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Solar Radio Flux Derivation and Representation

Copyright WDC for STP at RAL.

Observed daily values are measured at the observatory at local noon (1700UT Ottawa, 2000UT Penticton). They are given in solar flux units (1 sfu = 10-22.m-2.Hz-1).

Adjusted values are calculated from the observed values so as to remove the variaton in flux observed due to the varying distance between the sun and the earth throughout the year. They are scaled to an average sun - earth distance of 1 AU.

Monthly means are calculated for observed and adjusted data from the daily values.

Smoothed values are calculated as a 12 month running mean of the monthly mean values. That is the smoothed flux for a given month is the average of all the monthly means from -6 to +6 months around that month.