Open AccessReconstruction of the undiffused seasonal oxygen isotope signal in central Greenland ice cores
Author(s) -
Bolzan John F.,
Pohjola Veijo Allan
Publication year - 2000
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jc000258
Subject(s) - ice core , groenlandia , isotopes of oxygen , geology , stable isotope ratio , diffusion , δ18o , isotope , oceanography , climatology , ice sheet , physics , geochemistry , quantum mechanics , thermodynamics
The climatologically important seasonal signal in ice core oxygen isotope records is altered by diffusion with time. Here we use the diffusion model of Whillans and Grootes [1985] to calculate the effects of isotopic diffusion in nine shallow ice cores recovered over a 150 × 150 km grid centered on Summit, Greenland. Two different computational methods give similar results for the back‐diffused δ 18 O seasonal extrema. Although back diffusing the ice core δ 18 O records improves the correlations between the individual ice core oxygen isotope and Greenland coastal temperature records; the correlations remain poor, particularly for the low‐accumulation sites. Stacking the back‐diffused isotopic records from several cores results in much higher correlations, with a strong winter linkage between west coast stations and central Greenland. These correlations are also significantly greater than the correlations between the stacked measured (diffused) isotopic profiles and coastal temperatures. Our results indicate that the use of ice core isotopic records to identify anomalous seasons requires that diffusion effects be accounted for.