Long term magnetic review and forecast

27 day forecast

The parameter used for forecasting magnetic activity in the 27 day forecast is a daily index. It is known as DRX and is the average of the hourly ranges (maximum minus minimum during each hour) in the X (northward) component of the magnetic field intensity for a day (the UT or GMT day).

Magnetic activity review

The parameter used for the 30 day magnetic activity review is a daily index. It is known as DRX and is the average of the hourly ranges (maximum minus minimum during each hour) in the X (northward) component of the magnetic field intensity for a day (the UT or GMT day), ie DRX for the zone is the mean of 24 values.

Description

Long Term DRX Activity Levels (nT)
Zone Quiet Unsettled Active Stormy
Polar Cap 0 - 40 40 - 100 100 - 160 160+
Auroral Zone 0 - 60 60 - 160 160 - 240 240+
Sub-Auroral Zone 0 - 20 20 - 40 40 - 80 80+
Map of the Polar Cap, Auroral Zone, and Sub-Auroral over Canada.

For each of the three major zones (subauroral, auroral, polar cap), the range of activity is divided into four classifications: quiet, unsettled, active, storm. The actual parameter used for reporting and forecasting magnetic activity is a daily index. It is known as DRX and is the average of the hourly ranges (maximum minus minimum during each hour) in the X (northward) component of the magnetic field intensity for a day (the UT or GMT day), ie DRX for the zone is the mean of 24 values. Because this averaging process has the effect of smoothing (filtering) the more rapid fluctuations in the field, the qualitative descriptors are defined rather differently than for the short-term forecasts. Units are nanoteslas (nT).

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