck), the onset of the new
| space revolution came during that sleepy solar cycle.
|
| Apparently not simply part of the solar cycle when new types of
| spacecraft (lacking typical propulsion systems) haven't been in
| orbit during a high activity solar peak.
|
| There are some points that are alarmist. "Plummet" isn't
| something that seems to happen.
| KennyBlanken wrote:
| The article _at length_ describes how this solar cycle is
| _different from prior cycles and forecasts_.
|
| > This drag also helps clean up the near-Earth environment from
| space junk. Scientists know that the intensity of this drag
| depends on solar activity -- the amount of solar wind spewed by
| the sun, which varies depending on the 11-year solar cycle. The
| last cycle, which officially ended in December 2019, was rather
| sleepy, with a below-average number of monthly sunspots and a
| prolonged minimum of barely any activity. But since last fall,
| the star has been waking up, spewing more and more solar wind
| and generating sunspots, solar flares and coronal mass
| ejections at a growing rate. And the Earth's upper atmosphere
| has felt the effects.
|
| > In late 2021, operators of the European Space Agency's (ESA)
| Swarm constellation noticed something worrying: The satellites,
| which measure the magnetic field around Earth, started sinking
| toward the atmosphere at an unusually fast rate -- up to 10
| times faster than before.
|
| > By coincidence (or beginner's luck), the onset of the new
| space revolution came during that sleepy solar cycle. These new
| operators are now facing their first solar maximum. But not
| only that. The sun's activity in the past year turned out to be
| much more intense than solar weather forecasters predicted,
| with more sunspots, more coronal mass ejections and more solar
| wind hitting our planet.
|
| > "The solar activity is a lot higher than the official
| forecast suggested," Hugh Lewis, a professor of engineering and
| physical sciences at the University of Southampton in the U.K.
| who studies the behavior of satellites in low Earth orbit, told
| Space.com. "In fact, the current activity is already quite
| close to the peak level that was forecasted for this solar
| cycle, and we are still two to three years away from the solar
| maximum."
|
| > Stromme confirmed those observations. "The solar cycle 25
| that we are entering now is currently increasing very steeply,"
| she said. "We do not know if this means that it will be a very
| tough solar cycle. It could slow down, and it could become a
| very weak solar cycle. But right now, it's increasing fast."
| walrus01 wrote:
| I concur with this, and also, one possible solution to this
| from a technical perspective is to increase the amount of fuel
| carried for ion/hall effect and similar thrusters (high
| specific impulse, low thrust) for periodic orbit raising
| maneuvers to extend lifetime.
|
| _Theoretically_ , as $ per kg launch costs come down with
| things like reusable falcon 9, it makes it much less costly to
| equip medium sized LEO satellite with more fuel than it might
| have costed 10 or 15 years ago.
|
| Or if you have something that needs to orbit really low and
| minimize drag/maximize lifespan, you could design it to be
| particularly aerodynamic and shaped like this:
|
| https://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State...
| zackees wrote:
| So this effect is caused by more solar wind slamming into the
| atmosphere at 100's of km/hr and is so powerful that it's CAUSING
| THE ATMOSPHERE TO HEAT UP AND EXPAND?
|
| Does the global warming models take this into effect? This seems
| like an unfathomable amount of energy.
| jhgb wrote:
| It's causing _the uppermost layers of atmosphere_ to expand.
| That 's less than an unfathomable amount of energy because the
| uppermost layers of atmosphere are extremely rarefied, to the
| extent they don't even behave like gases.
| mturmon wrote:
| Solar irradiance variations amount to a bit less than 0.1% over
| the solar cycle. It used to be thought solar-cycle variations
| (the 11-year period) could be a significant contributor to
| climate change.
|
| This turned out not to be the case...that was pretty much known
| by the early 2000s.
|
| Other irradiance variations, due to orbital variations called
| Milankovich cycles, happening in the 10,000's of year range, do
| appear to influence climate. Of course, the extremes we're
| seeing now are not on the 10,000-year time scale.
| kgc wrote:
| I wish we could go back to the days of non-clickbait headlines.
| dragontamer wrote:
| When exactly did those days exist?
|
| * "Destruction of the Warship Maine was the work of an Enemy.
| $50,000 Reward~" https://sophia.smith.edu/fys169-f19/wp-
| content/uploads/sites...
