High-resolution analyses of an early Holocene climate event may imply decreased solar forcing as an important climate trigger
Abstract
Early Holocene lacustrine, tree-ring, ice-core, and marine records reveal that the Northern Hemisphere underwent a short cooling event at 10300 calendar yr B.P. (9100 14C yr B.P.). The records were compared on a common high-resolution time scale and show that the event lasted less than 200 yr, with a cooling peak of 50 yr, and the event coincides with a distinct Holocene thermohaline disturbance recognized in the North Atlantic Ocean. In spite of well- known freshwater forcings at the time of the event, the negligible difference between the modeled Δ14C record, based on the GISP2 (Greenland Ice Sheet Project 2) 10Be data, and the measured values, does not allow for detectable Δ14C changes related to global ocean ventilation. We can, however, show that the onset of the cooling coincides with the onset of one of the largest Holocene 10Be flux peaks. This finding may imply that the climate system is more sensitive to solar-related changes than previously thought and that such changes may be an important underlying mechanism for sub-Milankovitch climate variability.
- Publication:
-
Geology
- Pub Date:
- December 2001
- DOI:
- 10.1130/0091-7613(2001)029<1107:HRAOAE>2.0.CO;2
- Bibcode:
- 2001Geo....29.1107B