50 year means of oxygen isotope data from ice core NGRIP, supplement to: North Greenland Ice Core Project Members (2004): High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature, 431, 147-151
Two deep ice cores from central Greenland, drilled in the 1990s, have played a key role in climate reconstructions of the Northern Hemisphere, but the oldest sections of the cores were disturbed in chronology owing to ice folding near the bedrock. Here we present an undisturbed climate record from a...
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| Format: | Dataset |
| Language: | English |
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PANGAEA - Data Publisher for Earth & Environmental Science
2007
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| Online Access: | https://dx.doi.org/10.1594/pangaea.586886 https://doi.pangaea.de/10.1594/PANGAEA.586886 |
| Summary: | Two deep ice cores from central Greenland, drilled in the 1990s, have played a key role in climate reconstructions of the Northern Hemisphere, but the oldest sections of the cores were disturbed in chronology owing to ice folding near the bedrock. Here we present an undisturbed climate record from a North Greenland ice core, which extends back to 123,000 years before the present, within the last interglacial period. The oxygen isotopes in the ice imply that climate was stable during the last interglacial period, with temperatures 5 °C warmer than today. We find unexpectedly large temperature differences between our new record from northern Greenland and the undisturbed sections of the cores from central Greenland, suggesting that the extent of ice in the Northern Hemisphere modulated the latitudinal temperature gradients in Greenland. This record shows a slow decline in temperatures that marked the initiation of the last glacial period. Our record reveals a hitherto unrecognized warm period initiated by an abrupt climate warming about 115,000 years ago, before glacial conditions were fully developed. This event does not appear to have an immediate Antarctic counterpart, suggesting that the climate see-saw between the hemispheres (which dominated the last glacial period) was not operating at this time. : The initial isotope data series is based on 5 cm continuous sampling from surface to bottom of the core, or 61100 individual measurements. The age model follows the GRIP2001/ss09sea timescale (Johnsen et al., 2001) |
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