ALBERT

Description: Kr and Xe isotope measurements (raw and corrected), sample information, well information, and inverse model output for groundwater samples from 36 wells across California spanning three regions: 1) San Diego, 2) Fresno, 3) Mojave Desert.

Description: The West Antarctic Ice Sheet (WAIS) Divide deep ice core WD2014 chronology, consisting of ice age, gas age, delta-age and uncertainties therein. The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ~68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP; Sigl et al., 2015, Sigl et al., 2016) have been dated using annual-layer counting based on counting of annual layers observed in the chemical, dust and electrical conductivity records. The measurements were interpreted manually and with the aid of two automated methods. We validated the chronology by comparing of the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13. We demonstrated that over the Holocene WD2014 was consistently accurate to better than 0.5% of the age. The chronology for the deep part of the core (below 2850m; 67.8-31.2 ka BP; Buizert et al., 2015) is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age-ice age difference (Delta age) using a combination of firn densification modeling, ice-flow modeling, and a data set of d15N-N2, a proxy for past firn column thickness. The largest Delta age at WD occurs during the Last Glacial Maximum, and is 525 +/- 120 years. We synchronized the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard-Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record.

Description: This data set includes noble gas measurements and modeled recharge temperatures from 32 separate groundwater studies, each analyzed using the same consistent framework and set of noble gas temperature models (CE, PR, and OD models). Along with noble gas data and modeled temperatures are site information (coordinates, recharge elevation), groundwater age data, modern recharge temperatures, other model outputs (excess air, fractionation), and uncertainties for all variables of interest. These data were used to estimate LGM-Late Holocene temperature differences from each site and, together, for the large-scale low-latitude, low-elevation land surface.