Orbital-controlled mid-latitude North Pacific dust flux during the late Quaternary

Airborne mineral dust is sensitive to climatic changes, but its response to orbital forcing is still not fully understood. Here, we present a reconstruction of dust input to the Subarctic Pacific Ocean covering the past 190 kyr. The dust composition record is indicative of source moisture conditions, which are dominated by precessional variations. In contrast, the dust flux in marine sediments is dominated by obliquity variations, and display an out-of-phase relationship with a dust record from the mid latitude North Pacific Ocean. Climate model simulations suggest a precessional forcing likely affected the aridity and extent of the dust source regions. Meanwhile, the obliquity variations can be explained by meridional shifts in the North Pacific westerly jet, driven by changes in the meridional atmospheric temperature gradient. Our findings suggest that North Pacific dust input were primarily modulated by orbital-controlled source aridity and westerly during the late Quaternary.