Math help, CME on 03/24/2024

[Wade]

Can someone on here help me calculate the radiation dose received on a flight for Salt Lake City (SLC) to Nashville (BNA) on the afternoon of 03/24/2024. It was a 2:50 min flight at 37,000ft (FL370) and frankly I am completely freaked out. It departed at 1:50 Pm MDT (1950Z) and arrived in Nashville at 5:40 CDT (2240Z). 

[Newbie]

11 hours ago, Wade said:

Can someone on here help me calculate the radiation dose received on a flight for Salt Lake City (SLC) to Nashville (BNA) on the afternoon of 03/24/2024. It was a 2:50 min flight at 37,000ft (FL370) and frankly I am completely freaked out. It departed at 1:50 Pm MDT (1950Z) and arrived in Nashville at 5:40 CDT (2240Z). 

@Wade The link below might help you calculate exposure and provide some context for the results. It would be the equivalent of a dental X-ray.

Radiation exposure during a three hour flight in the US is generally considered very low and well within safe limits. Commercial aircraft are designed to shield passengers from cosmic radiation, and the doses received during flights are comparable to those encountered in the activities of daily life.

Additionally, regulatory agencies like the Federal Aviation Administration (FAA) monitor radiation levels to ensure passenger safety.

https://www.omnicalculator.com/everyday-life/flight-radiation

N.

[Philalethes]

12 hours ago, Wade said:

Can someone on here help me calculate the radiation dose received on a flight for Salt Lake City (SLC) to Nashville (BNA) on the afternoon of 03/24/2024. It was a 2:50 min flight at 37,000ft (FL370) and frankly I am completely freaked out. It departed at 1:50 Pm MDT (1950Z) and arrived in Nashville at 5:40 CDT (2240Z). 

See e.g. this paper where they consider much stronger proton events (two cases of S4, one GLE and one non-GLE) and also consider the exposure in the polar regions where it would be the greatest. They conclude that the additional radiation exposure is only roughly 50-65% higher than the ambient exposure during minimum, and that an estimate for a flight near the polar regions at 12 km of altitude (~40,000 ft) corresponds to a total dose of around 30 µSv, which is also roughly the estimate for a regular cross-country flight; at worst you were probably exposed to no more than an additional 15-20 µSv. As Newbie mentions above, this is around the radiation exposure from a dental X-ray, which is estimated to be around 5-10 µSv, so perhaps 4 dental X-rays at worst.

What I'm more confused about is why you'd be "completely freaked out" before you actually know whether there's really anything to worry about at all.

[hamateur 1953]

12 hours ago, Wade said:

Can someone on here help me calculate the radiation dose received on a flight for Salt Lake City (SLC) to Nashville (BNA) on the afternoon of 03/24/2024. It was a 2:50 min flight at 37,000ft (FL370) and frankly I am completely freaked out. It departed at 1:50 Pm MDT (1950Z) and arrived in Nashville at 5:40 CDT (2240Z). 

If you are concerned because of the increased particle radiation expressed on this site. The other posters above make very good points.  Our atmosphere provides very good protection from the bad stuff.  Over the pole flights may be delayed only as a consideration for the flight crews and pilots who are exposed on a daily basis. It really is nothing to be concerned about.  

[Philalethes]

3 minutes ago, hamateur 1953 said:

If you are concerned because of the increased particle radiation expressed on this site. The other posters above make very good points.  Our atmosphere provides very good protection from the bad stuff.  Over the pole flights may be delayed only as a consideration for the flight crews and pilots who are exposed on a daily basis. It really is nothing to be concerned about.  

There's always the "banana equivalent dose" of roughly 0.1 µSv per banana due to radioactive potassium, heh. In this case you'd be looking at an additional dose corresponding to at most 150-200 bananas at worst; I can easily go through that in a few weeks, and I haven't turned into a radioactive mutant blob just yet.

Also notable how just standing around will yield a natural background exposure of an estimated 0.27 µSv/h, almost 3 bananas worth. When considering this, you'll get the same radiation exposure from that flight (under the worst circumstances, this wasn't exactly an S4 either) as you would naturally from just living and going about your business for around 3-4 days.

[hamateur 1953]

4 hours ago, Philalethes said:

There's always the "banana equivalent dose" of roughly 0.1 µSv per banana due to radioactive potassium, heh. In this case you'd be looking at an additional dose corresponding to at most 150-200 bananas at worst; I can easily go through that in a few weeks, and I haven't turned into a radioactive mutant blob just yet.

Also notable how just standing around will yield a natural background exposure of an estimated 0.27 µSv/h, almost 3 bananas worth. When considering this, you'll get the same radiation exposure from that flight (under the worst circumstances, this wasn't exactly an S4 either) as you would naturally from just living and going about your business for around 3-4 days.

