A Lake at the Mt. Fuji (Lake Motosu) Recording Prolonged Negative Arctic Oscillation as Reduction of Aeolian Dust Due To Westerly Pathways During the Holocene

East Asia is a major source of dust accounting for 20% of the global dust emission. Work on reconstructing past changes in dust transport in East Asia is complicated by difficulties in distinguishing local sedimentation from aerial material and lack of suitable material for age determination. Here, we address these issues and present a new dust proxy record from Lake Motosu, located on the Pacific side of Japan. The record is anchored by a high‐quality tephra and radiocarbon chronology. Because Lake Motosu is situated in a quartz‐free basaltic volcanic province, all quartz deposited in the lake is likely to be aerially sourced, and variations in quartz content should reflect past changes in dust transport. Our new record detects a low dust deposition event from 3.0 to 2.0 ka. This event corresponds to elevated sea surface temperature in the Sea of Japan and climate conditions similar to a negative phase of the Arctic Oscillation, indicating an association with the weakened Westerlies and with less frequent dust storms in the source region. The increase in spatial resolution of past dust transport reconstructions will further improve our understanding of the mechanism related to dust emission from East Asia. One potential proxy for understanding past changes in atmospheric conditions is aeolian dust. The climate variability links between non‐contiguous geographic regions and strong constraints on geological ages are required to better contribute to the understanding of dust transport. Here, the dust deposition history of the past 8,000 years at Lake Motosu was obtained by quantitative X‐ray diffraction analysis to determine the amount of quartz in the sediments. There is no local source of quartz to Lake Motosu, so we consider that quartz is transported to the lake in the atmosphere. The amount of dust deposition to the Lake Motosu has persistently decreased between 3 and 2 thousand ago. This sustained decrease in dust deposition may be caused by conditions similar to a negative phase of the Arctic Oscillation. This interpretation is consistent with other proxy records from East Asia. Dust deposition history of the past 8 kyr at Lake Motosu was obtained by quantifying quartz amount by X‐ray diffraction analysisReduced amounts of dust accumulation are recognized between 3 and 2 ka, suggesting the Westerlies were away from Lake MotosuClimate conditions similar to a negative phase of the Arctic Oscillation may be the cause of the sustained decrease in dust deposition Dust deposition history of the past 8 kyr at Lake Motosu was obtained by quantifying quartz amount by X‐ray diffraction analysis Reduced amounts of dust accumulation are recognized between 3 and 2 ka, suggesting the Westerlies were away from Lake Motosu Climate conditions similar to a negative phase of the Arctic Oscillation may be the cause of the sustained decrease in dust deposition