The records of δ18 O and dust from BC1 can be related to long-term shifts in atmospheric circulation, which are expressed by the two primary modes of Northern Hemisphere circulation: the Aleutian Low (AL) and the Arctic Oscillation (AO). 315, which corresponds with the end of the core.
By using a time-depth model, the timeline can be extended to A.D. Counting of annual layers was possible from A.D.
The timescale for the 2003 Quelccaya Summit Core is based upon multiple lines of evidence, including annual layer counting based on peaks in dust, a well-defined annual cycle in δ18 O, the identification of ash layers in the ice core corresponding to historic volcanic eruptions, and comparisons of the Quelccaya core with other regional ice cores. 760 to 777 (according to the BC1 timeline) as the likely timing of the White River Ash, an important regional chronostratigraphic marker. Additionally, this study pinpoints the period A.D. The timescale for BC1 is well constrained during the last 1,000 years by annual layering, the identification of the 1963 β-peak, the 1912 eruption of Katmai, and the 1783 eruption of Laki. This thesis outlines the development of the timescales, the calibration of the ice-climate relationships, and the possible linkages between the Quelccaya Summit Ice Core and the Bona Churchill Ice Core, with different modes of decadal and interannual climate variability during the last 1,000 years.
