scope:

GENERAL

From an operations perspective, space weather events occur when the Sun causes disruptions to aviation communications, navigation and surveillance systems, and elevates radiation dose levels at flight altitudes. Space weather events may occur on short time scales, with the effects occurring from almost instantaneously to over a few days.

From a broader perspective, the World Meteorological Organization (WMO) defines space weather to be "The physical and phenomenological state of the natural space environment, including the Sun and the interplanetary and planetary environments." This more comprehensive definition cuts a broader band across the system to include the slowly varying galactic cosmic rays (GCR) coming from outside the heliosphere, as well as the repetitive high-speed solar wind streams from voids in the solar corona. In summary, not all space weather stems from eruptions but also from variations in the flow of charged particles, photons, and magnetic field.

Space weather forecasts for international air navigation address particular types of disturbances, i.e. solar radiation, geomagnetic and ionospheric storms, and solar flares. In addition, predictions of the slowly varying elements (i.e. GCR and high-speed stream-induced geomagnetic storms) are also produced. These forecasts enable operators the opportunity to be situationally aware and to formulate alternative plans should the impending conditions be of a magnitude and a type that could disrupt normal operations.

The objective of this manual is to enable operators to make informed decisions when space weather impacts occur. A proper balance between operationally relevant information and scientific completeness is sought. In many areas, more scientific rigor and detail could be brought forward but it would not enhance this manual's utility to the aviation community. A more in-depth explanation of the science underpinning the field of space weather science can be found in Appendix 2.