Thursday, December 5, 2013

New paper finds another non-hockey-stick in Turkey

A new paper published in Climate Dynamics finds another non-hockey-stick in Turkey, with temperatures at the end of the record in 2000 lower than at the beginning of the 19th and 20th centuries and during parts of the Little Ice Age. 

The reconstructed Turkish temperature data shows nothing unprecedented, unusual, or unnatural during the 20th century in comparison to the past 875 years and adds to over 1,100 non-hockey-sticks published in the peer-reviewed literature.

Volume 41Issue 7-8pp 1685-1701

Winter-to-spring temperature dynamics in Turkey derived from tree rings since AD 1125

In the eastern Mediterranean in general and in Turkey in particular, temperature reconstructions based on tree rings have not been achieved so far. Furthermore, centennial-long chronologies of stable isotopes are generally also missing. Recent studies have identified the tree species Juniperus excelsa as one of the most promising tree species in Turkey for developing long climate sensitive stable carbon isotope chronologies because this species is long-living and thus has the ability to capture low-frequency climate signals. We were able to develop a statistically robust, precisely dated and annually resolved chronology back to AD 1125. We proved that variability of δ13C in tree rings of J. excelsa is mainly dependent on winter-to-spring temperatures (January–May). Low-frequency trends, which were associated with the medieval warm period and the little ice age, were identified in the winter-to-spring temperature reconstruction, however, the twentieth century warming trend found elsewhere could not be identified in our proxy record, nor was it found in the corresponding meteorological data used for our study. Comparisons with other northern-hemispherical proxy data showed that similar low-frequency signals are present until the beginning of the twentieth century when the other proxies derived from further north indicate a significant warming while the winter-to-spring temperature proxy from SW-Turkey does not. Correlation analyses including our temperature reconstruction and seven well-known climate indices suggest that various atmospheric oscillation patterns are capable of influencing the temperature variations in SW-Turkey.

Related: First Long Temperature Reconstruction for the Eastern Mediterranean Based On Tree Rings

No comments:

Post a Comment