|
| * There's also the fake propaganda Ben Franklin pushed so that
| the 1776 revolution would have the moral high ground. (Ben
| Franklin fabricated the "Scalping" of USA's early citizens to
| fake a war-crime, to make the British look more monstrous).
| https://founders.archives.gov/documents/Franklin/01-37-02-01...
|
| I'm not sure if there ever was non-clickbait headlines. In
| fact, the further back in history you go, the more clickbait,
| and even fully fake, information seems to exist.
| not2b wrote:
| Too many HN threads just seem to be people arguing about the
| appropriateness of the title. The article addresses a significant
| and interesting issue that's going to have major negative effects
| on business models, as well as some positive effect on space
| junk. I think they did a decent job, at least for an article
| intended for the general public, and I'm glad I read it. And yes,
| the word "plummet" is an exaggeration. But that isn't a big deal.
| jandrese wrote:
| Writing a good title is as hard as naming things in code. It's
| a much harder problem than it seems like it should be, with
| mutually exclusive interests often creating impossible
| situations.
|
| But also, people just kind of suck at it.
| dang wrote:
| With media publications, at least, it's more that they have
| specialists dedicated to slathering bait on the titles.
| That's their job and they're perfectly good at it--they just
| don't produce what people _here_ would call a good title.
| This is an example of what Eric Evans called a "bounded
| context". The way I look at it, it's their job to sex up the
| headlines and our job (community as well as moderators!) to
| deflate them again. "Not in this context."
|
| https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que.
| ..
|
| (I suppose this is what you meant by "mutually exclusive
| interests".)
| birdyrooster wrote:
| Bike shedding at work
| brazzledazzle wrote:
| I like to take a break from bike shedding at work with some
| bike shedding on HN. Has a different flavor.
| kzrdude wrote:
| I think HN's current title policy is exactly right, for this
| reason: submissions need "neutral" titles so that we can
| discuss the content instead.
|
| In this case, the discussion of the word plummet is halfway
| topical: it's about understanding the severity and going more
| into detail of what's actually happening, putting it in
| context. The equivalent discussion would happen regardless of
| word choice.
| colechristensen wrote:
| And most aerospace threads are a shitshow, people who have no
| idea what they are talking about getting uppity about words
| which are basically appropriate in this circumstance. Going
| from 2 km/year to 20 km/year orbit decay is indeed quite
| significant and could cause a satellite to be lost many years
| early, the last stage of which is burning up in the atmosphere
| which is quite plummetous.
| andrewflnr wrote:
| Misleading headlines are a constant act of sabotage on our
| ability to prioritize our information intake. I don't know if
| it _really_ needs to be discussed every single time, but it is
| important enough to be recognized and discussed, and until we
| decide to get serious about rebelling or whatever, well, who 's
| going to decide where the exact appropriate place is to discuss
| it? So basically as long as it keeps hurting, were going to
| keep talking about it whenever and wherever it hurts.
| [deleted]
| dang wrote:
| Never underestimate the passion users feel about titles:
| https://news.ycombinator.com/item?id=20429573
| corrral wrote:
| > Too many HN threads just seem to be people arguing about the
| appropriateness of the title
|
| Too many writers--including of headlines--are so sloppy with
| language that it's misleading, or even incorrect.
|
| Perhaps when GPT-4 or whatever takes over those jobs, it will
| be better at it. Provided we don't train it on anything written
| after 2000 or so, when all headlines became tabloid headlines
| and margins got tight enough that no-one had time for careful
| editing anymore.
| topspin wrote:
| "But that isn't a big deal."
|
| It's clickbait. I appreciate people pointing out clickbait. I
| think a lot of others do as well; it's why they read the
| comments on an article before the look at the article.
|
| Had the story been titled "Solar Weather Causes Unexpected
| Satellite Orbit Decay" or some other non-clickbait thing I'd
| have read it without looking at comments first. I'm actually
| interested in solar weather due to its impact on radio. Too bad
| publishers don't understand that clickbait titles are a serious
| turn off. Apparently everything must be TMZ.
| not2b wrote:
| I don't appreciate it when the whole comment section of a
| substantive article is complaints about the headline. Maybe
| we should just have a way for people to privately message the
| moderators proposing a headline change to correct a
| misleading headine, and do that instead. Then the comment
| section could talk about the article instead of the headline.
