A pictorial comparison of coronal holes, Solar wind streams, and geomagnetic activity

Each of the figures is presented as a sequence of 27-day Bartels rotations with coronal hole information on the leftmost panel, wind speed on the second, the geomagnetic A_p index on the third and the F_10.7 solar flux on the rightmost panel. The bottom panel gives the sunspot number and locates the observed period in the Solar cycle. Each of the figures spans a time period of three years.

The yellow blocks in the left panel refer to coronal holes associated with positive (i.e. directed out of the Sun) polarity, blue blocks refer to negative polarity and the green blocks to a mixed polarity.

In the second panel, the colour code refers to the daily averaged Solar wind speed, from low (purple/blue) to high (yellow/red). The blocks are slanted with respect to the daily averaged z-component of the interplanetary field (GSM-coordinates). Blocks slanted to the upper right indicate a positive z-component, to the upper left negative polarity, not slanted mixed polarity.

The colour code in the third panel refers to the geomagnetic A_p index. The slanting is the same as in the previous panel.

The rightmost panel gives the F_10.7 radio flux for the first day of each Bartels rotation.

1970-1972 (PostScript version)

1973-1975 (PostScript version)

1976-1978 (PostScript version)

1979-1981 (PostScript version)

1982-1984 (PostScript version)

1985-1987 (PostScript version)

1988-1990 (PostScript version)

1991-1993 (PostScript version)

1994-1996 (PostScript version)

References

Sheeley, N. R. Jr., J. R. Asbridge, S. J. Bame, and J. W. Harvey: A pictorial comparison of interplanetary magnetic field polarity, solar wind speed, and geomagnetic disturbance index during the sunspot cycle, October 1976.