Black Sea temperature response to glacial millennial‐scale climate variability

Abstract

The Eurasian inland propagation of temperature anomalies during glacial millennial‐scale climate variability is poorly understood, but this knowledge is crucial to understanding hemisphere‐wide atmospheric teleconnection patterns and climate mechanisms. Based on biomarkers and geochemical paleothermometers, a pronounced continental temperature variability between 64,000 and 20,000 years ago, coinciding with the Greenland Dansgaard‐Oeschger cycles, was determined in a well‐dated sediment record from the formerly enclosed Black Sea. Cooling during Heinrich events was not stronger than during other stadials in the Black Sea. This is corroborated by modeling results showing that regular Dansgaard‐Oeschger cycles penetrated deeper into the Eurasian continent than Heinrich events. The pattern of coastal ice‐rafted detritus suggests a strong dependence on the climate background state, with significantly milder winters during periods of reduced Eurasian ice sheets and an intensified meridional atmospheric circulation.

Shift of large-scale atmospheric systems over Europe during late MIS 3 and implications for Modern Human dispersal

“…The straight yellow line represents the timing of the Campanian Ignimbrite/Y-5 tephra deposition. Black arrows indicate a trend of general continentalization.

Figure 3Direct comparison between χ fd record from Urluia (green line) and Vlasca (blue line), χ fd from Titel loess-palaeosol sequence 37 (orange line; Middle Danube Basin) and their comparison with the mean annual lake surface temperature (LST; red line) of the Black Sea 26 over 25,000–50,000 years ago.

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Re‐analysis of late Quaternary dust mass accumulation rates in Serbia using new luminescence chronology for loess–palaeosol sequence at Surduk

“…The MIS 3 period was considered a climatically milder and more stable component of the previous interglacial (Wegwerth et al . ), but containing pronounced oscillations (Hoffecker ; Fischer et al . ).…”

Impact of Eurasian Ice Sheet and North Atlantic Climate Dynamics on Black Sea Temperature Variability During the Penultimate Glacial (MIS 6, 130–184 ka BP)

“…There is strong evidence for pronounced millennial-scale temperature variability during MIS 3, not only at the iconic sites from the North Atlantic and Greenland (e.g., Bond et al, 1993;Dansgaard et al, 1993;Martrat et al, 2007;McManus et al, 1999) but also from the Eurasian continental interior including the Black Sea, confirming a deep inland propagation of temperature anomalies through atmospheric teleconnections (e.g., Fleitmann et al, 2009;Tzedakis et al, 2004;Wegwerth et al, 2015). In contrast to stadial-interstadial temperature changes during the so-called Dansgaard-Oeschger (DO) cycles, the extra cooling during Heinrich stadials was most likely restricted to the eastern midlatitude North Atlantic (e.g., Ganopolski & Rahmstorf, 2001;Martrat et al, 2007).…”

“…To test the effect of the different boundary conditions on climate variability on the Eurasian continent during MIS 6 and MIS 3, we have reconstructed surface water temperature by means of the TEX 86 (TetraEther IndeX of lipids with 86 carbon atoms; Schouten et al, 2013) paleothermometer from a composite sediment core covering the penultimate glacial phase of the former SE Black Sea "Lake." We further included the content of coastal ice-rafted detritus (IRD C ), which has been proven a further valuabletemperature-related proxy (Nowaczyk et al, 2012;Wegwerth et al, 2014Wegwerth et al, , 2015Wegwerth et al, , 2019.…”

“…The mean standard deviation of measurements of an in-house TEX 86 standard was 0.008 (0.4°C, with the calibration of Powers et al, 2010; n = 16). The TEX 86 is expected to mirror mean near-surface annual temperatures during the glacial stages of the Black Sea (Wegwerth et al, 2014;Wegwerth et al, 2015). The Branched and Isoprenoid Tetraether (BIT) index represents the relative abundance of terrestrial tetraether lipids to crenarchaeol and was calculated according to Hopmans et al (2004).…”