Good one @Philalethes! I forgot about potassium 40.   Hopefully this doesn’t offend the banana republics!  😋 Hopefully this is reassuring to @Wade  Cosmic rays as they were called when first discovered long ago are a fact of life here.  😋

Edited March 27 by hamateur 1953

[Newbie]

A SHARP REDUCTION IN COSMIC RAYS: Astronauts on the International Space Station got a break from their daily dose of cosmic rays on March 24th when radiation levels suddenly dropped more than 14%. What happened? A coronal mass ejection (CME) swept the radiation aside:

This is called a "Forbush decrease," named after American physicist Scott Forbush who studied cosmic rays in the early 20th century.  It happens when a CME sweeps past Earth and pushes galactic cosmic raysaway from our planet. Radiation from deep space that would normally pepper space stations, satellites, and Earth’s upper atmosphere is briefly wiped out.

In the graph, above, the Forbush decrease is shown as a downward spike in neutron counts recorded at the Sodankyla Geophysical Observatory in Oulu, Finland. Neutrons are a well-known proxy for cosmic rays. When cosmic rays strike Earth's upper atmosphere, they produce a spray of neutrons that reach the ground below. Sensors in Oulu count these "secondary cosmic rays" to monitor activity in space.

This week's Forbush decrease is the biggest of Solar Cycle 25 (so far), exceeding the previous record-holder on Nov. 3-4, 2021 when a potent Cannibal CMEdropped neutron counts by 11%.

This came directly from Spaceweather.com (hope Tony doesn’t mind).

This event was possibly after your flight but it shows that during a CME the radiation levels actually fall.

N. 

PS They probably don’t serve bananas inflight anymore…just in case 🤣

 

[hamateur 1953]

Outta likes. Y’all are just too cool for this kid. 🤣🤣

[Wade]

I appreciate you all taking the time to respond on this thread, to someone who knows nothing about this subject but finds it interesting. There were a couple of initial descriptions Sunday afte noon that described a hole, or gash, (or a myriad of phrases) being ripped in the magnetosphere by the inbound CME - That sounds pretty bad - a hole being ripped in the magnetosphere - which immediately made me wonder, if there was hole in it, how much proton (or other particle) radiation was getting through and to flight altitudes at that level. Then, I made another move; I went down the click bait rabbit hole. Then I started reading about Carrington Event level dosages being one offs of 20 - 50 mSv. Then I read on the HPS page that you can get up to 200 μSv/Hr during *some* solar events. Then I started looking at the radiation profiles for the Halloween 2003 storms which totally freaked me out when I saw what the dosages were at aviation altitudes across North America. Not knowing how any of this works I started wondering how this 'severe' event stacked up the Carrington and Halloween 2003 events. Pretty soon I was swirling around in my own anxiety storm over the whole thing, because my family was with me and I worried about their dosages far more than mine. 

Was this event on Sunday relatively small in terms of intensity compared to the 2003 and 1859 events? I immediately started making conservative calculations assuming the entire flight was at 37,000 (it obviously wasn't) at 200 μSv/Hr. Is there good reason to think the dosage was less than that? 

Thanks, 
Wade

[hamateur 1953]

I will flag @Newbie She is more capable than I am to give you a rough idea of the exposure you might have encountered on your flight. I’m glad you understood the stuff.  Your question shows good awareness of the typical measurements employed these days too. That is unusual and a good thing if you aren’t obsessive like I was thirty years ago. ( still am about some aspects of Spaceweather).  🤣🤣. C ya. @Wade  Mike.   I’m gonna tag @Philalethes @Calder and maybe @helios  All sharp guys btw. I think she may be busy today. Last but certainly not least @Archmonoth  😋

Edited March 28 by hamateur 1953
? On particles during a specific flight

[Parabolic]

58 minutes ago, Wade said:

I appreciate you all taking the time to respond on this thread, to someone who knows nothing about this subject but finds it interesting. There were a couple of initial descriptions Sunday afte noon that described a hole, or gash, (or a myriad of phrases) being ripped in the magnetosphere by the inbound CME - That sounds pretty bad - a hole being ripped in the magnetosphere - which immediately made me wonder, if there was hole in it, how much proton (or other particle) radiation was getting through and to flight altitudes at that level. Then, I made another move; I went down the click bait rabbit hole. Then I started reading about Carrington Event level dosages being one offs of 20 - 50 mSv. Then I read on the HPS page that you can get up to 200 μSv/Hr during *some* solar events. Then I started looking at the radiation profiles for the Halloween 2003 storms which totally freaked me out when I saw what the dosages were at aviation altitudes across North America. Not knowing how any of this works I started wondering how this 'severe' event stacked up the Carrington and Halloween 2003 events. Pretty soon I was swirling around in my own anxiety storm over the whole thing, because my family was with me and I worried about their dosages far more than mine. 