| anigbrowl wrote:
| This can bel alleviated by choosing better sources or relaxing
| the objections to editing titles. I agree that there are lots
| of useful and informative stories with shitty headlines. I
| personally don't mind title edits as long as they aim to be
| less rather than more sensational, and OP briefly notes the
| reason for the change.
| [deleted]
| RosanaAnaDana wrote:
| HN: come for the pedentry, stay for the pedentry on pedentry.
| jtbayly wrote:
| It's spelled "pedantry." :)
| a9h74j wrote:
| An MP-complete post is one in which the meta-pedantry
| completes in polynominal time.
| dang wrote:
| That has to have been a trap.
| stjohnswarts wrote:
| I mean wouldn't they account for this and add thrusters and fuel
| to put it back where they want it?
| vsllc wrote:
| I am thinking about a commercial data product to address the
| situational awareness need here. It feels daunting though,
| because customers would be the likes of SpaceX and other
| intimidating entities. If anyone has thoughts, or is interested,
| please send me an email. (Contact info in profile!) Thanks.
| visviva wrote:
| Commercial SSA is getting to be a busy... space. Have you seen
| what others are doing in that area? How does your idea differ?
| colechristensen wrote:
| With NASA and related space weather data products and internal
| tracking of satellites being a core competence of companies
| like SpaceX, I don't necessarily see where a commercial data
| product would fit or provide value. Unless you're actually
| going to launch orbital assets and have some significant
| scientific work, I'm just not sure.
|
| Some competition: http://acswa.us/about/members.html
| Treblemaker wrote:
| (December 19, 2020) "The consensus view of an international panel
| of 12 scientists calls for the new cycle, Solar Cycle 25, to be
| small to average, much like its predecessor, Solar Cycle 24.
|
| But a prominent astrophysicist at the National Center for
| Atmospheric Research, Scott McIntosh, foresees the sun going
| gangbusters. The cycle is already off to a fast start, coinciding
| with the recent publication of McIntosh's paper in Solar Physics.
| The study, with contributions from several of his colleagues,
| forecasts the nascent sunspot cycle to become one of the
| strongest ever recorded."
|
| [0] https://www.washingtonpost.com/weather/2020/12/19/solar-
| cycl...
| Treblemaker wrote:
| Update on the prediction:
|
| (Feb. 26, 2022) ""We have finalized our forecast of SC25's
| amplitude," says McIntosh. "It will be just above the
| historical average with a monthly smoothed sunspot number of
| 190 +- 20."
|
| ""Above average" may not sound exciting, but this is in fact a
| sharp departure from NOAA's official forecast of a weak solar
| cycle"
|
| [0] https://spaceweatherarchive.com/2022/02/25/the-
| termination-e...
| jaywalk wrote:
| Is the word "plummet" really appropriate here? They're talking
| about falling at a rate of 0.001mph, which is much faster than
| expected but hardly a "plummet."
| jcims wrote:
| I don't really pay attention that closely, but space.com is a
| common theme when i see hacky stories about space/astronomy.
| martinky24 wrote:
| Pop-sci articles... Always disappointing
| nomel wrote:
| But dang, they sure made me fall in love with science, as a
| kid.
| dylan604 wrote:
| Was this one disappointing? Maybe if you're going by the
| title alone, which granted was the original question.
| However, it was a decent enough explanation for the target
| audience of the site.
| colechristensen wrote:
| Yes, orbit decay having gone up by a factor of ~10 is indeed
| plummeting.
|
| You park things in low earth orbit so that they don't stay up
| forever and indeed come down in reasonably small human-scale
| timeframes. Usually on the time scale of decades, sometimes
| more, sometimes less.
|
| If you designed a satellite to stay up for 10 years, it'll
| suddenly only be able to stay up a year, that's the scale of
| these things.
|
| Again it's an exponential thing, a seemingly small scale change
| in the slow part makes the fast part come quite a lot sooner.
| BitwiseFool wrote:
| I think the primary objection is that to the vast majority of
| people 'plummet' implies the satellite is suddenly and
| violently falling from the sky - it's the kind of word people
| would describe an airplane crash with.
