Above is a plot of the hourly mean values for the Alibag observatory in India for the quietest day each month from November 1966 to February 1968. Quiet days were identified as having low Kp index values indicating minimal solar activity. Each vector component of the magnetic field (X=North, Y=East, Z=Down) is plotted separately in units of nT (nanotesla). The solid line in each figure is the value predicted by the Sq model. The mean and standard deviation of the difference between the observatory values and the model values are displayed above each plot. As illustrated in the plot, the Sq model follows the daily and seasonal variations quite well for this mid-latitude observatory.

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