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DOI	10.5194/acp-20-12955-2020
	Models transport Saharan dust too low in the atmosphere: A comparison of the MetUM and CAMS forecasts with observations
	O'Sullivan D.; Marenco F.; Ryder C.L.; Pradhan Y.; Kipling Z.; Johnson B.; Benedetti A.; Brooks M.; McGill M.; Yorks J.; Selmer P.
发表日期	2020
ISSN	16807316
起始页码	12955
结束页码	12982
卷号	20 期号:21
英文摘要	We investigate the dust forecasts from two operational global atmospheric models in comparison with in situ and remote sensing measurements obtained during the AERosol properties - Dust (AER-D) field campaign. Airborne elastic backscatter lidar measurements were performed on board the Facility for Airborne Atmospheric Measurements during August 2015 over the eastern Atlantic, and they permitted us to characterise the dust vertical distribution in detail, offering insights on transport from the Sahara. They were complemented with airborne in situ measurements of dust size distribution and optical properties, as well as datasets from the Cloud-Aerosol Transport System (CATS) spaceborne lidar and the Moderate Resolution Imaging Spectroradiometer (MODIS). We compare the airborne and spaceborne datasets to operational predictions obtained from the Met Office Unified Model (MetUM) and the Copernicus Atmosphere Monitoring Service (CAMS). The dust aerosol optical depth predictions from the models are generally in agreement with the observations but display a low bias. However, the predicted vertical distribution places the dust lower in the atmosphere than highlighted in our observations. This is particularly noticeable for the MetUM, which does not transport coarse dust high enough in the atmosphere or far enough away from the source. We also found that both model forecasts underpredict coarse-mode dust and at times overpredict fine-mode dust, but as they are fine-tuned to represent the observed optical depth, the fine mode is set to compensate for the underestimation of the coarse mode. As aerosol-cloud interactions are dependent on particle numbers rather than on the optical properties, this behaviour is likely to affect their correct representation. This leads us to propose an augmentation of the set of aerosol observations available on a global scale for constraining models, with a better focus on the vertical distribution and on the particle size distribution. Mineral dust is a major component of the climate system; therefore, it is important to work towards improving how models reproduce its properties and transport mechanisms. © Author(s) 2020.
语种	英语
scopus关键词	atmospheric chemistry; atmospheric transport; backscatter; comparative study; in situ test; remote sensing; satellite data; satellite imagery; Sahara
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/152841
作者单位	Met Office, Exeter, EX1 3PB, United Kingdom; Department of Meteorology, University of ReadingRG6 6BB, United Kingdom; European Centre for Medium-Range Weather Forecasts, Reading, RG2 9AX, United Kingdom; Nasa Goddard Space Flight Center, Greenbelt, MD 20771, United States
推荐引用方式 GB/T 7714	O'Sullivan D.,Marenco F.,Ryder C.L.,et al. Models transport Saharan dust too low in the atmosphere: A comparison of the MetUM and CAMS forecasts with observations[J],2020,20(21).
APA	O'Sullivan D..,Marenco F..,Ryder C.L..,Pradhan Y..,Kipling Z..,...&Selmer P..(2020).Models transport Saharan dust too low in the atmosphere: A comparison of the MetUM and CAMS forecasts with observations.Atmospheric Chemistry and Physics,20(21).
MLA	O'Sullivan D.,et al."Models transport Saharan dust too low in the atmosphere: A comparison of the MetUM and CAMS forecasts with observations".Atmospheric Chemistry and Physics 20.21(2020).