NOAA / Space Weather Prediction Center

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Continental United States Users (Geomagnetic Middle Latitudes)

The behavior of the Earth's magnetic field is the most significant factor for GPS operations in this locale. Select the Planetary K-Index Plot to see if the magnetic field has been disturbed, as denoted by red bars, during the past 72 hours.

Canada/Alaska Area Users (Geomagnetic High Latitudes)

Particle precipitation in the auroral zone results in increased scintillation in the ionosphere. The auroral oval is usually near the areas of increased scintillation. GPS operations may be hampered when the signals from the spacecraft to the ground pass through the auroral oval. The NOAA/TIROS Hemispheric Power Input Plotshows the likely location of the auroral oval, using recent data. The auroral oval will move equatorward when geomagnetic activity increases.

Large quantities of solar energetic particles can also cause scintillation at high latitudes. Check the Proton Flux Plot to determine if the proton environment is enhanced. If the red trace (E >10 MeV) exceeds 1.0E+1, conditions may exist that are adverse for GPS users.

Forecasts of Solar and Geophysical activity for the next few days are sometimes helpful in planning future GPS operations at both middle and high latitudes. The Joint USAF/NOAA Report of Solar and Geophysical Activity contains information on geomagnetic activity (parts II, V, and VI), and solar energetic particles (part II).

* Link to a non U.S. government site.

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Updated: October 1, 2007