Spatial gradients of temperature, accumulation and δ18O-ice in Greenland over a series of Dansgaard–Oeschger events
| Autor: | Guillevic, M., Bazin, L., Landais, A., Kindler, Philippe, Orsi, A., Masson-Delmotte, V., Blunier, T., Buchardt, S. L., Capron, E., Leuenberger, Markus, Martinerie, P., Prié, F., Vinther, B. M. |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Climate of the Past, Vol 9, Iss 3, Pp 1029-1051 (2013) Guillevic, M.; Bazin, L.; Landais, A.; Kindler, Philippe; Orsi, A.; Masson-Delmotte, V.; Blunier, T.; Buchardt, S. L.; Capron, E.; Leuenberger, Markus; Martinerie, P.; Prié, F.; Vinther, B. M. (2013). Spatial gradients of temperature, accumulation and delta18O-ice in Greenland over a series of Dansgaard-Oeschger events. Climate of the past, 9(3), pp. 1029-1051. Copernicus Publications 10.5194/cp-9-1029-2013 |
| ISSN: | 1814-9332 1814-9324 |
| Popis: | Air and water stable isotope measurements from four Greenland deep ice cores (GRIP, GISP2, NGRIP and NEEM) are investigated over a series of Dansgaard–Oeschger events (DO 8, 9 and 10), which are representative of glacial millennial scale variability. Combined with firn modeling, air isotope data allow us to quantify abrupt temperature increases for each drill site (1σ = 0.6 °C for NEEM, GRIP and GISP2, 1.5 °C for NGRIP). Our data show that the magnitude of stadial–interstadial temperature increase is up to 2 °C larger in central and North Greenland than in northwest Greenland: i.e., for DO 8, a magnitude of +8.8 °C is inferred, which is significantly smaller than the +11.1 °C inferred at GISP2. The same spatial pattern is seen for accumulation increases. This pattern is coherent with climate simulations in response to reduced sea-ice extent in the Nordic seas. The temporal water isotope (δ18O)–temperature relationship varies between 0.3 and 0.6 (±0.08) ‰ °C−1 and is systematically larger at NEEM, possibly due to limited changes in precipitation seasonality compared to GISP2, GRIP or NGRIP. The gas age−ice age difference of warming events represented in water and air isotopes can only be modeled when assuming a 26% (NGRIP) to 40% (GRIP) lower accumulation than that derived from a Dansgaard–Johnsen ice flow model. |
| Databáze: | OpenAIRE |
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