If you can't explain the 'pause', you can't explain the cause...
Monday, March 25, 2013
New paper finds the Sun controlled climate change of Asian continent over past 12,000 years
A paper published today in Global and Planetary Change reconstructs climate change during the past 12,000 years and finds the Sun has governed climate change of the Asian continent during the Holocene. According to the authors, "Spectral analysis of our results demonstrates periodic changes of 1500, 1000 and 500 years of relatively warm and cold intervals during the Holocene of Siberia. We presume that the 1000 and 500 year climatic cycles are driven by increased solar insolation reaching the Earth surface and amplified by other still controversial mechanisms." Solar amplification mechanisms include via ozone, clouds, and ocean oscillations. Related: The Physical Evidence of Earth's Unstoppable 1,500-Year Climate Cycle
A complete Holocene sequence of loess and buried soils has been studied in Siberia
Climatic cycles of 1000 and 500 years are revealed using petromagnetic parameters
Such periods correspond to variations in solar insolation and sun spot activity
Climatic cyclicity in the continental interior contains also oceanic cycle of 1500 years
We conducted a high-resolution study of a unique Holocene sequence of wind-blown sediments and buried soils in Southern Siberia, far from marine environment influences. This was accomplished in order to assess the difference between North Atlantic marine and in-land climate variations. Relative wind strength was determined by grain size analyses of different stratigraphic units. Petromagnetic measurements were performed to provide a proxy for the relative extent of pedogenesis. An age model for the sections was built using the radiocarbon dating method. The windy periods are associated with the absence of soil formation and relatively low values of frequency dependence of magnetic susceptibility (FD), which appeared to be a valuable quantitative marker of pedogenic activity. These events correspond to colder intervals which registered reduced solar modulation and sun spot number. Events, where wind strength was lower, are characterized by soil formation with high FD values. Spectral analysis of our results demonstrates periodic changes of 1500, 1000 and 500 years of relatively warm and cold intervals during the Holocene of Siberia. We presume that the 1000 and 500 year climatic cycles are driven by increased solar insolation reaching the Earth surface and amplified by other still controversial mechanisms. The 1500 year cycle associated with the North Atlantic circulation appears only in the Late Holocene. Three time periods — 8400–9300 years BP, 3600–5100 years BP, and the last ~ 250 years BP — correspond to both the highest sun spot number and the most developed soil horizons in the studied sections.