scholarly journals Aerosol‐cloud‐precipitation interactions during a Saharan dust event ‐ a summertime case study from the Alps

2021 ◽  
Author(s):  
Gesa K. Eirund ◽  
Saskia D. Dusseldorp ◽  
Benjamin T. Brem ◽  
Zane Dedekind ◽  
Yves Karrer ◽  
...  
Keyword(s):  
Saharan Dust ◽  
Dust Event ◽  
Aerosol Cloud ◽  
The Alps

scholarly journals WRF-CHEM SIMULATION OF A SAHARAN DUST OUTBREAK OVER THE MEDITERRANEAN REGIONS

2016 ◽  
Vol 38 ◽  
pp. 330 ◽  
Author(s):  
Umberto Rizza ◽  
Vagner Anabor ◽  
Cristina Mangia ◽  
Mario Marcello Miglietta ◽  
Gervasio Annes Degrazia ◽  
...  
Keyword(s):  
Dust Emission ◽  
Saharan Dust ◽  
Dust Event ◽  
Aerosol Model ◽  
Tuning Parameters ◽  
Mediterranean Regions ◽  
Time Average ◽  
The Mediterranean ◽  
Fully Coupled

A fully coupled meteorology-chemistry-aerosol model (WRF-Chem) is applied to simulate the Saharan dust outbreak over the Mediterranean regions. Two dust emission schemes, namely, those of Jones et al., (2010), and Shao (2001) are evaluated using the the GOCART aerosol model. To investigate the performance of each dust emission scheme, a case study was carried out for a Mediterranean dust event that took place between 21 and 23 May 2014. Considering the time average Aerosol Optical Depth, simulation results reproduced satisfactorily the outbreak and transport pattern of dust plumes. However, the estimated dust emission amounts in each scheme differ greatly due to the presence of several tuning parameters, that must be adjusted considering satellite and ground based experimental data.

scholarly journals The Potential of GRASP/GARRLiC Retrievals for Dust Aerosol Model Evaluation: Case Study during the PreTECT Campaign

2021 ◽  
Vol 13 (5) ◽  
pp. 873
Author(s):  
Dimitra Konsta ◽  
Alexandra Tsekeri ◽  
Stavros Solomos ◽  
Nikolaos Siomos ◽  
Anna Gialitaki ◽  
...  
Keyword(s):  
Model Evaluation ◽  
Dust Concentration ◽  
Saharan Dust ◽  
North Coast ◽  
Concentration Profiles ◽  
Future Studies ◽  
Aerosol Model ◽  
The North ◽  
Sun Photometer

We use the Generalized Retrieval of Aerosol Surface Properties algorithm (GRASP) to compare with dust concentration profiles derived from the NMME-DREAM model for a specific dust episode. The GRASP algorithm provides the possibility of deriving columnar and vertically-resolved aerosol properties from a combination of lidar and sun-photometer observations. Herein, we apply GRASP for analysis of a Saharan dust outburst observed during the “PREparatory: does dust TriboElectrification affect our ClimaTe” campaign (PreTECT) that took place at the North coast of Crete, at the Finokalia ACTRIS station. GRASP provides column-averaged and vertically resolved microphysical and optical properties of the particles. The retrieved dust concentration profiles are compared with modeled concentration profiles derived from the NMME-DREAM dust model. To strengthen the results, we use dust concentration profiles from the POlarization-LIdar PHOtometer Networking method (POLIPHON). A strong underestimation of the maximum dust concentration is observed from the NMME-DREAM model. The reported differences between the retrievals and the model indicate a high potential of the GRASP algorithm for future studies of dust model evaluation.

scholarly journals Radiative Effect and Mixing Processes of a Long-Lasting Dust Event over Athens, Greece, during the COVID-19 Period

