Modelling solar forcing and the magnetic field signature on Atmosphere-Ocean systems over the past 15,000 years: Evidence from fixed inter-tidal biological indicators of the southern hemisphere

Category Environmetal Geology
Group GSI.IR
Location International Geological Congress,oslo 2008
Author Baker, Robert
Holding Date 17 September 2008

There are a number of quasi-periodic event horizons that can be identified within Holocene and late Pleistocene climatic proxies (including fixed inter-tidal biological indicators- FIBIs) that appear to be multiples of a ~ 1540 yr cycle. This period was first discerned from the Greenland ice core record over the past 90,000 yr. For example, the rise of sea level to the present at ~6880 yr and its rapid fall from ~2m to ~1m higher than present, at 3760 yr BP, is twice this period. The period between the oscillation at the end of the Younger Dryas (~11560 yr) and the fluctuation at the beginning of the early Holocene at ~8440 yr is also approximately ~3080 yr apart.
Further, the commencement of the ’Little Ice Age’ at 1310 AD and the Bolling-Allerod oscillation (~14,640 yr BP) are also part of this period. What is also interesting is that the 1540 yr period, the ~10.6 yr average sunspot period and the average solar rotation of ~26.8 days are in a ratio of ~145. Further, within the 1560 yr period, there are four phases of ~418 yr with sub-harmonics of solar cycles ~121, 88, 88, 121 yrs (termed Gleissberg Cycles). A mathematical model of time similarity of the Sun’s magnetic field defines the solar emission ’signature’ of these decadinal to millennial harmonics. The southern oscillation index (associated El Nina/ La Nino events) is sensitive to a Gleissberg harmonic of UV radiation and cloud formation and, as such, the longer term 1540 yr solar cycles could be part of a millennial fluctuation in the Sun’s magnetic field and the consequent impact on cloud formation and mega-El Niño’s.
This could explain the rapid rise and fall of sea-levels and the changes in sea surface temperatures with a 1500 year periodicity that the invasion and disappearance of tropical and temperate FIBI species suggest, in Australia, South America and Asia. The rapid fall of sea-levels from ~2m to ~1m and the cooling of sea surface temperatures by ~4°C in Australia after 3760 yr BP could be the expected event horizon at the beginning of a mega- El Niño phase over the Pacific from a periodic millennial shift in the Sun’s magnetic field.