HR: 08:30h
AN: PP41C-03 INVITED     [Abstracts]
TI: Increased Seasonality in Middle East Hydrologic Balance During the mid Holocene
AU: * Felis, T
EM: tfelis@uni-bremen.de
AF: DFG-Research Center for Ocean Margins, University of Bremen, Bremen, 28359 Germany
AU: Kuhnert, H
PP41C-03 AF: DFG-Research Center for Ocean Margins, University of Bremen, Bremen, 28359 Germany
AU: Lohmann, G
PP41C-03 AF: Alfred-Wegener-Institute for Polar and Marine Research, Paleo-climate Dynamics, Bremerhaven, 27570 Germany
AU: Al-Rousan, S A
PP41C-03 AF: Marine Science Station, University of Jordan & Yarmouk University, Aqaba, 77110 Jordan
AU: Pätzold, J
PP41C-03 AF: DFG-Research Center for Ocean Margins, University of Bremen, Bremen, 28359 Germany
AB: An abrupt termination of the early Holocene humid period in the southeastern Mediterranean/Middle East around 6.2 kyr ago is indicated by marine sediment records from the northernmost Red Sea. Not much, however, is known about changes in the region's hydrologic balance on seasonal to interannual timescales during the mid to late Holocene. Hydrologic changes on these timescales should have potentially affected past civilizations in this arid region. Here we present seasonally resolved proxy records of mid- to late Holocene climate in the southeastern Mediterranean/Middle East, based on annually-banded reef corals ( Porites) from the northernmost Red Sea (northern Gulf of Aqaba, 29.5 degrees North). Oxygen isotope and Sr/Ca records generated from individual coral colonies cover time windows of decades to a century. Relative to modern and late Holocene conditions, the coral records suggest a strongly increased seasonality in the hydrologic balance for time windows around 4.6 and 4.4 kyr ago. Such an increased seasonal cycle of hydrologic balance could result from both enhanced evaporation during winter or increased precipitation during summer, although the latter is rather unlikely in this arid region. Furthermore, slightly increased temperature seasonality is indicated for most of the time windows between 5.6 and 3.6 kyr ago. Today, enhanced evaporation in the northernmost Red Sea during winter is paradoxically associated with increased winter precipitation along the southeastern margin of the Mediterranean Sea. Furthermore, the Arctic Oscillation/North Atlantic Oscillation phenomenon has a strong control on the region's winter climate on interannual and orbital timescales, with consequences for the seasonal cycles of temperature and hydrologic balance. Combining our coral records with state-of-the-art climate model simulations will help to identify the controlling mechanisms for changes in the seasonal cycle in the Middle East during the Holocene. This provides a crucial step in understanding and predicting pronounced changes in past, present and future Middle East climate.
DE: 1620 Climate dynamics (0429, 3309)
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
DE: 4916 Corals (4220)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005