Impacts of the East Asian Monsoon on springtime dust concentrations over China

TitleImpacts of the East Asian Monsoon on springtime dust concentrations over China
Publication TypeJournal Article
Year of Publication2016
AuthorsLou S.J, Russell LM, Yang Y., Xu L, Lamjiri M.A, DeFlorio M.J, Miller AJ, Ghan SJ, Liu Y., Singh B.
JournalJournal of Geophysical Research-Atmospheres
Volume121
Pagination8137-8152
Date Published2016/07
Type of ArticleArticle
ISBN Number2169-897X
Accession NumberWOS:000380730500038
Keywordsaerosol; atmospheric; circulation; dust; earth system model; layer ozone concentrations; long-range transport; mineral dust; monsoon; north pacific; optical-properties; simulated climatology; size-distribution; trans-pacific transport
Abstract

We use 150year preindustrial simulations of the Community Earth System Model to quantify the impacts of the East Asian Monsoon strength on interannual variations of springtime dust concentrations over China. The simulated interannual variations in March-April-May (MAM) dust column concentrations range between 20-40% and 10-60% over eastern and western China, respectively. The dust concentrations over eastern China correlate negatively with the East Asian Monsoon (EAM) index, which represents the strength of monsoon, with a regionally averaged correlation coefficient of -0.64. Relative to the strongest EAM years, MAM dust concentrations in the weakest EAM years are higher over China, with regional relative differences of 55.6%, 29.6%, and 13.9% in the run with emissions calculated interactively and of 33.8%, 10.3%, and 8.2% over eastern, central, and western China, respectively, in the run with prescribed emissions. Both interactive run and prescribed emission run show the similar pattern of climate change between the weakest and strongest EAM years. Strong anomalous northwesterly and westerly winds over the Gobi and Taklamakan deserts during the weakest EAM years result in larger transport fluxes, and thereby increase the dust concentrations over China. These differences in dust concentrations between the weakest and strongest EAM years (weakest-strongest) lead to the change in the net radiative forcing by up to -8 and -3Wm(-2) at the surface, compared to -2.4 and +1.2Wm(-2) at the top of the atmosphere over eastern and western China, respectively.

DOI10.1002/2016jd024758
Student Publication: 
No