STATISTICAL INFERENCE. “The polarity of the ICME structure shows a statistical dependence on the solar cycle: the preferred leading polarity rotating from south to north is observed during the rising phase of odd-numbered solar cycles, while the opposite polarity is observed during the rising phase of even-numbered cycles.” (ICME = interplanetary magnetic cloud)
https://link.springer.com/article/10.12942/lrsp-2007-1