Patterns of deglacial warming in the Pacific Ocean: a review with emphasis on the time interval of Heinrich event 1

Abstract

Based on a compilation of currently available records of past sea surface temperature (SST) variability, estimated from a variety of different proxies, the regional-scale deglacial SST development in the Pacific Ocean is tentatively classified into four endmember types. The subtropical and tropical Pacific is characterized by a continuous deglacial warming without marked interruption during the time interval of Heinrich event 1 (H1), whereas the subarctic North Pacific exhibits centennial-scale warm-cold oscillations during this time interval. SST records from marginal seas of the Pacific show a deglacial warming interrupted by a cooling event coeval with H1, followed by a marked Bølling SST increase. A single SST record from the southwestern subantarctic Pacific displays a continuous deglacial warming across H1 followed by an Antarctic Cold Reversal-type cooling during the Allerød. Thus, in contrast to the deglacial SST development in the Atlantic, which has been inferred to be overwhelmingly driven by the redistribution of heat through changes in the meridional overturning circulation (MOC), none of the open oceanic Pacific SST records reviewed here displays any obvious and/or dominant response to the reduction of the MOC and/or the reorganization of atmospheric circulation during H1. Within the limits of absolute chronologies, all tropical and subtropical Pacific SST records show an onset of deglacial warming at 19±1 ka, coeval with the onset of the deglacial rise in sea level.