Glacial-to-Holocene evolution of sea surface temperature and surface circulation in the subarctic northwest Pacific and the Western Bering Sea

Abstract

It has been proposed that North Pacific sea surface temperature (SST) evolution was intimately linked to North Atlantic climate oscillations during the last glacial-interglacial transition. However, during the early deglaciation and the Last Glacial Maximum, the SST development in the subarctic northwest Pacific and the Bering Sea is poorly constrained as most existing deglacial SST records are based on alkenone paleothermometry, which is limited prior to 15 ka B.P. in the subarctic North Pacific realm. By applying the TEX L 86 temperature proxy we obtain glacial-Holocene-SST records for the marginal northwest Pacific and the Western Bering Sea. Our TEX L 86 -based records and existing alkenone data suggest that during the past 15.5 ka, SSTs in the northwest Pacific and the Western Bering Sea closely followed millennial-scale climate fluctuations known from Greenland ice cores, indicating rapid atmospheric teleconnections with abrupt climate changes in the North Atlantic. Our SST reconstructions indicate that in the Western Bering Sea SSTs drop significantly during Heinrich Stadial 1 (HS1), similar to the known North Atlantic climate history. In contrast, progressively rising SST in the northwest Pacific is different to the North Atlantic climate development during HS1. Similarities between the northwest Pacific SST and climate records from the Gulf of Alaska point to a stronger influence of Alaskan Stream waters connecting the eastern and western basin of the North Pacific during this time. During the Holocene, dissimilar climate trends point to reduced influence of the Alaskan Stream in the northwest Pacific.

Summer temperature evolution on the Kamchatka Peninsula, Russian Far East, during the past 20 000 years

“…For this study we used the same samples as Meyer et al (2016). These authors sampled the core in 10 cm steps, providing an average temporal resolution of approximately 200 years.…”

“…Black pins represent the age control points from core 12KL (based on radiocarbon dating of planktonic foraminifera; Max et al, 2012). (c) BIT index values of core 12KL (Meyer et al, 2016). (d) Titanium / calcium ratios (Ti / Ca, XRF-scan core 12KL; Max et al, 2012).…”

“…The higher the BIT value, the more abundant the brGDGT relative to the crenarchaeol and the higher the terrigenous input. BIT values were adopted from Meyer et al (2016), who worked on the same samples as used in this study.…”

“…These authors sampled the core in 10 cm steps, providing an average temporal resolution of approximately 200 years. For GDGT (glycerol dialkyl glycerol tetraether) analyses, freeze-dried and homogenized sediment samples (approximately 5 g) were extracted and processed according to Meyer et al (2016).…”

“…There is consensus among sea surface temperature records from the northern Pacific (N Pacific) and its marginal seas that the deglaciation was characterized by abrupt warm-cold oscillations (e.g., Barron et al, 2003;Seki et al, 2009Seki et al, , 2014Caissie et al, 2010;Max et al, 2012;Praetorius and Mix, 2014;Praetorius et al, 2015;Meyer et al, 2016), suggesting teleconnections with the North Atlantic realm (Manabe and Stouffer, 1988;Mikolajewicz et al, 1997;Okumura et al, 2009;Chikamoto et al, 2012). However, it is not fully understood how far this North Atlantic (N Atlantic) connection extended into Beringia.…”