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Read Full Article (file size: 430389 bytes) Cited by
GEOPHYSICAL RESEARCH LETTERS,
VOL. 33,
L18710,
doi:10.1029/2006GL026384,
2006
Indian Ocean zonal mode activity in a multicentury integration of a coupled AOGCM consistent with climate proxy data
Thomas Mölg
Tropical Glaciology Group, Department of Earth and Atmospheric Sciences, University of Innsbruck, Innsbruck, Austria
Manuel Renold
Climate and Environmental Physics, Physics Institute, University of Berne, Berne, Switzerland
Mathias Vuille
Climate System Research Center, Department of Geosciences, University of Massachusetts, Amherst, Massachusetts, USA
Nicolas J. Cullen
Tropical Glaciology Group, Department of Earth and Atmospheric Sciences, University of Innsbruck, Innsbruck, Austria
Thomas F. Stocker
Climate and Environmental Physics, Physics Institute, University of Berne, Berne, Switzerland
Georg Kaser
Tropical Glaciology Group, Department of Earth and Atmospheric Sciences, University of Innsbruck, Innsbruck, Austria
Abstract
The coupled atmosphere-ocean system over the Indian Ocean (termed Indian Ocean Zonal Mode, IOZM) and its activity over the
past 200 years is analyzed in a paleoclimate simulation from a coupled atmosphere-ocean general circulation model (AOGCM).
Validation shows that the AOGCM captures spatio-temporal patterns of sea surface temperature anomalies as well as the seasonal
phase-locking feature of the IOZM. The period 1820–1880 exhibits a high frequency of climatically significant IOZM events,
compared to a relatively low frequency in the 20th century. This shift in frequency provides a climate dynamics background
for the interpretation of proxy data from East Africa, a region subjected to anomalously strong October–December precipitation
during IOZM events. In the late 19th century, East African lakes had highstands (e.g., Lake Victoria) and its glaciers stable
extents (e.g., Kilimanjaro), consistent with a wetter climate due to the higher frequency of IOZM events.
Received 22
March
2006;
accepted 21
August
2006;
published 30
September
2006.
Index Terms: 3344 Atmospheric Processes: Paleoclimatology (0473, 4900); 3339 Atmospheric Processes: Ocean/atmosphere interactions (0312, 4504); 3305 Atmospheric Processes: Climate change and variability (1616, 1635, 3309, 4215, 4513); 3337 Atmospheric Processes: Global climate models (1626, 4928).
Read Full Article (file size: 430389 bytes) Cited by
Citation: Mölg, T., M. Renold, M. Vuille, N. J. Cullen, T. F. Stocker, and G. Kaser
(2006),
Indian Ocean zonal mode activity in a multicentury integration of a coupled AOGCM consistent with climate proxy data,
Geophys. Res. Lett.,
33,
L18710,
doi:10.1029/2006GL026384.
Copyright 2006 by the American Geophysical Union.
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