Was this event on Sunday relatively small in terms of intensity compared to the 2003 and 1859 events? I immediately started making conservative calculations assuming the entire flight was at 37,000 (it obviously wasn't) at 200 μSv/Hr. Is there good reason to think the dosage was less than that? 

Thanks, 
Wade

The magnetosphere is similar to an onion in terms of layers. It can't actually get punctured what so ever. What actually happens when a CME hits, or gets subjected to fast solar wind, is that a layer of that onion gets peeled back. The layers that peel back form our magnetotail and that structure releases ionized particles and other space junk. It never gets peeled completely back and it always returns to its original structure once conditions allow it to. 

[hamateur 1953]

On 3/27/2024 at 5:15 AM, Philalethes said:

See e.g. this paper where they consider much stronger proton events (two cases of S4, one GLE and one non-GLE) and also consider the exposure in the polar regions where it would be the greatest. They conclude that the additional radiation exposure is only roughly 50-65% higher than the ambient exposure during minimum, and that an estimate for a flight near the polar regions at 12 km of altitude (~40,000 ft) corresponds to a total dose of around 30 µSv, which is also roughly the estimate for a regular cross-country flight; at worst you were probably exposed to no more than an additional 15-20 µSv. As Newbie mentions above, this is around the radiation exposure from a dental X-ray, which is estimated to be around 5-10 µSv, so perhaps 4 dental X-rays at worst.

What I'm more confused about is why you'd be "completely freaked out" before you actually know whether there's really anything to worry about at all.

I will just chime in here @Philaletheswith a personal observation:  Most scientists or well-informed Drs know the difference between ionising radiation and light or radio frequency radiation. However I actually had to accompany an inspector from our FCC to calm the fears of this one guy who saw the Radio  Frequency Radiation warnings we encounter daily in rooftop HVAC work.   I gave a small class explaining that as long as ya don’t stare into the microwave feed horn and obey the signs, you should be fine.  Fear  is a tough thing to break through once it gets a foothold.  Only education with clear facts has any chance imho.  I should also add that the rest of our shop understood it well and appreciated the class, however I was obligated to take over the frightened individuals accounts cuz he either was really scared or just watched too many you tube videos. The FCC inspector and me  thought it was probably the latter.  That’s why I love this site as I do.  We all strive to be factual while having fun. And an opportunity to learn stuff as we go.  And  in a couple years  hopefully another 2003!!  😂

Edited March 29 by hamateur 1953
Typo

[helios]

6 hours ago, Wade said:

Was this event on Sunday relatively small in terms of intensity compared to the 2003 and 1859 events? I immediately started making conservative calculations assuming the entire flight was at 37,000 (it obviously wasn't) at 200 μSv/Hr. Is there good reason to think the dosage was less than that? 
 

The event was a lot less energetic than those of 2003.

But even 200 μSv/h would not be reason for concern. That would be 0.6 mSv in 3 hours.
The recommendation for cabin crew is to not exceed 20 mSv total dose in a year.
For German flight crew, for example, it's mandatory to monitor the dose and the values have to be reported. In average they receive 1.82 mSv/year.

The received dose depends a lot on geographic position and altitude. But it's very likely miniscule. If you still have concerns, you could contact the FAA, they can calculate the dose rate based on the parameters, at least the German federal office for aviation does that.

(And no, an airplane hull doesn't protect from cosmic rays)

[Philalethes]

8 hours ago, Wade said:

Was this event on Sunday relatively small in terms of intensity compared to the 2003 and 1859 events?

Relatively small indeed, like a breeze relative to a Category 5 hurricane. And even in 2003 the radiation was probably not that alarming. See e.g. this paper for some estimates of the radiation doses on airplanes during various GLEs (which occur during the most intense Solar particle events), and note how the level of radiation rarely increases by more than around 100% of the background radiation that was already present. Some events are more extreme, and it's not unreasonable for the Carrington Event to have been associated with the dose you mention, but these events are of course correspondingly rare too. And even in those cases it's highly unlikely to pose any significant health risks, as the thresholds have been set to err on the side of caution, but at those extremes there might be a tiny increase in e.g. cancer risk. I believe I've read somewhere that you'd need 50-100 mSv/yr for prolonged exposure or 10-20 mSv of acute exposure to have any detectable increase in cancer risk in the medical literature, which might be an outdated number at this point, but should give some idea of how small these doses really are, being barely at the threshold for what's medically detectable. For comparison, a CT scan yields a dose of around 10-15 mSv, and has also been shown to be associated with the same small increase in risk for certain cancers; if I remember correctly, on average something like 1 in 2000 people exposed to a dose of 20 mSv would develop a case of cancer that was actually attributable to that exposure. So such exposure during an event like the Carrington Event wouldn't be ideal, since it would be like getting 1-3 CT scans (using your provided estimate of 20-50 mSv) for zero good reason, but even then it's very unlikely to cause any health problems.

