Editing Space weather (section)

===Humans in commercial aviation ===
The magnetosphere guides cosmic ray and solar energetic particles to polar latitudes, while high-energy charged particles enter the mesosphere, stratosphere, and troposphere. These energetic particles at the top of the atmosphere shatter atmospheric atoms and molecules, creating harmful lower-energy particles that penetrate deep into the atmosphere and create measurable radiation. All aircraft flying above 8&nbsp;km (26,200 feet) altitude are exposed to these particles. The dose exposure is greater in polar regions than at midlatitude and equatorial regions. Many commercial aircraft fly over the polar region. When a space weather event causes radiation exposure to exceed the safe level set by aviation authorities,<ref>FAA Advisory Circular 120-52, March 5, 1990, Radiation exposure of air carrier crew members</ref> the aircraft's flight path is diverted.

Measurements of the radiation environment at commercial aircraft altitudes above 8&nbsp;km (26,000&nbsp;ft) have historically been done by instruments that record the data on board where the data are then processed later on the ground. However, a system of real-time radiation measurements on-board aircraft has been developed through the NASA Automated Radiation Measurements for Aerospace Safety (ARMAS) program.<ref>W. K., Tobiska, D. Bouwer, D. Smart, M. Shea, J. Bailey, L. Didkovsky, K. Judge, H. Garrett, W. Atwell, B. Gersey, R. Wilkins, D. Rice, R. Schunk, D. Bell, C. Mertens, X. Xu, M. Wiltberger, S. Wiley, E. Teets, B. Jones, S. Hong, K. Yoon, Global real-time dose measurements using the Automated Radiation Measurements for Aerospace Safety (ARMAS) system, Space Weather, 14, 1053-1080 (2016).</ref> [http://sol.spacenvironment.net/~ARMAS/ ARMAS] has flown hundreds of flights since 2013, mostly on research aircraft, and sent the data to the ground through Iridium satellite links. The eventual goal of these types of measurements is to data assimilate them into physics-based global radiation models, e.g., NASA's Nowcast of Atmospheric Ionizing Radiation System ([http://sol.spacenvironment.net/~nairas/index.html NAIRAS]), so as to provide the weather of the radiation environment rather than the climatology.