Successive Oceanic and Solar Forcing Indicated by Younger Dryas and Early Holocene Climatic Oscillations in the Jura

Abstract

The recent extension of (1) the residual Δ 14C curve back to 11,400 cal yr B.P. and (2) the lake-level reconstruction in the Jura back to ca. 13,500 cal yr B.P. offers the opportunity of testing by proxy data the relationships between climate, atmospheric 14C, the sun, and the ocean recently suggested from the atmospheric 14C record. The climatic significance of the Jura record is supported by correlations with climatic oscillations reconstructed in the Alps from glaciers and timberline movements. Correspondence between the 14C and paleoclimatic record from the Jura suggests a working hypothesis: two intervals within the Holocene can be distinguished in the middle latitudes of western and central Europe. An early Holocene period shows abrupt climatic oscillations linked to ocean forcing. Major colder climate phases developed between ca. 9000 and 8800, and between ca. 8000 and 7000 cal yr B.C. that coincide with higher Δ 14C values. After 6000 cal yr B.C., a second period is characterized by smoother multicentury climatic oscillations linked to solar forcing.