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Keeping aircraft safe

Keeping aircraft safe during geomagnetic storms

An image of the Sun with orange flares.

A solar flare erupts on the Sun's northeastern hemisphere at 3:49 UT on January 23, 2012. (Photo courtesy NASA.)

When a geomagnetic storm blasted Earth on January 24, commercial airlines redirected a handful of flights were originally routed to fly over the North Pole. This was necessary to avoid potential communications lapses and protect crews and passengers from excessive radiation at high latitudes.

Behind the scenes, NCAR scientists play a role in safety precautions such as these. Solar physicists Michael Wiltberger and Stanley Solomon are helping develop a tool for NAIRAS (Nowcast of Atmospheric Ionizing Radiation System), a NASA-funded computer model that provides global, real-time predictions of harmful atmospheric radiation levels at altitudes where commercial airlines fly. The system is currently a prototype model, but once fully developed it will help protect airline crews from solar radiation, especially during geomagnetic storms.

Wiltberger and Solomon are providing NAIRAS with numerical simulations of the magnetosphere (Earth’s magnetic field) for the model's next round of development; currently, the model uses simulations that estimate future behavior based on data from past episodes. Through testing and analysis, they’ll determine if the numerical simulations better predict radiation at high latitudes and altitudes during geomagnetic storms. They’re also looking at the cost-benefit ratio between the extra computing power required to run numerical models and the potential improvements they offer.

Geomagnetic storms occur when eruptions on the Sun, called coronal mass ejections, send streams of charged particles into Earth's atmosphere. In addition to causing the aurora borealis, the storms can affect satellite communications, navigation, the power grid, and more. The January 24 storm was the most powerful of its kind since 2005.