Kana Nagashima

Asian dust transport during the last century recorded in Lake Suigetsu sediments

Asian dust has a significant impact on the natural environment. Its variability on multiple timescales modulates the ocean biogeochemistry and climate. We demonstrate that temporal changes in the deposition flux of Aeolian dust recorded in sediments from Lake Suigetsu, central Japan, during the last century exhibit a continuous decreasing trend and a decadal-scale decrease in 1952–1974. The former decreasing trend can be explained by a decrease in the dust storm frequency at source regions due to the warming of Mongolia in the twentieth century, suggesting future decrease of Asian dust transport with further warming in Mongolia. Decadal-scale decrease of Aeolian dust is explained by weaker westerlies in lower latitudes in central Japan, reflecting a weaker Aleutian Low during the corresponding period. Decadal-scale westerly change probably causes north–south shifts of the dominant dust transport path, which affects subarctic northern Pacific Ocean biogeochemistry by changing the micronutrient iron supply.

Additional file 2: Table S1. of Mass accumulation rate of detrital materials in Lake Suigetsu as a potential proxy for heavy precipitation: a comparison of the observational precipitation and sedimentary record

Varve count age model and fine-tuned age model with distance from the core top of SG12LM3 core. Table S2. List of top and bottom age, varve count, and its error of each â siâ input as prior probability of Bayesian analysis. Table S3. List of age differences for SG12LM3 estimated by Bayesian analysis. (XLSX 18 kb)