The solar wind at the turn of the century
Abstract
Comparisons of geomagnetic activity and sunspot number over the past hundred years are studied with particular reference to the pattern of the minima from cycle to cycle. Values are given for the solar-cycle variations of yearly averages of sunspot number and aa index of geomagnetic activity for those cycles where the yearly mean aa index increases nearly linearly in time, and for the solar cycle minima of yearly means of the aa index. An empirical relationship between geomagnetic activity and the product of the square of the solar wind speed and the southward component of the interplanetary magnetic field is used to estimate the solar wind speed and/or magnetic field intensity in 1901.
- Publication:
-
Nature
- Pub Date:
- October 1978
- DOI:
- 10.1038/275626a0
- Bibcode:
- 1978Natur.275..626F
- Keywords:
-
- Geomagnetism;
- Solar Activity Effects;
- Solar Terrestrial Interactions;
- Solar Wind;
- Sunspot Cycle;
- Periodic Variations;
- Solar Corona;
- Solar Wind Velocity;
- Solar Physics;
- GEOMAGNETISM;
- SOLAR ACTIVITY EFFECTS;
- SOLAR TERRESTRIAL INTERACTIONS;
- SOLAR WIND;
- SUNSPOT CYCLE;
- PERIODIC VARIATIONS;
- SOLAR CORONA;
- SOLAR WIND VELOCITY