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WhySoTough
10th Oct 2018, 14:20
Hello,

Hope everyone is having a nice day/week.
I know that the airline I fly for tries to spread the Polar routes, or high latitude routes at (70N) etc equally among all pilots. They try to monitor the exposure, but surely enough not to the extent where their primary concern is us over operations.
I was simply wondering if flying at southern latitudes of S20, inbound to Australia for example, has the same effect in terms of radiation?

Thanks for your input!

wiggy
10th Oct 2018, 14:53
You’ve asked about UV in the title then asked about “radiation” in the text...which is a bit confusing...

1. You are more exposed to ionising “radiation”, as in the sort of stuff the sun chucks out in Solar Flares and The Cosmic rays from deep space at high latitudes (specifically high magnetic latitudes), I suspect that’s why your company is metering your flights at high latitude...but that’s a different “animal” to UV.

2. UV is the electromagnetic radiation (with a wavelength just below that which is visible to the naked eye) ..that produces sunburn and your exposure to that is more dependant on the elevation of the sun, any cloud cover, thickness of the ozone layer, windscreen thickness and materials..probably plus lots more

To answer your question about Oz and being 20 south... well at those latitudes you are well away from the thin bit of the earths’s magnetic field around the poles and so are well protected from ionising radiation, so I wouldn’t be unduly worried about ionising radiation in flight...OTOH you are near the equator and I would however be more tad a bit cautious about the UV at ground level, e.g walking around without sunblock or any other form of UV protection whilst on a slip in that part of the world.

pattern_is_full
10th Oct 2018, 17:30
Incoming solar radiation (ionized particles) doesn't recognize the human conventions of "north" or "south" - thus will be the same at 70N as at 70S. Although it may depend a bit on the season (local "summer" or "winter" months).

The main issue with the polar regions is that the ionized particles tend to follow the lines of Earth's magnetic field. They are focused like a flock of ICBM's into trajectories aimed into the polar regions, thus producing the Auroras (Australis and Borealis) - which are ionizing particles hitting the atmosphere molecules and making them glow (oxygen, red or green; nitrogen, blue or crimson). Thus the amount (and any risk) will be higher at 70N/70S than at 20N/20S.

If you are flying in the polar regions, and see the Aurora right overhead - you are in the "line of fire." :eek:

AtoBsafely
10th Oct 2018, 18:08
There was a “hole” in the ozone layer, which allowed more UV through, but it has closed up in the years since CFCs were banned. It was located over Antarctica, at latitudes of more than 60S. Not an issue, even if you are flying to Hobart!

ShotOne
10th Oct 2018, 18:42
Our company uses Globalog which give a statistically based dosage figure based on which routes you've flown and when. Sometimes, not so often, we have pilots taken off duties. This mostly arises after a rash of UK-West Coast USA flts.

As for UV, my one piece of advice is invest in a good quality pair of wrap-around sunglasses -and wear them!

Check Airman
10th Oct 2018, 20:16
As for UV, my one piece of advice is invest in a good quality pair of wrap-around sunglasses -and wear them!

...or fly at night;)

ion_berkley
10th Oct 2018, 20:18
UV has already been well covered above. Exposure to ionizing radiation is a function of:
1) Altitude (because the atmosphere attenuates the secondary radiations which cause this exposure, the primary radiation having had nuclear interactions with the upper atmosphere well above aviation altitudes)
2) Magnetic Latitude (because as you near the magnetic poles the magnetic field lines are increasingly parallel to the trajectories of the energetic particles and impede their progress less)
3) Solar cycle (because, perhaps a little counter intuitively, the primary source of this harmful radiation is galactic cosmic rays, and magnetic fields created by increased solar plasma help deflect these from Earth)
3a) ...the caveat!.. however certain solar events that can send streams of energetic particles towards Earth can cause localized increases.

Now the interesting trivia part....there is a region in the Southern hemisphere that behaves differently *BUT* it only affects altitudes 200km+ (so satellites, not aircraft)
https://en.wikipedia.org/wiki/South_Atlantic_Anomaly

Gauges and Dials
10th Oct 2018, 20:33
...or fly at night;)

It is largely due to concerns about ionizing radiation, that NASA has announced that all contemplated future manned missions to the Sun will be flown entirely at night.

tdracer
11th Oct 2018, 01:35
UV is of minimal concern inside an aircraft - the fuselage will completely block UV (either aluminum or composite), and the aircraft windows filter out well over 90% of UV.

FullWings
11th Oct 2018, 13:38
UV is of minimal concern inside an aircraft - the fuselage will completely block UV (either aluminum or composite), and the aircraft windows filter out well over 90% of UV.
10% of the incident UVA/B when you’re at 40,000'+ plus is very significant. Even 1% would be a worry in direct sunlight...