干旱区生态环境知识资源中心(Arid): Coarse and giant particles are ubiquitous in Saharan dust export regions and are radiatively significant over the Sahara

Arid

DOI	10.5194/acp-19-15353-2019
	Coarse and giant particles are ubiquitous in Saharan dust export regions and are radiatively significant over the Sahara
	Ryder, Claire L.1; Highwood, Eleanor J.1; Walser, Adrian 2; Seibert, Petra 3; Philipp, Anne 2; Weinzierl, Bernadett 2
通讯作者	Ryder, Claire L.
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
ISSN	1680-7316
EISSN	1680-7324
出版年	2019
卷号	19 期号:24 页码:15353-15376
英文摘要	Mineral dust is an important component of the climate system, interacting with radiation, clouds, and biogeochemical systems and impacting atmospheric circulation, air quality, aviation, and solar energy generation. These impacts are sensitive to dust particle size distribution (PSD), yet models struggle or even fail to represent coarse (diameter (d) > 2.5 mu m) and giant (d > 20 mu m) dust particles and the evolution of the PSD with transport. Here we examine three state-of-the-art airborne observational datasets, all of which measured the full size range of dust (d = 0.1 to > 100 mu m) at different stages during transport with consistent instrumentation. We quantify the presence and evolution of coarse and giant particles and their contribution to optical properties using airborne observations over the Sahara (from the Fennec field campaign) and in the Saharan Air Layer (SAL) over the tropical eastern Atlantic (from the AER-D field campaign). Observations show significantly more abundant coarse and giant dust particles over the Sahara compared to the SAL: effective diameters of up to 20 mu m were observed over the Sahara compared to 4 mu m in the SAL. Excluding giant particles over the Sahara results in significant underestimation of mass concentration (40 %), as well as underestimates of both shortwave and longwave extinction (18% and 26 %, respectively, from scattering calculations), while the effects in the SAL are smaller but non-negligible. The larger impact on longwave extinction compared to shortwave implies a bias towards a radiative cooling effect in dust models, which typically exclude giant particles and underestimate coarse-mode concentrations. A compilation of the new and published effective diameters against dust age since uplift time suggests that two regimes of dust transport exist. During the initial 1.5 d, both coarse and giant particles are rapidly deposited. During the subsequent 1.5 to 10 d, PSD barely changes with transport, and the coarse mode is retained to a much greater degree than expected from estimates of gravitational sedimentation alone. The reasons for this are unclear and warrant further investigation in order to improve dust transport schemes and the associated radiative effects of coarse and giant particles in models.
类型	Article
语种	英语
国家	England ; Austria
开放获取类型	gold, Green Accepted
收录类别	SCI-E
WOS记录号	WOS:000503444400002
WOS关键词	DISPERSION MODEL FLEXPART ; CLOUD CONDENSATION NUCLEI ; LONG-RANGE TRANSPORT ; IN-SITU MEASUREMENTS ; MINERAL DUST ; OPTICAL-PROPERTIES ; DESERT DUST ; SIZE DISTRIBUTION ; ATMOSPHERIC TRANSPORT ; CHEMICAL-PROPERTIES
WOS类目	Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
EI主题词	2019-12-17
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/311817
作者单位	1.Univ Reading, Dept Meteorol, Reading RG6 6BB, Berks, England; 2.Univ Vienna, Fac Phys Aerosol Phys & Environm Phys, Vienna, Austria; 3.Univ Nat Resources & Life Sci, Inst Meteorol, Vienna, Austria
推荐引用方式 GB/T 7714	Ryder, Claire L.,Highwood, Eleanor J.,Walser, Adrian,et al. Coarse and giant particles are ubiquitous in Saharan dust export regions and are radiatively significant over the Sahara[J],2019,19(24):15353-15376.
APA	Ryder, Claire L.,Highwood, Eleanor J.,Walser, Adrian,Seibert, Petra,Philipp, Anne,&Weinzierl, Bernadett.(2019).Coarse and giant particles are ubiquitous in Saharan dust export regions and are radiatively significant over the Sahara.ATMOSPHERIC CHEMISTRY AND PHYSICS,19(24),15353-15376.
MLA	Ryder, Claire L.,et al."Coarse and giant particles are ubiquitous in Saharan dust export regions and are radiatively significant over the Sahara".ATMOSPHERIC CHEMISTRY AND PHYSICS 19.24(2019):15353-15376.