Investigating the Nature of Climate Shifts during the Late Glacial and Early Holocene in the Near East, using a New Sub-Centennial Resolution Lake Isotope Record from Nar Gölü, Central Turkey

The nature of the late glacial to Holocene transition in the Near East, in terms of magnitude and rate, and the existence or not of early Holocene centennial scale climate shifts found in other regions such as the 8.2ka event, remain unresolved. High resolution records are needed to yield a better understanding of the nature of climate change over this key period and the degree to which it might be synchronous with changes in the North Atlantic or elsewhere. This will improve our understanding of the controls on Near East climate and bridge a gap in our understanding of mid latitude change at this time. A 21.5 m sediment sequence, spanning the late glacial and Holocene, has been retrieved from Nar Gölü, a maar lake in central Turkey. So far, one U-Th date provides a chronological tie-point for a varved sequence that extends for approximately 3,700 years through the early Holocene. Oxygen isotope data from carbonates (in this record a proxy for water balance) are presented at an average resolution of 25 years, the highest resolution of any record thus far produced for the Near East in this period. These high resolution oxygen isotope data allow us to demonstrate that what is believed to be the Younger Dryas-Holocene transition in the Nar Gölü record occurred in less than a century, a pattern more similar to that seen in the North Atlantic than in records of the Asian monsoon from further east. Additionally, there are three arid periods that occur at approximately the same time in the Nar Gölü record as the Pre-Boreal Oscillation, 9.3ka and 8.2ka cooling ';events' in NGRIP (Rasmussen et al., 2006, JGR). The dry Younger Dryas, and the centennial scale returns to aridity at these three occasions in the early Holocene, suggest that the Near East is drier when the North Atlantic is cooler. The rapidity of the Younger Dryas-Holocene transition indicates a strong link between North Atlantic circulation and Near East hydroclimate, probably via Mediterranean storm track frequency and winter rains. However, the longer duration of early Holocene aridity events at Nar Gölü, as seen in other records from outside of the North Atlantic region such as Qunf in Oman (Fleitmann et al., 2003, Science) and Dongge in China (Dykoski et al., 2005, EPSL), compared to shorter and more discrete ';events' seen in e.g. NGRIP and Ammersee (von Grafenstein et al., 1999, Science), suggests there are additional controls on Near East hydroclimate such as changes driven by the Indian monsoon system.