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 318
Author(s):  
Panagiotis Kokkalis ◽  
Ourania Soupiona ◽  
Christina-Anna Papanikolaou ◽  
Romanos Foskinis ◽  
Maria Mylonaki ◽  
...  
Keyword(s):  
Atmospheric Pollutants ◽  
Saharan Dust ◽  
Radiative Effect ◽  
Atmospheric Conditions ◽  
Dust Event ◽  
Mixing Processes ◽  
Hysplit Model ◽  
European Continent ◽  
Dust Layer ◽  
Ground Based Lidar

We report on a long-lasting (10 days) Saharan dust event affecting large sections of South-Eastern Europe by using a synergy of lidar, satellite, in-situ observations and model simulations over Athens, Greece. The dust measurements (11–20 May 2020), performed during the confinement period due to the COVID-19 pandemic, revealed interesting features of the aerosol dust properties in the absence of important air pollution sources over the European continent. During the event, moderate aerosol optical depth (AOD) values (0.3–0.4) were observed inside the dust layer by the ground-based lidar measurements (at 532 nm). Vertical profiles of the lidar ratio and the particle linear depolarization ratio (at 355 nm) showed mean layer values of the order of 47 ± 9 sr and 28 ± 5%, respectively, revealing the coarse non-spherical mode of the probed plume. The values reported here are very close to pure dust measurements performed during dedicated campaigns in the African continent. By utilizing Libradtran simulations for two scenarios (one for typical midlatitude atmospheric conditions and one having reduced atmospheric pollutants due to COVID-19 restrictions, both affected by a free tropospheric dust layer), we revealed negligible differences in terms of radiative effect, of the order of +2.6% (SWBOA, cooling behavior) and +1.9% (LWBOA, heating behavior). Moreover, the net heating rate (HR) at the bottom of the atmosphere (BOA) was equal to +0.156 K/d and equal to +2.543 K/d within 1–6 km due to the presence of the dust layer at that height. On the contrary, the reduction in atmospheric pollutants could lead to a negative HR (−0.036 K/d) at the bottom of the atmosphere (BOA) if dust aerosols were absent, while typical atmospheric conditions are estimated to have an almost zero net HR value (+0.006 K/d). The NMMB-BSC forecast model provided the dust mass concentration over Athens, while the air mass advection from the African to the European continent was simulated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model.

scholarly journals An outstanding Saharan dust event at Mt. Cimone (2165 m a.s.l., Italy) in March 2004

2015 ◽  
Vol 113 ◽  
pp. 223-235 ◽  
Author(s):  
Erika Brattich ◽  
Angelo Riccio ◽  
Laura Tositti ◽  
Paolo Cristofanelli ◽  
Paolo Bonasoni
Keyword(s):  
Saharan Dust ◽  
Dust Event

WRF-chem sensitivity to vertical resolution during a saharan dust event

2016 ◽  
Vol 94 ◽  
pp. 188-195 ◽  
Author(s):  
J.C. Teixeira ◽  
A.C. Carvalho ◽  
Paolo Tuccella ◽  
Gabriele Curci ◽  
A. Rocha
Keyword(s):  
Saharan Dust ◽  
Vertical Resolution ◽  
Dust Event

scholarly journals Synergetic monitoring of Saharan dust plumes and potential impact on surface: a case study of dust transport from Canary Islands to Iberian Peninsula

2011 ◽  
Vol 11 (7) ◽  
pp. 3067-3091 ◽  
Author(s):  
C. Córdoba-Jabonero ◽  
M. Sorribas ◽  
J. L. Guerrero-Rascado ◽  
J. A. Adame ◽  
Y. Hernández ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Particle Deposition ◽  
Ground Level ◽  
In Situ Measurements ◽  
Saharan Dust ◽  
Dust Transport ◽  
Air Masses ◽  
Potential Impact

