Research-Paleoclimate modeling

 

Eolian dust from the inner Asian deserts during the late Pliocene and Pleistocene periods

 
 

    Northern Tibetan Plateau uplift and global climate change are regarded as two important factors responsible for a remarkable increase in dust concentration originating from the inner Asian deserts during the Pliocene-Pleistocene period. Dust cycles during the mid-Pliocene, last glacial maximum (LGM), and present day are simulated with a global climate model, based on reconstructed dust source scenarios, to evaluate the relative contributions of the two factors to the increment of dust sedimentation fluxes. Our results are in good agreement with marine and terrestrial observations over downwind deposit regions. The increases in aerosol mass accumulation rate (MAR) can be attributed to both the regional tectonic uplift and global climate change. Comparatively, the climatic factors, including the ice sheet and sea surface temperature changes, have modulated the regional surface wind field and controlled the intensity of sedimentation flux over the Loess Plateau. The impact of the Tibetan Plateau uplift, which increased the areas of inland deserts in Asia, is more important for aerosol deposition over the North Pacific.

Shi Z.G., X.D. Liu, Z.S. An, B.Q. Yi, P. Yang, N. Mahowald, 2011: Simulated variations of eolian dust from inner Asian deserts at the mid-Pliocene, last glacial maximum, and present day: contributions from the regional tectonic uplift and global climate change, Climate DynamicsDOI: 10.1007/s00382-011-1078-1.

The simulated dust deposition fluxes (g/cm2/kyr) originating from the Asian deserts for the present-day (a), LGM (b), and mid-Pliocene (c). 

Simulated dust MARs averaged over the North Pacific (a) and Loess Plateau (b): MAR levels from the reconstructed dust source maps are marked as red triangles and blue dash lines with the corresponding value of MARs, respectively; The curves indicate the reconstructed MARs based on geological evidence (ODP 885/886, black; ZJC/LT, grey) for comparison; The period of Quaternary (~2.6Myr) is shaded in yellow.