[Veggi]

4 hours ago, hamateur 1953 said:

  That’s why I love this site as I do.  We all strive to be factual while having fun. And an opportunity to learn stuff as we go.  And  in a couple years  hopefully another 2003!!  😂

This is why I spend so much time here too. Lurking and just reading the forums over the last 4ish months has helped me learn so much about these topics and im very thankful for the community and it's collective knowledge. Ps, hope Hagrid is doing well.

[hamateur 1953]

4 minutes ago, Veggi said:

This is why I spend so much time here too. Lurking and just reading the forums over the last 4ish months has helped me learn so much about these topics and im very thankful for the community and it's collective knowledge. Ps, hope Hagrid is doing well.

Yeah thanks. @Veggi  He would create his own account but likely would be moderated into obscurity shortly!! 😂😂 Mike 

[helios]

A question regarding the "Forbush decrease"

The explanation on wikipedia seems a bit generic and I find it difficult to get a more detailed explanation why this doesn't happen with all CMEs equally.
But I could imagine that the northward orientation of the Bz-field played a role, since the CME basically extends earths magnetic field. Maybe someone knows more about this.

 

 

 

Edited March 31 by helios

[Parabolic]

3 hours ago, helios said:

A question regarding the "Forbush decrease"

The explanation on wikipedia seems a bit generic and I find it difficult to get a more detailed explanation why this doesn't happen with all CMEs equally.
But I could imagine that the northward orientation of the Bz-field played a role, since the CME basically extends earths magnetic field. Maybe someone knows more about this.

 

 

 

Biggest factors I can remember are:

1. Size of CME.

2. CME speed.

3. Plasma density.

4. Volume & Pitch Angle of SEP's.

The size of the CME determines how much cosmic radiance gets swept out of the way. CME speed, plasma density, and volume of SEP's correlate, often you only get an abundance of SEP's with CME speeds 1 km/s or faster with tons of ejecta (plasma). I don't remember the specifics about SEP pitch angle but I think it's just the path separate groups of localized protons follow outward.

Magnetic configuration of CME and ambient solar wind do play a role but their interaction is extremely difficult to observe therefore the literature was sparse.

To put it simply, galactic-ray's are similar to dust in a room. You open a window and a breeze (CME) pushes the dust that's suspended in the air out. Once you close the window the dust accumulates again from various sources.

[hamateur 1953]

8 hours ago, Parabolic said:

Biggest factors I can remember are:

1. Size of CME.

2. CME speed.

3. Plasma density.

4. Volume & Pitch Angle of SEP's.

The size of the CME determines how much cosmic radiance gets swept out of the way. CME speed, plasma density, and volume of SEP's correlate, often you only get an abundance of SEP's with CME speeds 1 km/s or faster with tons of ejecta (plasma). I don't remember the specifics about SEP pitch angle but I think it's just the path separate groups of localized protons follow outward.

Magnetic configuration of CME and ambient solar wind do play a role but their interaction is extremely difficult to observe therefore the literature was sparse.

To put it simply, galactic-ray's are similar to dust in a room. You open a window and a breeze (CME) pushes the dust that's suspended in the air out. Once you close the window the dust accumulates again from various sources.

There is another factor particularly with multiple CMEs.  If a prior CME or more has “ swept up” or cleared the way for its brothers the subsequent CMEs will have an easier time plowing their way to our magnetosphere.  This was evidently a big factor with the 14.5 hour travel time of the Aug 4 1972  event.  So far the quickest we have on record.  We would like another one with a Southern BZ this cycle before or after solar max, either way is cool with me. 

[Parabolic]

15 hours ago, hamateur 1953 said:

There is another factor particularly with multiple CMEs.  If a prior CME or more has “ swept up” or cleared the way for its brothers the subsequent CMEs will have an easier time plowing their way to our magnetosphere.  This was evidently a big factor with the 14.5 hour travel time of the Aug 4 1972  event.  So far the quickest we have on record.  We would like another one with a Southern BZ this cycle before or after solar max, either way is cool with me. 

Yes, thanks for including that as well! With my past fixation on modeling the effects of the 1972 event along with the 2003 Halloween event, I'm surprised I forgot about the possible effects of multiple CME's. I think Tamitha Skov even briefly mentions those two events and their effects on galactic-rays and the neutron monitor data in one of her mini-courses. 

Edited April 1 by Parabolic

[hamateur 1953]

She does indeed @Parabolic  there is a group that regularly launches telemetry containing balloons  from an area in NE California.  In addition to the neutron monitoring done by Oulu and in Japan somewhere.  I think they also sell stuff on SW.Com to help fund this project. Assuming that it’s the same group, of course.  

Edited April 1 by hamateur 1953
Luft Balloons