|
| However unless the author happens to know a lot about orbital
| mechanics (or they've played Kerbal Space Program) they
| probably just picked an expressive word for the sake of a
| compelling article rather than something that would give a
| better picture to the layperson.
| orbital-decay wrote:
| Sidenote: KSP is the worst way to build intuition in this
| particular case as it doesn't have any drag model in orbit,
| or even n-body simulation, so no orbital decay is possible
| there. Playing around with NASA's GMAT [0] or similar more
| comprehensive software is much more helpful to understand
| real-world orbital mechanics.
|
| [0] https://sourceforge.net/projects/gmat/
| ericbarrett wrote:
| There is a high-quality mod which adds n-body gravity:
| https://github.com/mockingbirdnest/Principia
|
| It will also add orbital perturbations/frozen orbits if
| you use Real Solar System: https://github.com/mockingbird
| nest/Principia/blob/master/ast...
|
| That said, to my knowledge there isn't yet a mod that
| adds high-altitude drag.
| colechristensen wrote:
| It's a dumb objection. A mission manager was quoted using
| the word "diving".
|
| It isn't the journalist but the nitpicking commentors who
| are clueless. The headline accurately enough conveys what
| is happening and the article articulates it well. Orbital
| mechanics isn't intuitive enough for there to be perfect
| fit words given human experience, human timescales,
| "plummet" is fine.
| nomel wrote:
| The definition of the word, that everyone is probably
| familiar with, strongly disagrees: https://www.merriam-
| webster.com/dictionary/plummet Plummet:
| 1. to fall perpendicularly 2. to drop
| sharply and abruptly
|
| Or, Google's scraped definition from Oxford dictionary:
| fall or drop straight down at high speed.
|
| If you google "satellite plummeting", you'll notice that
| almost all of the results also include "fireball",
| "burning up" and/or "reentry".
| corrral wrote:
| Plummet implies a straight-line dead fall, or close to
| it. It derives from lead weights (hence the similarity to
| "plumber") attached to a line, used for sounding depth of
| water or for marking a straight vertical line. The
| "verbing" of that noun and its figurative use to describe
| falling appear to be quite recent developments--Webster's
| 1913 only lists a noun. I'd say it's the wrong word for
| this case, but then I'm an opponent of using slightly-
| similar words interchangeably, such that we effectively
| have fewer words to work with. However, I'm losing that
| fight anyway, so who cares I guess.
|
| [EDIT] On reflection, this is even goofier than I thought
| at first, since the choice of lead for those applications
| is precisely because it's little affected by wind, and
| even fares better than most things against moving water,
| while this is entirely about something falling faster
| _because of_ its interaction with air.
| BitwiseFool wrote:
| I don't see why it is a dumb objection. Word choice is
| important, especially for journalists trying to convey
| information to the general public and even more so when
| it comes to headlines - as the majority of people won't
| read the article to understand the nuance.
|
| I genuinely think a decent number of people are going to
| envision a situation where satellites suddenly plunging
| out of orbit like they would in some big budget disaster
| movie. You are well within your right to tell them they
| are thinking of the word "plummeting" incorrectly but you
| are fighting an uphill battle. Technical and dictionary
| correctness has its place but to convey information
| properly people must consider the vernacular.
| teawrecks wrote:
| > I don't see why it is a dumb objection
|
| Because we're now 5+ comments deep arguing semantics. You
| know the facts, I know the facts, we all know the facts,
| what do we disagree on?
| colechristensen wrote:
| It's dumb because it is based on the objector imagining
| what an uninformed reader would imagine and thinking that
| anything unlike mighty Thor smiting satellites out of the
| sky with lightning bolts would make the word "plummet"
| inappropriate.
|
| Satellites are falling relatively very fast compared to
| usual and some of them have or soon will burn up in
| atmosphere as a result, it's a headline, not a half
| sentence expected to grant a degree in astrodynamics.
| BitwiseFool wrote:
| Likewise, why would you imagine that an uninformed reader
| would see the word "plummet" and understand that none of
| these satellites are in immediate danger of re-entry,
| that they will in-fact continue to stay aloft for several
| more months, and that in this context plummet means an
| orbit decaying an order of magnitude faster than
| expected?
|
| You are correct, one of the meanings of plummet is a
| rapid descent. These satellites are rapidly descending.
| You are correct.
