South Atlantic Anomaly: Are Cosmic Rays High in Flights to Brazil?

The South Atlantic Anomaly is observed on the ISS space station. It describes a weak point in the Earth’s magnetic field. That would lead to an increase in cosmic rays over the South Atlantic. The reason: As the German space agency DLR explains, the axis of the magnetic field does not run exactly through the center of the Earth.

It is slightly offset and tilted from the Earth’s axis of rotation. Therefore, the radiation belts around the Earth are closer to the surface in the Atlantic Ocean from the Brazilian coast. In this region, radiation exposure has increased in low Earth orbit. For example, it can be felt at an altitude of about 400 kilometers on the International Space Station (ISS).

Lots of measurements on board

But what about the altitude at which passenger planes normally fly? Two DLR scientists and one DLR scientist studied it on a Lufthansa Airbus A350-900 in March and April 2021. The DLR called the investigation Mission Atlantic Kiss.

Flight path through anomaly. Image: DLR

Using different instruments, they analyzed different components of the radiation field. For example, instruments to measure gamma rays include a 40-kilogram neutron probe. Because the instrument is sensitive, the researchers had to strap it to a row of seats at the plane’s center of gravity, where vibrations and turbulence are typically lower.

No sign of excessive radiation

According to the DLR, four semiconductor detectors registered the charged particles, while two tissue-equivalent proportional counters measured the radiation absorbed in very thin tissue. The conclusion was clear. And pleases.

The investigation was conducted. Picture. TLR

“Our measurements do not indicate an additional significant contribution to the radiation field at flying altitudes in the geographic region of the South Atlantic Anomaly,” says Matthias Meyer, head of the Atlantic Kiss mission. “Fears of high-altitude radiation exposure in this region are scientifically unfounded.” Earth’s atmosphere effectively shields it from cosmic radiation.

Lufthansa special flight

The measurements took place on a Lufthansa special flight. An Airbus A350-900 flew from Hamburg to the Falkland Islands in March 2021 – the second of two special flights and the longest non-stop flight ever by a German airline. In addition to the DLR crew, a crew of 40 took the research vessel Polarstern off the Forkland Islands and returned it across the Atlantic to Germany.