High-resolution water isotope records from recent Greenland and Antarctic ice core projects

As the original measurement scheme in ice core science, water isotope records have always been a pillar of the paleoclimate community. In recent decades, improvements in analytical techniques have allowed for unprecedented resolution in water isotope records. For deep ice cores that once had 60,000 data points, we can now measure millions. Here, we provide updates on four recent high-resolution ice core records: WAIS Divide (WDC), South Pole (SPC), Renland Ice Cap (RECAP), and East Greenland (EGRIP). Each of these water isotope records has been obtained using laser absorption spectroscopy (LAS) coupled with continuous flow analysis (CFA). The on-going results of these projects are changing our view of the climate system by providing a viewpoint into the high-frequency portions of climate variability (ranging from decadal to sub-annual). For WDC, reconstructions and modeling results have been completed for 3-15 yr variability for the last 31 kyr, including a new type of abrupt (centennial scale) climate change arising from inter-hemispheric teleconnection mechanisms at ~16 ka. A WDC record of annual variability in the Holocene is also in the works, including a decomposition of the annual-cycle into summer and winter components. For SPC, interannual to decadal scale interpretations are possible into the last glacial period and are currently being investigated. For RECAP, annual reconstruction is possible for the last 2-3 thousand years, and decadal-scale variability may track with offshore sediment cores that suggest sea ice or altered ocean circulation plays a prominent role in the Holocene hydrologic cycle of east Greenland. Finally, EGRIP provides a unique high-frequency viewpoint into Dansgaard-Oeschger cycles, as well as other time periods spanning the last glacial-interglacial cycle. To date, the EGRIP record (>2 km) has been entirely analyzed on the Greenland Ice Sheet using a field deployable LAS-CFA system. These and other insights will be shared for these ice core records, part of a highly collaborative framework with support and leadership from many research groups.