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{"Abstract":["Two parallel surface-to-bedrock ice cores (DEN-13A and DEN-13B) were drilled from the Begguya summit plateau in Denali National Park, Alaska (62.93 N 151.083 W, 3912 m asl; also known as Mount Hunter), during the summer of 2013. The summit of Begguya has a high accumulation rate and low melt rate, making it an ideal site to recover intact paleoclimate records. DEN-13A and DEN-13B, which reach depths of ~210 meters, respectively, cover at least 10,000 years (Fang et al., 2023). Shallow cores were drilled in the summers of 2019 (DEN-19A; 50 meters) and 2022 (DEN-22A; 20 meters) extend the paleoclimate record at this site through 2022. Together, these four ice cores are commonly referred to as the Denali Ice Core record or the Begguya summit plateau ice core record. A robust chronology has been developed using a combination of techniques including annual layer counting, sulfate peaks (volcanics), radiocarbon dating and the 1963 atmospheric nuclear weapons testing horizon (Fang et al., 2023). Here, we report aqueous ICP-MS elemental concentrations and Pb isotope ratio data for the top ~1,200 years (800 to 2022 CE) of the Begguya summit plateau ice core record."],"Other":["Fang, L., Jenk, T. M., Winski, D. A., Kreutz, K. J., Brooks, H. L., Erwin, E., Osterberg, E. C., Campbell, S. W., Wake, C. P., Schwikowski, M, (2023), "Early Holocene ice on the Begguya plateau (Mt. Hunter, Alaska) revealed by ice core 14 C age constraints." The Cryosphere, 17(9):4007-4020; Osterberg, E. C., Winski, D. A., Kreutz, K. J., Wake, C. P., Ferris, D. G., Campbell, S. W., Introne, D. S., Handley, M. J., Birkel, S. D., (2017), "The 1200 year composite ice core record of Aleutian Low intensification." Geophysical Research Letters, 44(14):7447-7454."]} 

High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979–2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.