Dosimetre på vei inn igjen for de som flyr høyt? - Curt Lewis

Space radiation with extra punch a hazard for high flying aircraft

Solar winds sending charged particles to Earth in 'clouds' can double normal exposure to radiation on long-haul flights

A Boeing jet. Commercial aviation safety can benefit from real-time dose measurements, say researchers.

Space weather is not usually noticeable on Earth, but research suggests that it may produce blasts of radiation that do affect air travellers. Fortunately, this occurs in localised "clouds" which aircraft could avoid, just as they can avoid clouds of volcanic dust.

The research, published in the journal Space Weather, is connected to the Nasa-funded Automated Radiation Measurements for Aerospace Safety (Armas) project. Scientists already knew that there was more radiation at higher altitudes; a long-haul flight can give you the same exposure as a chest X-ray. However, it was a surprise when, during six of 265 test flights, radiation levels shot up far beyond the normal levels.

Data relating to a flight passing through a radiation cloud.

The surges seem to come from the Van Allen radiation belts, according to the research, led by W Kent Tobiska. These belts trap charged particles, but the "solar wind", the stream of particles from the sun, sometimes blows so powerfully that the charged particles are dislodged. They are channelled towards Earth in the forms of stray beams of radiation. The beams cannot penetrate all the way to sea level, but produce increased radiation levels at high altitudes.

Tobiska described the areas where there was increased radiation as "clouds". While the radiation was not extreme here, it might double the normal exposure you might expect flying at certain altitudes and latitudes. The Armas programme should be able to help scientists develop technology to map these events as they occur.

This discovery could prompt airlines to fly around the clouds or at a lower altitude to reduce the radiation hazard, which might especially affect aircrew and other frequent flyers.