|
| Again, though, word choice matters. Can you see where
| other commenters and I are coming from?
| cardiffspaceman wrote:
| Remember that Star Trek movie trailer wherein the
| Enterprise (or a similar) spacecraft seemed to drop like
| the string had been cut? That's what I picture with
| "plummet".
| [deleted]
| GekkePrutser wrote:
| But this space 'weather' won't last forever right? Won't it
| go back to the old decay rate after this?
|
| So if it lasts a week, the lifetime will be reduced by 10
| weeks? Still a lot but something you can cope with.
| colechristensen wrote:
| There are events measured in minutes, hours, and years (or
| decades).
|
| We're ramping up to a maximum which should happen in a few
| years but activity has been above predictions. We don't
| understand the Sun dynamics all that well, but what's
| happening now is a little weird beyond expectations and
| might be something that continues for years.
| dylan604 wrote:
| Just finished reading the article with the exact same question
| in mind.
|
| Plummet gets the clicks though, so to the website, it is
| appropriate.
|
| It could also be argued it's a sense of perspective. Something
| that falls at the rate of 2km per year suddenly in a matter of
| months starts to fall at a rate of 20km per year could seem
| like plummeting when you're the one tasked with keeping it
| alive or the person that paid for it to be there for 10 years
| to see it suddenly shortened to 2 years. It's a stretch, but we
| all love hyperbole
| uranium wrote:
| This. To space folks, that _is_ plummeting. It 's enough of a
| difference, and a surprise, to have a significant effect on
| business models.
| Aachen wrote:
| It's a significant difference that has a real impact on the
| satellites. But we also don't say that airplanes plummet
| when landing or elevators when going down.
|
| To me at least, plummet signals it's a matter of seconds
| or, perhaps from great altitude, minutes until it hits the
| bottom. So to me, and that's knowing a thing or two about
| space, this title is just clickbait and not a good
| description of the phenomenon observed even for a techy
| public like HN.
| [deleted]
| dylan604 wrote:
| We absolutely refer to planes as plummeting, when the
| situation warrants.
|
| This article wasn't written for HN. It was written for
| the general audience that peruses Space.com. Because
| someone found it interesting and posted to HN is pretty
| much the only reason it is on HN. Space.com didn't submit
| it in hopes of gaining attention by a hypercritical
| audience.
|
| Yes, I agree it is click bait. I'm just playing devil's
| advocate to some of your weaker arguments.
| perihelions wrote:
| They also say Starlink fully lost 40 satellites to solar
| weather (were decelerated rapidly enough to burn up in the
| atmosphere, before their orbits could be rescued). There's a
| range of outcomes.
|
| Thread about that:
|
| https://news.ycombinator.com/item?id=30267587 (488 comments)
| mirashii wrote:
| For those who don't click through to the other thread, I'd
| say that solar weather contributed, but the root cause was
| more an overzealous safe mode induced by the operations team
| that didn't leave time to recover. A better operations plan
| would've shortened the safe mode duration to ensure that they
| attempted to raise their orbit even if it meant deploying
| during the solar event. Letting safe mode destroy the
| satellite to mitigate a probabilistic risk is just bad
| planning. Take the chance and deploy anyways and hope you get
| lucky.
| daniel-cussen wrote:
| Come on, 40 satellites is not all that much for Spacex.
| adolph wrote:
| > Take the chance and deploy anyways and hope you get
| lucky.
|
| If they got unlucky they might have spiked a space in which
| another satellite could have orbited (no pun intended).
| dang wrote:
| Alright you guys, they are no longer plummeting in the title
| above. Let's talk about the interesting bits now!
| cperciva wrote:
| I would have said "... is accelerating satellites' orbital
| decay".
| dang wrote:
| Ok, it's up there now. Thanks!
| CodeWriter23 wrote:
| Well at that rate, it will crash into the Earth in...never
| dr_orpheus wrote:
| But it will though. The lowest satellites are at an altitude
| of 460 km above the Earth. And the decay of the satellite in
| to the Earth is exponential [0] so the unexpected drop is a
| significant impact on the lifetime of the spacecraft. You can
| see from the plot in that Orbital Decay that there is an
| altitude that it starts dropping very rapidly. So they may
| have expected it de-orbit in approximately 10 years, but now
| the de-orbit could be something like 5 years.
