气候变化领域集成服务门户(CCPortal): Less atmospheric radiative heating by dust due to the synergy of coarser size and aspherical shape

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DOI	10.5194/acp-21-16869-2021
	Less atmospheric radiative heating by dust due to the synergy of coarser size and aspherical shape
	Ito A.; Adebiyi A.A.; Huang Y.; Kok J.F.
发表日期	2021
ISSN	1680-7316
起始页码	16869
结束页码	16891
卷号	21 期号:22
英文摘要	Mineral dust aerosols cool and warm the atmosphere by scattering and absorbing solar (shortwave: SW) and thermal (longwave: LW) radiation. However, significant uncertainties remain in dust radiative effects, largely due to differences in the dust size distribution and spectral optical properties simulated in Earth system models. Dust models typically underestimate the coarse dust load (more than 2.5 μm in diameter) and assume a spherical shape, which leads to an overestimate of the fine dust load (less than 2.5 μm) after the dust emissions in the models are scaled to match observed dust aerosol optical depth at 550 nm (DAOD550). Here, we improve the simulated dust properties with data sets that leverage measurements of size-resolved dust concentration, asphericity factor, and refractive index in a coupled global chemical transport model with a radiative transfer module. After the adjustment of size-resolved dust concentration and spectral optical properties, the global and annual average of DAOD550 from the simulation increases from 0.023 to 0.029 and falls within the range of a semi-observationally based estimate (0.030 ± 0.005). The reduction of fine dust load after the adjustment leads to a reduction of the SW cooling at the top of the atmosphere (TOA). To improve agreement against a semi-observationally based estimate of the radiative effect efficiency at TOA, we find that a less absorptive SW dust refractive index is required for coarser aspherical dust. Thus, only a minor difference is estimated for the net global dust radiative effect at TOA (-0.08 vs. -0.00 W m-2 on a global scale). Conversely, our sensitivity simulations reveal that the surface warming is substantially enhanced near the strong dust source regions (less cooling to -0.23 from -0.60 W m-2 on a global scale). Thus, less atmospheric radiative heating is estimated near the major source regions (less heating to 0.15 from 0.59 W m-2 on a global scale), because of enhanced LW warming at the surface by the synergy of coarser size and aspherical shape. © 2021 Akinori Ito et al.
语种	英语
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246428
作者单位	Yokohama Institute for Earth Sciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Kanagawa, 236-0001, Japan; Department of Life and Environmental Sciences, University of California Merced, Merced, CA 95343, United States; Department of Atmospheric and Oceanic Sciences, University of California Los Angeles, Los Angeles, CA 90095, United States; NASA Goddard Institute for Space Studies, New York, NY 10025, United States; Earth Institute, Columbia University, New York, NY 10025, United States
推荐引用方式 GB/T 7714	Ito A.,Adebiyi A.A.,Huang Y.,et al. Less atmospheric radiative heating by dust due to the synergy of coarser size and aspherical shape[J],2021,21(22).
APA	Ito A.,Adebiyi A.A.,Huang Y.,&Kok J.F..(2021).Less atmospheric radiative heating by dust due to the synergy of coarser size and aspherical shape.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(22).
MLA	Ito A.,et al."Less atmospheric radiative heating by dust due to the synergy of coarser size and aspherical shape".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.22(2021).