Solar Periodicity and Rainfall Patterns
Whilst most people accept interference to their mobile phones from periods of peak solar emissions, support for the idea that these emissions can affect our weather and climate patterns is currently at the margin.
This project researches the behaviour of the Sun and how its emissions follow patterns like vibrating guitar strings, where there are ~11 year (sunspot), ~22year (Hale), ~88 year (Gleissberg) and ~385 year cycles, that influence the southern oscillation index (and hence the likelihood of rainfall in eastern Australia).
There are five phases in the evolution of the Sun’s magnetic field within a sunspot cycle that can impact on the southern oscillation index (SOI). The drought phases seem to be intensified when the Sun’s South Pole becomes positive (the last time in 2001). Indeed, the whole process seems to be southern hemisphere-specific, particularly with the intensification of drought phases.
The SOI tracks the ~88 yr Gleissberg Cycle closely, such as, when the fluctuations of the 2000s are paired with the 1920s. This allows for predictions to be made of expected future rainfall patterns, where the rainfall from June 2007 to June 2008 has a high likelihood of being well above average (as was the case in 1924/25).
The ~385 year cycle which is expected to finish in 2020 can account for the extreme events, such as, the Federation Droughts at the beginning of the 20th century and the Maitland Floods of 1955. The behaviour of the Sun, as the engine that drives the Earths climate system, therefore is argued to be an essential ingredient in any robust modelling of global warming and climate change.
