Numerical simulations of dust fluxes to the eastern Qinghai-Tibetan Plateau: Comparison of model results with a Holocene peat record of dust deposition

Numerical model simulations provide a useful platform for investigating the interactions between the atmospheric dust cycle and environmental change in Asia. However, model validation is still limited by the scarcity of ground observations of past terrestrial dust deposition fluxes. Here we apply a regional atmosphere-chemistry/aerosol climate model to simulate Asian dust emissions, transport, and deposition over East Asia during the years 1996-1998 and compare the present-day deposition fluxes and dominant dust sources obtained from the numerical simulations to those measured in a high-resolution Holocene palaeodust peat record on the eastern Qinghai-Tibetan Plateau. The model was found to produce reasonable dust emission fluxes from the Chinese dust sources, with average annual emissions of 179 Mt y(-1), and successfully reproduced both the dominant dust sources and average deposition fluxes to the peat core, with modeled and observed fluxes of 6.1gm(-2) y(-1). Sensitivity tests show that modeled dust fluxes are sensitive to the parameterization of erodible surfaces, and future development of the regional model to simulate dust emissions in Asia should include an improved scheme for the soil surface properties. The results presented here suggest that the regional model holds the potential to study past and present dust cycles in Asia but evidence the need for both further refinement of the model's dust parameterizations in this region and more high-resolution terrestrial validation data sets such as peat archives. This study demonstrates how present-day simulations, for which reanalysis data is available as boundary conditions, are useful tools to explore the relationship between the dust cycle and environmental change during the Holocene.