cosmic radiation change with altitude
I guess you still think the world is flat.
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I used to be involved on the periphery of research into this.
Radiation increases with altitude though above some 40,000ft the rate of increase reduces (at least for levels where civillian aircraft fly). At a constant altitude it increases from the equator towards the magnetic poles because a) the particles are attracted to the poles and are therefore more concentrated in that region and b) radiation is attenuated by the atmosphere; the atmosphere being deeper at the equator, you have more atmosphere above you and you are therefore more protected.
A trace of the measured radiation on a flight from the UK to Singapore showed a steep increase as the aircraft climbed to its initial cruising level and then a steady reduction as the aircraft progressed south, punctuated by two distinct upticks as higher cruising levels were attained. The level of radiation at TOD Singapore was very significantly lower that at TOC UK even though the aircraft was 8,000ft higher.
It's not much but I hope it helps...
MT
Radiation increases with altitude though above some 40,000ft the rate of increase reduces (at least for levels where civillian aircraft fly). At a constant altitude it increases from the equator towards the magnetic poles because a) the particles are attracted to the poles and are therefore more concentrated in that region and b) radiation is attenuated by the atmosphere; the atmosphere being deeper at the equator, you have more atmosphere above you and you are therefore more protected.
A trace of the measured radiation on a flight from the UK to Singapore showed a steep increase as the aircraft climbed to its initial cruising level and then a steady reduction as the aircraft progressed south, punctuated by two distinct upticks as higher cruising levels were attained. The level of radiation at TOD Singapore was very significantly lower that at TOC UK even though the aircraft was 8,000ft higher.
It's not much but I hope it helps...
MT
Last edited by Mach Tuck; 10th Nov 2011 at 13:28. Reason: Spelling
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You can compare flights between cities pairs using the CARI-6 program.
FAA Civil Aeromedical Institute - CARI
I researched three long haul city pairs between the U.S. to LHR vs. Tokyo. Radiation on the LHR flights were slightly higher even though the flights were shorter. With shorter flights a greater percentage of the flight is spent in the climb or descent vs. a longer flight. The shorter distance is flown, on average, at higher altitudes, so the net impact between the different city pairs is very small.
FAA Civil Aeromedical Institute - CARI
I researched three long haul city pairs between the U.S. to LHR vs. Tokyo. Radiation on the LHR flights were slightly higher even though the flights were shorter. With shorter flights a greater percentage of the flight is spent in the climb or descent vs. a longer flight. The shorter distance is flown, on average, at higher altitudes, so the net impact between the different city pairs is very small.
Last edited by misd-agin; 10th Nov 2011 at 14:09. Reason: added text for clarity
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Chart doesn't go high enough--what about FL410-FL470. I'm figuring' that the lowered risk of mid-air and being on top of a lot of weather compensates the odds.
Here is the complete chart..
Radiation increases DRAMATICALLY with increasing altitude! ( concorde.. )
that's why in the jar ops it's compulsory to carry radiation measuring equipment onboard if you fly very high
(b) 1. an operator shall not operate an aeroplane above 15 000 m (49 000 ft) unless the equipment specified in
OPS 1.680(a)(1) is serviceable, or the procedure prescribed in OPS 1.680(a)(2) is complied with.
2. the commander or the pilot to whom conduct of the flight has been delegated shall initiate a descent as soon as
practicable when the limit values of cosmic radiation dose rate specified in the Operations Manual are exceeded.
OPS 1.680(a)(1) is serviceable, or the procedure prescribed in OPS 1.680(a)(2) is complied with.
2. the commander or the pilot to whom conduct of the flight has been delegated shall initiate a descent as soon as
practicable when the limit values of cosmic radiation dose rate specified in the Operations Manual are exceeded.
ps: everytime I go fly I chk this:
Space Weather Warnings Currently in Effect
http://www.swpc.noaa.gov/rt_plots/Proton.gif
On-line SWPC Weekly Publication in Adobe Acrobat(R) format
