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Sea surfaces temperatures (SSTs) are documented in a 230-year-long sediment record from the eastern flank of Reykjanes Ridge (57°27.09'N, 27°54.53'W) in the subpolar North Atlantic with a two years average resolution.
54.3 cm long sediment box-core Rapid 21-12B was recovered from deep-sea sediments (2630 m water depth) during the RRS Charles Darwin cruise 159 in 2004. The core was dated using the 210Pb method and it was sampled continuously at 0.5 cm intervals. August SSTs are reconstructed using marine diatom species with transfer function method Weighted Averages - Partial Least Squares (WA-PLS).
Results indicate SST warming of c. 1 ∼C from 1773 AD to the present. The interval 1773-1830 represent the cold period at the investigated site, with the clearly coldest phase 1795-1825. It is followed by warm period 1830-1880. After this the temperature frequency is more stabile with short cool events around 1890 and 1930. Generally, the interval between 1940 and 2004 represents the warmest period at this site with a slow warming trend. However, the results suggest the short warmest period 1865-1875. It is noteworthy, that the high-frequency SST variability with amplitude of 1 °C appears after 1990 AD. This could suggest the instability of the North Atlantic currents due to the climate warming.
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