Evaluating the Drivers of Quaternary Dust Fluxes to the Western North Pacific: East Asian Dustiness and Northern Hemisphere Gustiness

Abstract

Quantifying variability in, and identifying the mechanisms behind, East Asian dust production and transport across the last several million years is essential for constraining future dust emissions and deposition. Our current understanding of East Asian dust dynamics through the Quaternary is primarily limited to low‐resolution records from the North Pacific Ocean, those from the Chinese Loess Plateau, and paleoenvironmental reconstructions from arid basins. All are susceptible to sediment winnowing and focusing as well as input of poorly constrained or unidentified non‐dust detrital material. To avoid these limitations, we examine high‐resolution, constant flux proxy‐derived dust fluxes from the North Pacific and find evidence for higher glacial dust fluxes in the early Pleistocene compared to the late Pleistocene. Our results suggest decreasing dust transported to the mid‐latitude North Pacific Ocean from eastern Asia across the Pleistocene. This observation is ostensibly at odds with previous dust records from marine sediments and the Chinese Loess Plateau, and with the perception of higher East Asian dust production and transport during the late Pleistocene associated with the amplification of glaciations. We provide three possible scenarios to describe the ∼2700‐ky evolution of eastern Asia glacial dust dynamics, and discuss them in the context of sediment production, availability, and atmospheric circulation. Our data and proposed driving mechanisms not only raise questions about the framework typically used to interpret dust archives from East Asia and the North Pacific Ocean, but also provide a roadmap for hypothesis testing and future work necessary to produce better‐constrained records of paleo‐dust fluxes.This article is protected by copyright. All rights reserved.

Constraining Plio‐Pleistocene Shifts in Northwest African Hydroclimate, Ecosystem Distributions, and Marine Productivity: New Paleo‐Records Across the Mid‐Pleistocene Transition

“…Over time, the loss of these fine-grained sediments from deflation outpaced new fine-grained sediment production leading to progressive declines in dust flux. Similar declines in dust flux to the North Pacific Ocean over the Plio-Pleistocene have been attributed to the same mechanism, suggesting that the observed dust flux decline from the Sahara may in fact be part of a larger global pattern (Abell et al, 2023). However, not all marine Plio-Pleistocene dust records agree.…”

“…Stepwise increases of dust fluxes at ∼2.8, ∼1.7, and ∼1.0 Ma were interpreted as declines in monsoon strength caused by expansions of Northern Hemisphere ice volume (de Menocal, 1995(de Menocal, , 2004Tiedemann et al, 1994). Similar increases in dust fluxes to North Pacific (Abell et al, 2021(Abell et al, , 2023Bridges et al, 2023;Rea et al, 1998), South Atlantic (Martínez-Garcia et al, 2011, North Atlantic (Crocker et al, 2022;Naafs et al, 2012) marine sediments broadly coeval with the timing inception of Northern Hemisphere glaciation (iNHG) reveal this increase in dustiness may have been a global phenomenon. However, the degree to which secular shifts in dust fluxes as well as their temporal trends are controlled by changes in hydroclimate, wind strength/positioning, and dust source region characteristics remains unclear.…”

“…Recent work, using constant flux proxy techniques (CFPs) such as 230 Th XS ‐normalization in Northwest African margin sediments showed that enhanced calcium carbonate dissolution during glacial periods causes spuriously high dust fluxes (Skonieczny et al., 2019). Moreover, in the North Pacific, long‐term trends in dust flux across the Pleistocene calculated using traditional dust flux records versus CFP methods ( 3 He ET ‐normalization) are at odds (Abell et al., 2023). Thus, in the North African context, previously reported increased dust fluxes in Northwest African margin sediments during times of expanding ice sheets may have resulted from methodological artifacts rather than increased continental aridity.…”

Modern‐Type Eolian Regime and Global Cooling‐Modulated Dust Provenance in the Late Paleogene of Central‐East Asia

“…On longer time scales, the Neogene Red Clay and the Quaternary loess deposits across the CLP are believed to have dominantly formed from northwesterly wind‐transported dust as a response to global cooling and the expansion of the Northern Hemisphere (NH) ice sheets, especially at the onset of the Quaternary (e.g., Bohm et al., 2023a; Wen et al., 2005; H. Zhang et al., 2022). Westerly winds (upper or lower level), however, seem to have dominated the dust transport to the western parts of the CLP (Shang et al., 2016) and the North Pacific Ocean (Nie et al., 2018; Rea et al., 1998), the latter exhibiting Quaternary dust fluxes that are highest during glacial periods (Abell et al., 2023). It is not uncommon in the literature (e.g., Bohm et al., 2023a) to allocate this Neogene‐Quaternary northwesterly dust transport to the EAWM, even though the major dust events occur in the spring (Roe, 2009) and as stated above, the reality of northwesterly wind dust transport is likely more complicated.…”

Orbital Controls on North Pacific Dust Flux During the Late Quaternary

“…Regional map showing annual mean precipitation (color shading; see scale bar) and 850 hPa winds (arrows), based on the NCEP-DOE reanalysis (1979-2020)(Kanamitsu et al, 2002). Marine records include core LV63-4-2 (this study), core LV76-18(Cheng et al, 2022), ODP Site 882(Serno et al, 2017), ODP Site 1208(Abell et al, 2023), ODP Site 885(Zhang, Liu, et al, 2020), core V21-146(Hovan et al, 1989), and core H3571(Kawahata et al, 2000) in the North Pacific, core MD06-3047 in the western Philippine Basin(Xu et al, 2015), core MD03-2705 in the east Atlantic(Skonieczny et al, 2019), and core RC09-166 in the Gulf of Aden(Tierney et al, 2017). Terrestrial records include the loess sequences from Jingyuan(Sun et al, 2019), Xijin(Guo et al, 2022), Xifeng(Guo et al, 2009), Luochuan(Han et al, 2020), Tacheng, and Yumin(Li et al, 2019b), and speleothem records from Sanbao(Cheng et al, 2016).…”