Dust and temperature influences on glaciofluvial sediment deposition in southwestern Tibet during the last millennium

• We developed a 960-year record of glaciofluvial sediment deposition.
• Glaciofluvial sediment deposition is correlated with regional ice core dust.
• Dust forcing was coherent across central Himalayas over the last millennium.
• Glaciofluvial sediment deposition is also correlated with warm season temperature.
• Southwestern Tibet shows a May–September warming trend over the 20th century.

Dust over the Himalayas and southern Tibetan Plateau may influence high-elevation temperature and hydrology across Asia, but little is known about long-term dust variability and its relationship with regional climate over the last millennium. Here we have reconstructed a proxy record of past dust and temperature impacts on glacial streamflow and sediment deposition in Kiang Co, a small lake on the southwestern Tibetan Plateau. Terrigenous elemental variability in the Kiang Co sediment record, a proxy for glaciofluvial sediment deposition in the lake, covaries with the Dasuopu ice core dust record from the central Himalayas on centennial timescales. The relationship between the Kiang Co sediment record and Dasuopu indicates coherent dust forcing across the central Himalayas over much of the last millennium, and suggests that regional dustiness influences glacial streamflow and sediment transport on centennial timescales. In addition, the Kiang Co terrigenous elemental abundance record is positively correlated with May–September temperatures from the Tibetan Plateau to central India from 1870 to 2007 AD, highlighting the important influence of temperature on melting and streamflow in this region, as well as a relationship between dust and temperature on centennial timescales. These findings strengthen the likelihood of future dustiness with continued warming, along with further increases in melting and high-elevation streamflow in coming decades.