Persistent millennial-scale link between Greenland climate and northern Pacific Oxygen Minimum Zone under interglacial conditions

Abstract

Abstract. The intensity and/or extent of the northeastern Pacific Oxygen Minimum Zone (OMZ) varied in-phase with the Northern Hemisphere high latitude climate on millennial timescales during the last glacial period, indicating the occurrence of atmospheric and oceanic connections under glacial conditions. While millennial variability was reported for both the Greenland and the northern Atlantic Ocean during the last interglacial period, the climatic connections with the northeastern Pacific OMZ has not yet been observed under warm interglacial conditions. Here we present a new geochemical dataset, spanning the past 120 ka, for major components (terrigenous fraction, marine organic matter, biogenic opal, and carbonates) generated by X-ray fluorescence scanning alongside with biological productivity and redox sensitive trace element content (Mo, Ni, Cd) of sediment core MD02-2508 at 23 • N, retrieved from the northern limit of the modern OMZ. Based on elemental ratios Si / Ti (proxy for opal), Cd / Al and Ni / Al, we suggest that biological productivity was high during the last interglacial (MIS5). Highly resolved opal reconstruction presents millennial variability corresponding to all the Dansgaard-Oeschger interstadial events over the last interglacial, while the Mo / Al ratio indicates reduced oxygenation during these events. Extremely high opal content during warm interstadials suggests high diatom productivity. Despite the different climatic and oceanic background between glacial and interglacial periods, rapid variability in the northeastern Pacific OMZ seems to be tightly related to Northern Hemisphere high latitude climate via atmospheric and possibly oceanic processes.

Scenarios of Deoxygenation of the Eastern Tropical North Pacific During the Past Millennium as a Window Into the Future of Oxygen Minimum Zones

“…High-amplitude variability (such as the one described in our results) is superimposed over the long-term millennial-multimillenial O 2 trends (Nameroff et al, 2004;Cartapanis et al, 2014;Chang et al, 2014;Moffitt et al, 2015;Praetorius et al, 2015;Tetard et al, 2017). In contrast, the long-term tendencies (e.g., transition from the Last Glacial Maximum toward the Holocene) are driven by global changes in temperature and circulation that control intermediate and deep-water oxygenation (Ganeshram and Pedersen, 1998;Hendy and Pedersen, 2006;Cartapanis et al, 2014;Praetorius et al, 2015;Lu et al, 2016;Choumiline et al, 2017;Breitburg et al, 2018;Levin, 2018). In other words, short-term decreases in anoxia during warm times in response to the weakening of the Walker Circulation and increase abundance of ENSO years can counteract long-term warming of the upper ocean, which causes stratification and reduced ventilation and O 2 concentration on the global scale ocean.…”

“…A clear distinction should be made between the dominant mechanisms that control oxygenation in the ETNP over decadalcentennial timescales (Deutsch et al, 2014;Tems et al, 2015Tems et al, , 2016 and those that govern long-term glacial-interglacial variability (Ganeshram and Pedersen, 1998;Nameroff et al, 2004;Hendy and Pedersen, 2006;Ivanochko et al, 2008;Pichevin et al, 2012Pichevin et al, , 2014Cartapanis et al, 2014;Umling and Thunell, 2017). High-amplitude variability (such as the one described in our results) is superimposed over the long-term millennial-multimillenial O 2 trends (Nameroff et al, 2004;Cartapanis et al, 2014;Chang et al, 2014;Moffitt et al, 2015;Praetorius et al, 2015;Tetard et al, 2017).…”

“…A clear distinction should be made between the dominant mechanisms that control oxygenation in the ETNP over decadalcentennial timescales (Deutsch et al, 2014;Tems et al, 2015Tems et al, , 2016 and those that govern long-term glacial-interglacial variability (Ganeshram and Pedersen, 1998;Nameroff et al, 2004;Hendy and Pedersen, 2006;Ivanochko et al, 2008;Pichevin et al, 2012Pichevin et al, , 2014Cartapanis et al, 2014;Umling and Thunell, 2017). High-amplitude variability (such as the one described in our results) is superimposed over the long-term millennial-multimillenial O 2 trends (Nameroff et al, 2004;Cartapanis et al, 2014;Chang et al, 2014;Moffitt et al, 2015;Praetorius et al, 2015;Tetard et al, 2017). In contrast, the long-term tendencies (e.g., transition from the Last Glacial Maximum toward the Holocene) are driven by global changes in temperature and circulation that control intermediate and deep-water oxygenation (Ganeshram and Pedersen, 1998;Hendy and Pedersen, 2006;Cartapanis et al, 2014;Praetorius et al, 2015;Lu et al, 2016;Choumiline et al, 2017;Breitburg et al, 2018;Levin, 2018).…”

Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

“…In Lake El'gygytgyn sediments Sr is mainly associated with the occurrence of Na-Ca-feldspars and K-feldspars from the surrounding acidic and andesitic volcanic rocks (Wennrich et al, 2013) substituting for sodium, calcium, or potassium (El Bouseily and El Sokkary, 1975;Cherniak and Watson, 1994). Due to its similar ionic radius, Rb, in contrast, preferentially replaces K (Chang et al, 2013), and thus is commonly found in K-feldspars as well as mica and clay minerals (Kylander et al, 2011;Fralick and Kronberg, 1997). Hence, Rb is typically enriched in the fine-grained sediment fraction of weathering products of silicates (Koenig et al, 2011;Dypvik and Harris, 2001).…”

“…The Rb / Sr (or Sr / Rb) ratio is commonly used as an indicator of the weathering intensity of the bedrock in different kinds of sediments records (e.g., Chang et al, 2013;Jin et al, 2001;Dasch, 1969;Heymann et al, 2013), but has also been interpreted in terms of grain-size variations of Siberian lakes Teletskoye and El'gene-Kyuele (Kalugin et al, 2007;Biskaborn et al, 2013). Previous studies of Lake El'gygytgyn sediments on interglacial/glacial timescales attributed variations in the Rb / Sr ratio mainly to an enhanced Sr depletion due to higher chemical alteration, which in turn is controlled by grain size (Minyuk et al, 2011(Minyuk et al, , 2014.…”