Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.5194/acp-17-297-2017 |
Particle settling and vertical mixing in the Saharan Air Layer as seen from an integrated model, lidar, and in situ perspective | |
Gasteiger, Josef1,2; Gross, Silke3; Sauer, Daniel3; Haarig, Moritz4; Ansmann, Albert4; Weinzierl, Bernadett2 | |
2017-01-05 | |
发表期刊 | ATMOSPHERIC CHEMISTRY AND PHYSICS |
ISSN | 1680-7316 |
EISSN | 1680-7324 |
出版年 | 2017 |
卷号 | 17期号:1 |
文章类型 | Article |
语种 | 英语 |
国家 | Germany; Austria |
英文摘要 | Long-range transport of aerosol in the Saharan Air Layer (SAL) across the Atlantic plays an important role for weather, climate, and ocean fertilization. However, processes occurring within the SAL and their effects on aerosol properties are still unclear. In this work we study particle settling and vertical mixing within the SAL based on measured and modeled vertical aerosol profiles in the upper 1 km of the transported SAL. We use ground-based lidar measurements and airborne particle counter measurements over the western Atlantic, collected during the SALTRACE campaign, as well as space-based CALIOP lidar measurements from Africa to the western Atlantic in the summer season. In our model we take account of the optical properties and the Stokes gravitational settling of irregularly shaped Saharan dust particles. We test two hypotheses about the occurrence of vertical mixing within the SAL over the Atlantic to explain the aerosol profiles observed by the lidars and the particle counter. Our first hypothesis (H1) assumes that no mixing occurs in the SAL leading to a settling-induced separation of particle sizes. The second hypothesis (H2) assumes that vertical mixing occurs in the SAL allowing large super-micron dust particles to stay airborne longer than without mixing. The uncertainties of the particle linear depolarization ratio (delta(l)) profiles measured by the ground-based lidars are comparable to the modeled differences between H1 and H2 and do not allow us to conclude which hypothesis fits better. The SALTRACE in situ data on size-resolved particle number concentrations show a presence of large particles near the SAL top that is inconsistent with H1. The analysis of the CALIOP measurements also reveals that the average delta(l) profile over the western Atlantic is inconsistent with H1. Furthermore, it was found that the average delta(l) profile in the upper 1 km of the SAL does not change along its transport path over the Atlantic. These findings give evidence that vertical mixing within the SAL is a common phenomenon with significant consequences for the evolution of the size distribution of super-micron dust particles during transport over the Atlantic. Further research is needed to precisely characterize the processes that are relevant for this phenomenon. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000392404400003 |
WOS关键词 | LINEAR DEPOLARIZATION RATIO ; MINERAL DUST AEROSOL ; OPTICAL-PROPERTIES ; SIZE DISTRIBUTION ; TRANSPORT ; CLOUD ; SHAPE ; AIRBORNE ; SAMUM-1 ; STATE |
WOS类目 | Environmental Sciences ; Meteorology & Atmospheric Sciences |
WOS研究方向 | Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/23870 |
专题 | 地球科学 |
作者单位 | 1.Ludwig Maximilians Univ Munchen, Meteorol Inst, Munich, Germany; 2.Univ Vienna, Fac Phys, Vienna, Austria; 3.Deutsch Zentrum Luft & Raumfahrt, Inst Phys Atmosphare, Oberpfaffenhofen, Germany; 4.Leibniz Inst Tropospher Res, Leipzig, Germany |
推荐引用方式 GB/T 7714 | Gasteiger, Josef,Gross, Silke,Sauer, Daniel,et al. Particle settling and vertical mixing in the Saharan Air Layer as seen from an integrated model, lidar, and in situ perspective[J]. ATMOSPHERIC CHEMISTRY AND PHYSICS,2017,17(1). |
APA | Gasteiger, Josef,Gross, Silke,Sauer, Daniel,Haarig, Moritz,Ansmann, Albert,&Weinzierl, Bernadett.(2017).Particle settling and vertical mixing in the Saharan Air Layer as seen from an integrated model, lidar, and in situ perspective.ATMOSPHERIC CHEMISTRY AND PHYSICS,17(1). |
MLA | Gasteiger, Josef,et al."Particle settling and vertical mixing in the Saharan Air Layer as seen from an integrated model, lidar, and in situ perspective".ATMOSPHERIC CHEMISTRY AND PHYSICS 17.1(2017). |
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