Scientists have discovered that events on the Sun can affect the Earth and pose a danger to orbiting satellites and astronauts, but could they also be a hazard to commercial airline flights?

It is indeed more dangerous to fly across the oceans when solar storms happen because transcontinental airlines flying in higher latitudes and altitudes are less protected by the Earth's changing magnetic field.

Every day the Earth is bombarded by cosmic rays and other solar energetic particles. These particles are electrically charged and travel at high speed. However, very few will actually get through and hit anyone. The particles that strike the Earth first have to get through the atmosphere, which is equivalent to a slab of concrete four meters thick. Many just end up interacting with nitrogen and oxygen atoms in the upper atmosphere. Since the Earth has a dipole magnetic field (should I say the Earth is like a big bar magnet?), and the electrically charged particles travel at different speed and angles, they get trapped and/or guided by the magnetic field and so find it easier to penetrate near the magnetic poles than at lower latitudes. Near the poles, magnetic field-lines are vertical, so a particle can zip on down as if along the vertical fibers of a carpet. At lower latitudes, magnetic field-lines are horizontal, so particles coming in vertically tend to bounce off or depending on their properties get trapped, unless they are powerful enough to bore their way through. Since the latitude is dependent on the magnetic field, it changes during exciting solar events and can extend quite far southward.

Using computer model and satellite data, scientists try to determine the latitude accurately and provide timely warning to the space station and the shuttle so that an astronaut is not caught outside at the wrong time. It would also apply to transcontinental air flights that utilize higher latitude, high altitude airspace. Expectant moms, or persons increasingly dependent on electronic devices for maintenance of their heartbeat, perhaps should not fly on some air routes on some days.

Our thanks this week to Dr. Barbara Giles. Dr. Giles is an astrophysicist working at the Laboratory for Extraterrestrial Physics of NASA/Goddard Space Flight Center. Her primary research areas are the transport, dynamics, and source of thermal charged particles that affect that the Earth's magnetic field. She is currently working in the Living with a Star program, which is part of Sun-Earth Connection.