Proxy dependence of the temporal pattern of deglacial warming in the tropical South China Sea: toward resolving seasonality
Journal
Quaternary Science Reviews
Journal Volume
27
Journal Issue
44750
Pages
688-700
Date Issued
2008
Author(s)
Abstract
Sea surface temperatures (SSTs), reconstructed from two Globigerinoides ruber (white) morphotypes (G. ruber sensu stricto, (s.s.); G. ruber sensu lato, ( s.l.)) Mg/Ca and alkenones (UK′37) from core MD01-2390 from the tropical South China Sea (SCS) during the last deglaciation reveal a proxy-dependent discrepancy in the temporal pattern of the deglacial warming. Alkenone data suggest that the deglacial warming is punctuated by a decrease in temperature between ∼17 and 15 ka BP, corroborating previously published alkenone UK′37 SST records from the southern SCS. Within dating uncertainties, this cooling is coeval with the Heinrich Event 1 (H1) time interval in the North Atlantic region, underscoring the imprints of northern hemisphere forcing on tropical SCS ocean temperatures. The deglacial UK′37 SST minimum is also paralleled by a maximum in G. ruber morphotype-specific δ18O. G. ruber Mg/Ca SST estimates suggest a morphotype-specific record of SSTs during the time interval of H1. Whereas G. ruber s.s. imply a continuous warming starting around 18 ka BP without any marked response to H1, G. ruber s.l.-based Mg/Ca SST estimates reveal a cooling around ∼17-15 ka BP similar to the H1 interval cooling seen in the alkenone SST record. Similar proxy-dependent differences in deglacial surface water warming have been recorded in the eastern equatorial Pacific, implying a common pattern on both sides of the tropical Pacific Ocean. We submit that this discrepancy could be due to differences in seasonality of planktonic foraminifera G. ruber morphotypes and alkenone-producing algae. © 2007 Elsevier Ltd. All rights reserved.
SDGs
Other Subjects
Cooling; Global warming; Oceanography; Surface waters; Temperature distribution; Deglaciation; Proxy dependence; Temporal patterns; Glaciers; alga; alkenone; deglaciation; Heinrich event; morphotype; planktonic foraminifera; reconstruction; sea surface temperature; seasonality; Atlantic Ocean; Atlantic Ocean (North); Pacific Ocean; South China Sea; algae; Foraminifera; Globigerinoides ruber
Type
journal article