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| Titel |
Global climate simulations at 3000-year intervals for the last 21 000 years with the GENMOM coupled atmosphere–ocean model |
| VerfasserIn |
J. R. Alder, S. W. Hostetler |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 3 ; Nr. 11, no. 3 (2015-03-17), S.449-471 |
| Datensatznummer |
250117209
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| Publikation (Nr.) |
 copernicus.org/cp-11-449-2015.pdf |
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| Zusammenfassung |
| We apply GENMOM, a coupled atmosphere–ocean climate model, to simulate eight
equilibrium time slices at 3000-year intervals for the past 21 000 years
forced by changes in Earth–Sun geometry, atmospheric greenhouse gases
(GHGs), continental ice sheets, and sea level. Simulated global cooling during
the Last Glacial Maximum (LGM) is 3.8 °C and the rate of post-glacial
warming is in overall agreement with recently published temperature
reconstructions. The greatest rate of warming occurs between 15 and 12 ka
(2.4 °C over land, 0.7 °C over oceans, and 1.4 °C
globally) in response to changes in radiative forcing from the diminished
extent of the Northern Hemisphere (NH) ice sheets and increases in GHGs and
NH summer insolation. The modeled LGM and 6 ka temperature and precipitation
climatologies are generally consistent with proxy reconstructions, the PMIP2
and PMIP3 simulations, and other paleoclimate data–model analyses. The model
does not capture the mid-Holocene "thermal maximum" and gradual cooling to
preindustrial (PI) global temperature found in the data. Simulated monsoonal
precipitation in North Africa peaks between 12 and 9 ka at values
~ 50% greater than those of the PI, and Indian monsoonal
precipitation peaks at 12 and 9 ka at values ~ 45% greater than
the PI. GENMOM captures the reconstructed LGM extent of NH and Southern
Hemisphere (SH) sea ice. The simulated present-day Antarctica Circumpolar
Current (ACC) is ~ 48% weaker than the observed (62 versus
119 Sv). The simulated present-day Atlantic Meridional Overturning
Circulation (AMOC) of 19.3 ± 1.4 Sv on the Bermuda Rise (33° N)
is comparable with observed value of 18.7 ± 4.8 Sv. AMOC at 33° N
is reduced by ~ 15% during the LGM, and the largest post-glacial
increase (~ 11%) occurs during the 15 ka time slice. |
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