Abstract. The synergetic use of meteorological information, remote sensing both ground-based active (lidar) and passive (sun-photometry) techniques together with backtrajectory analysis and in-situ measurements is devoted to the characterization of dust intrusions. A case study of air masses advected from the Saharan region to the Canary Islands and the Iberian Peninsula, located relatively close and far away from the dust sources, respectively, was considered for this purpose. The observations were performed over three Spanish geographically strategic stations within the dust-influenced area along a common dust plume pathway monitored from 11 to 19 of March 2008. A 4-day long dust event (13–16 March) over the Santa Cruz de Tenerife Observatory (SCO), and a linked short 1-day dust episode (14 March) in the Southern Iberian Peninsula over the Atmospheric Sounding Station "El Arenosillo" (ARN) and the Granada station (GRA) were detected. Meteorological conditions favoured the dust plume transport over the area under study. Backtrajectory analysis clearly revealed the Saharan region as the source of the dust intrusion. Under the Saharan air masses influence, AERONET Aerosol Optical Depth at 500 nm (AOD500) ranged from 0.3 to 0.6 and Ångström Exponent at 440/675 nm wavelength pair (AE440/675) was lower than 0.5, indicating a high loading and predominance of coarse particles during those dusty events. Lidar observations characterized their vertical layering structure, identifying different aerosol contributions depending on altitude. In particular, the 3-km height dust layer transported from the Saharan region and observed over SCO site was later on detected at ARN and GRA stations. No significant differences were found in the lidar (extinction-to-backscatter) ratio (LR) estimation for that dust plume over all stations when a suitable aerosol scenario for lidar data retrieval is selected. Lidar-retrieved LR values of 60–70 sr were obtained during the main dust episodes. These similar LR values found in all the stations suggest that dust properties were kept nearly unchanged in the course of its medium-range transport. In addition, the potential impact on surface of that Saharan dust intrusion over the Iberian Peninsula was evaluated by means of ground-level in-situ measurements for particle deposition assessment together with backtrajectory analysis. However, no connection between those dust plumes and the particle sedimentation registered at ground level is found. Differences on particle deposition processes observed in both Southern Iberian Peninsula sites are due to the particular dust transport pattern occurred over each station. Discrepancies between columnar-integrated and ground-level in-situ measurements show a clear dependence on height of the dust particle size distribution. Then, further vertical size-resolved observations are needed for evaluation of the impact on surface of the Saharan dust arrival to the Iberian Peninsula.

scholarly journals Transport of Saharan dust from the Bodélé Depression to the Amazon Basin: a case study

2010 ◽  
Vol 10 (2) ◽  
pp. 4345-4372 ◽  
Author(s):  
Y. Ben-Ami ◽  
I. Koren ◽  
Y. Rudich ◽  
P. Artaxo ◽  
S. T. Martin ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Amazon Basin ◽  
Marine Boundary Layer ◽  
Average Concentration ◽  
Saharan Dust ◽  
Aerosol Layer ◽  
Amazon Forest ◽  
Close Link ◽  
Bodele Depression

Abstract. Through long-range transport of dust, the Sahara desert supplies essential minerals to the Amazon rain forest. Since Saharan dust reaches South America mostly during the Northern Hemisphere winter, the dust sources active during winter are the main contributors to the forest. Given that the Bodélé depression area in Southwestern Chad is the main winter dust source, a close link is expected between the Bodélé emission patterns and volumes and the mineral supply flux to the Amazon. Until now, the particular link between the Bodélé and the Amazon forest was based on sparse satellite measurements and modeling studies. In this study, we combine a detailed analysis of space-borne and ground data with reanalysis model data and surface measurements taken in the Central Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08) in order to explore the validity and the nature of the proposed link between the Bodélé depression and the Amazon forest. This case study follows the dust events of 11–16 and 18–27 February 2008, from the emission in the Bodélé over West Africa, the crossing of the Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days after the emission. The dust was lifted by surface winds stronger than 14 m s−1, usually starting early in the morning. The lofted dust mixed with biomass burning aerosols over Nigeria, was transported over the Atlantic Ocean, and arrived over the South American continent. The top of the aerosol layer reached above 3 km, and the bottom merged with the marine boundary layer. The arrival of the dusty air parcel over the Amazon forest increased the average concentration of aerosol crustal elements by an order of magnitude.

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