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

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 (CLP), 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 late Pliocene-early Pleistocene compared to the late Pleistocene-Holocene. Our results suggest decreasing dust transported to the mid-latitude North Pacific Ocean from eastern Asia across the Quaternary. This observation is ostensibly at odds with previous dust records from marine sediments and the CLP, 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 similar to 2,700-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.