Climate evolution across the Mid-Brunhes transition

• Main Authors: Barth, Aaron M., Clark, Peter U., Bill, Nicholas S., He, Feng, Pisias, Nicklas G.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Rowan Digital Works 2018
• Subjects: Climate; Geology; Glaciology; ice core
• Online Access: https://rdw.rowan.edu/see_facpub/36; https://rdw.rowan.edu/cgi/viewcontent.cgi?article=1036&context=see_facpub

The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in the amplitude of the 100 kyr climate cycles of the past 800 000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO2 levels after the MBT, and benthic oxygen isotope (δ18O) records, which suggest that post-MBT interglaciations had higher sea levels and warmer temperatures than pre-MBT interglaciations. It remains unclear, however, whether the MBT was a globally synchronous phenomenon that included other components of the climate system. Here, we further characterize changes in the climate system across the MBT through statistical analyses of ice-core and δ18O records as well as sea-surface temperature, benthic carbon isotope, and dust accumulation records. Our results demonstrate that the MBT was a global event with a significant increase in climate variance in most components of the climate system assessed here. However, our results indicate that the onset of high-amplitude variability in temperature, atmospheric CO2, and sea level at ∼430 ka was preceded by changes in the carbon cycle, ice sheets, and monsoon strength during Marine Isotope Stage (MIS) 14 and MIS 13.