Water stable isotope record of ice cores NGRIP I and II ...

• Main Authors: Gkinis, Vasileios, Simonsen, Sebastian B, Buchardt, Susanne L, White, James W C, Vinther, Bo Møllesøe
• Format: Dataset
• Language: English
• Published: PANGAEA 2018
• Subjects: DEPTH, ice/snow; δ18O, water; Ice drill; NGRIP; Sampling/drilling ice; Greenland Ice Core Projects GRIP/GISP/NGRIP; North Greenland Ice Core Project NGRIP; GISP; Greenland; Greenland ice core; Greenland Ice core Project; GRIP; ice core; North Greenland; North Greenland Ice Core Project
• Online Access: https://dx.doi.org/10.1594/pangaea.886044; https://doi.pangaea.de/10.1594/PANGAEA.886044

A high resolution (0.05 m) water isotopic record (d18O) is available from the NorthGRIP ice core. In this study we look into the water isotope diffusion history as estimated by the spectral characteristics of the d18O time series covering the last 16,000 years. The diffusion of water vapor in the porous medium of the firn pack attenuates the initial isotopic signal, predominantly having an impact on the high frequency components of the power spectrum. Higher temperatures induce higher rates of smoothing and thus the signal can be used as a firn paleothermometer. We use a water isotope diffusion model coupled to a steady-state densification model in order to infer the temperature signal from the site, assuming the accumulation and strain rate history as estimated using the GICC05 layer counted chronology and a Dansgaard-Johnsen ice flow model. The temperature reconstruction accurately captures the timing and magnitude of the Bølling-Allerød and Younger Dryas transitions. A Holocene climatic optimum is seen ... : The overlapping NGRIP I and II core sampled with a 5 cm resolution an measured on an IRMS. Even though the depth is identical, it is not expected that the age is completely identical. ...