|
| https://en.wikipedia.org/wiki/Orbital_decay#/media/File:Alti.
| ..
| [deleted]
| Eddy_Viscosity2 wrote:
| I'm surprised they didn't go all out and call 'solar weather'
| 'extreme nuclear explosion activity on the sun'. I'm mean, if
| its for the clicks, why not.
| mc32 wrote:
| Yeah, plummet is like straight down till it hits something.
| Given it's root is in "plumbum" it's not surprising and yes,
| this is used incorrectly. Not being prescriptive, but this
| usage is pretty misleading.
| pempem wrote:
| Well now that we've determined that plummet maybe isn't the
| right word to use, shall we discuss the fact that satellites
| are unexpectedly falling from the sky in yet another climate
| change that we had not predicted?
| mc32 wrote:
| While solar phenomena influences climate, this aspect is
| not human induced. We have put artificial satellites up
| there, in earth orbit, but they are not causing solar
| eruptions or solar flares. We don't understand solar
| "climate" enough to say that it's changing (cycle
| frequency, amplitude, etc).
| bityard wrote:
| > We don't understand solar "climate" enough to say that
| it's changing (cycle frequency, amplitude, etc).
|
| We certainly do know a fair amount about the sun's
| "climate": https://en.wikipedia.org/wiki/Solar_cycle
|
| The sun has an 11-year solar cycle where each cycle has a
| period of low and high sunspot activity and currently we
| are just starting Cycle 25 with a corresponding uptick of
| solar flare activity.
| jtbayly wrote:
| If only we hadn't been burning fossil fuels, the sun
| wouldn't be punishing us like this!
| pempem wrote:
| Climate of the sun. ugh. climate of the sun obviously.
| zoomablemind wrote:
| > ...shall we discuss the fact that satellites are
| unexpectedly falling from the sky
|
| Well, the falling is rather expected, it's just the rate of
| it is faster, than we hoped for.
|
| Maybe in a couple of years, once at max, the rate will
| start decreasing, but for some cubesats this may be
| terminal by then.
| anigbrowl wrote:
| I think this is widely predicted actually
| furyofantares wrote:
| That's what's happening, right? It's just that space is
| curved by the earth
| mc32 wrote:
| A meteor/meteorite plunges to earth. Something that lowers
| its altitude so very slightly is not "plummet". Skylab yes
| plummeted back to earth.
| izzydata wrote:
| Wow, so you are telling me satellites are falling to earth and
| burning up in the atmosphere? No? Oh.. ok.
| kzrdude wrote:
| No? Yes. They always do this. The only question is how fast.
| They'll fall and burn eventually.
| [deleted]
| zoomablemind wrote:
| There were some space tech startups planning to provide a kind of
| tug-service to satellites on the low orbit. Not sure if any
| viability for this is on the near-future horizon.
|
| Space tugs as a service: https://spacenews.com/space-tugs-as-a-
| service-in-orbit-servi...
| mturmon wrote:
| As people are pointing out, the rate of orbital decay does matter
| (even if it's not a "plummet"!) -- because everyone concerned
| knows that solar activity should be increasing _to some extent_
| in 2022 as a new solar cycle takes hold.
|
| This plot of sunspot activity, and the (highly correlated) 10.7cm
| radio flux, indicates that the current cycle (cycle #25) is
| rising much faster than typical:
|
| https://www.swpc.noaa.gov/products/solar-cycle-progression
|
| As you can see, cycle #24, which ended in 2019, was quieter than
| expected (annoying to solar physicists who only see a few cycles
| within their whole career) -- so it's actually very interesting
| that Cycle #25 is starting out with a bang.
|
| NOAA is the main US government agency tasked with
| monitoring/predicting solar activity for the protection of ground
| and space systems. The main facility is the Space Weather
| Prediction Center which is in Boulder, CO -- that's the data
| source of the above plots. The SWPC centerpiece used to be a
| control room with a bunch of people looking at computer monitors
| filled with various real-time and historical time series.
|
| We don't know why some cycles are less intense, and the last few
| cycles have generally been on a downward trend (e.g.,
| https://en.wikipedia.org/wiki/Solar_cycle#Sunspots). So again, it
| is indeed quite interesting to see this high activity - if it
| holds up.
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(page generated 2022-06-23 23:00 UTC)