skeleton of 122 kyr-old coral
Increased seasonality in Middle East temperatures during the last interglacial period
Nature, Vol. 429, 13 MAY 2004
Thomas Felis1,2, Gerrit Lohmann1,2, Henning Kuhnert2, Stephan J. Lorenz3, Denis Scholz4, Jürgen Pätzold1,2, Saber A. Al-Rousan5 & Salim M. Al-Moghrabi5*
1 DFG Forschungszentrum Ozeanränder,
2 Fachbereich Geowissenschaften, Universität Bremen, 28359 Bremen, Germany
3 Max-Planck-Institut für Meteorologie, Modelle & Daten, 20146 Hamburg, Germany
4 Heidelberger Akademie der Wissenschaften, 69120 Heidelberg, Germany
5 Marine Science Station, University of Jordan & Yarmouk University, 77110 Aqaba, Jordan
*Present address: Aqaba Special Economic Zone Authority, 77110 Aqaba, Jordan
fossil last interglacial coral (Aqaba)
fossil last interglacial coral (Aqaba)
modern coral, Gulf of Aqaba
modern reef (Aqaba, Jordan)
Abstract
The last interglacial period (about 125,000 years ago) is thought to have been at least as warm as the present climate. Owing to changes in the Earth's orbit around the Sun, it is thought that insolation in the Northern Hemisphere varied more strongly than today on seasonal timescales, which would have led to corresponding changes in the seasonal temperature cycle. Here we present seasonally resolved proxy records using corals from the northernmost Red Sea, which record climate during the last interglacial period, the late Holocene epoch and the present. We find an increased seasonality in the temperature recorded in the last interglacial coral. Today, climate in the northern Red Sea is sensitive to the North Atlantic Oscillation, a climate oscillation that strongly influences winter temperatures and precipitation in the North Atlantic region. From our coral records and simulations with a coupled atmosphere-ocean circulation model, we conclude that a tendency towards the high-index state of the North Atlantic Oscillation during the last interglacial period, which is consistent with European proxy records, contributed to the larger amplitude of the seasonal cycle in the Middle East.
Nature, Vol. 429, 13 MAY 2004, 164-168 pdf (980 KB), html-text
Supplement pdf (1,3 MB), html-text
- press release DEKLIM, doc (32 KB)
- press release RCOM, pdf (104 KB)
- Weser Kurier vom 15. Mai jpg (160 KB)
- FAZ vom 19. Mai jpg (68 KB)
- press release Max-Planck-Institute
- press release Springer
- NAO
- Bremen und Bremerhaven: City of Science
- NOAA Paleoclimatology Program - WDC page
Information about the acceleration technique for Milankovitch type forcing in a coupled atmosphere-ocean circulation model: method and application for the Holocene by Lorenz and Lohmann
More AO/NAO and Holocene related papers:
- Rimbu, N., Lohmann, G., Felis, T., and Pätzold, J., 2001: Arctic Oscillation signature in a Red Sea coral. Geophysical Research Letters, 28 (15), 2959-2962.
- Lohmann, G., 2002: Meteorologische Interpretation geologischer Daten - neue Wege in der Paläoklimaforschung. Promet 28 (3/4), 147-152. ps (752 KB)
- Rimbu, N., Lohmann, G., Kim, J.-H., Arz, H. W., and Schneider, R., 2003: Arctic/North Atlantic Oscillation signature in Holocene sea surface temperature trends as obtained from alkenone data. Geophysical Research Letters Vol. 30, No. 6, 1280, doi:10.1029/2002GL016570. pdf (608)
- Lohmann, G., Lorenz, S., and M. Prange, 2004: Northern high-latitude climate changes during the Holocene as simulated by circulation models. AGU Monographs, Bjerknes book about the Nordic Seas, (in press) RCOM 0140.
Abstract: A global coupled atmosphere-ocean circulation model is driven by astronomical forcing in order to simulate the Holocene climate. In the Nordic Seas region, we find a long-term climate sea surface temperature decrease associated with changes in seasonal sunlight distribution. In the North Atlantic realm, a continuous cooling in the northeastern Atlantic was accompanied by a persistent warming in the Labrador Sea from the middle to the late Holocene. This temperature pattern during the Holocene can be attributed to a continuous weakening of the Icelandic Low and altered winds in the Nordic Seas. Part of the shift in the Northern Hemisphere atmospheric circulation is characterized by a tendency towards a negative phase of the Arctic Oscillation/North Atlantic Oscillation pattern. In contrast to the middle to late Holocene, where the insolation provides a crucial forcing for northern high latitudes, the strongest forcing for the Nordic Seas region in the early Holocene was probably caused by melting ice masses and a shallower Bering Strait. The effects of freshwater discharge and Bering Strait inflow are studied in a regional model of the Arctic and North Atlantic Ocean. It is suggested that a gradual increase in the influx of Pacific water through Bering Strait during the early Holocene slowly affected the polar climate by melting ice and causing circulation changes in the Nordic Seas. - Rimbu, N., Lohmann, G., Lorenz, S.J., Kim, J.-H., and Schneider, R., 2004: Holocene climate variability as derived from alkenone sea surface temperature reconstructions and coupled ocean-atmosphere model experiments. Climate Dyn. (in press). pdf (828 KB)
- Lorenz, S., and Lohmann, G., 2004: Acceleration technique for Milankovitch type forcing in a coupled atmosphere-ocean circulation model: method and application for the Holocene. Climate Dyn. (accepted for publication).Abstract
Link to Deklim (German Climate Research Programme)
Contact:
Thomas Felis
DFG Research Center Ocean Margins
University of Bremen
Klagenfurter Str.
28359 Bremen
Germany
e-mail: tfelis@allgeo.uni-bremen.de
phone: +49-421-218-7769
fax: +49-421-218-3116
http://www.rcom-bremen.de/English/Dr._Thomas_Felis.html
Gerrit Lohmann
Bremen University,
Department of Geoscience
P.O. Box 330 440
28334 Bremen
Germany
e-mail: gerrit.lohmann@dkrz.de
phone: (+49) (0)421 218 2835
fax: (+49) (0)421 218 7040
http://www.palmod.uni-bremen.de/~gerrit
