Vertical distribution of Saharan dust based on 2.5-year model predictions

Alpert, Pinhas; Kishcha, Pavel; Shtivelman, Alon; Krichak, S. O.; Joseph, Joachim H.

doi:10.1016/j.atmosres.2003.11.001

Cited by 137 publications

(109 citation statements)

References 31 publications

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“…and the finest dust particles are raised up to 6 km from the surface level. A similar profile was obtained by Alpert et al (2004), who investigated the vertical profile of the Saharan dust at its source and as it gets transported to the eastern Mediterranean island of Lampedusa and Sede Boker in Israel. Sede Boker, being located at the northwestern side of the Arabian Peninsula, has similar climatological conditions to Kuwait and therefore the spring season witnesses the highest rate of blowing dust.…”

Section: Skiron Simulation Of the Dust Vertical Profilementioning

confidence: 83%

Aerosol's optical and physical characteristics and direct radiative forcing during a shamal dust storm, a case study

Saeed

Al‐Dashti²,

Spyrou

2014

Atmos. Chem. Phys.

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Abstract. Dust aerosols are analyzed for their optical and physical properties during an episode of a dust storm that blew over Kuwait on 26 March 2003 when the military Operation Iraqi Freedom was in full swing. The intensity of the dust storm was such that it left a thick suspension of dust throughout the following day, 27 March. The synoptic sequence leading to the dust storm and the associated wind fields are discussed. Ground-based measurements of aerosol optical thickness reached 3.617 and 4.17 on 26 and 27 March respectively while the Ångstrom coefficient, α 870/440 , dropped to −0.0234 and −0.0318. Particulate matter concentration of 10 µm diameter or less, PM 10 , peaked at 4800 µg m −3 during dust storm hours of 26 March. Moderate Resolution Imaging Spectroradiometer (MODIS) retrieved aerosol optical depth (AOD) by Deep Blue algorithm and Total Ozone Mapping Spectrometer (TOMS) aerosol index (AI) exhibited high values. Latitude-longitude maps of AOD and AI were used to deduce source regions of dust transport over Kuwait. The vertical profile of the dust layer was simulated using the SKIRON atmospheric model. Instantaneous net direct radiative forcing is calculated at top of atmosphere (TOA) and surface level. The thick dust layer of 26 March resulted in cooling the TOA by −60 Wm −2 and surface level by −175 Wm −2 for a surface albedo of 0.35. Slightly higher values were obtained for 27 March due to the increase in aerosol optical thickness. Radiative heating/cooling rates in the shortwave and longwave bands were also examined. Shortwave heating rate reached a maximum value of 2 K day −1 between 3 and 5 km, dropped to 1.5 K day −1 at 6 km and diminished at 8 km. Longwave radiation initially heated the lower atmosphere by a maximum value of 0.2 K day −1 at surface level, declined sharply at increasing altitude and diminished at 4 km. Above 4 km longwave radiation started to cool the atmosphere slightly reaching a maximum rate of −0.1 K day −1 at 6 km.

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Section: Skiron Simulation Of the Dust Vertical Profilementioning

confidence: 83%

Aerosol's optical and physical characteristics and direct radiative forcing during a shamal dust storm, a case study

Saeed

Al‐Dashti²,

Spyrou

2014

Atmos. Chem. Phys.

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“…The trajectories were 120 h (5 days backwards transport period) long. The three altitudes correspond to transport at surface, boundary layer height and free troposphere and are appropriate for identifying Saharan dust transport events over the Eastern Mediterranean, Greece and the greater area of Athens (Hamonou et al, 1999;Alpert et al, 2004;Papayannis et al, 2005;Papayannis et al, 2009). Also 3D trajectory data available from the Chemical Co-ordinating Centre of EMEP (EMEP/CCC) calculated using Flextra trajectory model every 6 h were retrieved.…”

Section: Identification Of Desert Dust Intrusion Events Coinciding Wimentioning

confidence: 99%

Identification of the Influence of African Dust on PM10 Concentrations at the Athens Air Quality Monitoring Network during the Period 2001-2010

Aleksandropoulou

Lazaridis

2013

Aerosol Air Qual. Res.

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The objective of this work was to identify Sahara dust intrusions and quantify their contribution to annual and daily PM 10 concentrations over the Athens Metropolitan Area (AMA) during the period 2001-2010. Additionally, extreme PM 10 values attributed to large forest fires and volcanic emissions or the synergy of the above with African dust intrusions have been identified. It was found that the concentrations of PM 10 during the period studied exceeded the European Union's Air Quality Standard (EU AQS) value at most of the traffic urban (TU) stations. Most of the extreme values were attributed to dust events or large forest fires. The contribution from African dust to PM 10 concentrations on days with events and exceedances of the EU AQS was approximately 50% at TU stations and 72% at the background suburban stations (BS). Most of the African dust events contributed about 5 μg/m 3 to 34 μg/m 3 to the daily PM 10 concentrations, whereas the average contribution to annual PM 10 concentrations was approximately 8.6 ± 1.8 μg/m 3 i.e., 22.2 ± 7.5%. During the decade, no clear interannual relationship was observed between the African dust contribution and the frequency and intensity of events. The more frequent and severe episodes occurred during spring, while less frequent and less severe episodes occurred during summer. After the extraction of the African dust load the annual and daily AQS was exceeded in 2010 at only one TU station. The average annual contribution of African dust to the exceedances was approximately 36% at TU stations and 58% at BS stations.

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“…These are often related to convective systems or the passages of cold fronts (Pye, 1987;Shao, 2000). Dust injected into high atmospheric levels of up to several kilometers can be transported over horizontal distances of thousands of kilometers in strong wind systems (Alpert et al, 2004).…”

Section: Dust Activationmentioning

confidence: 99%

A case of extreme particulate matter concentrations over Central Europe caused by dust emitted over the southern Ukraine

et al. 2008

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Abstract. On 24 March 2007, an extraordinary dust plume was observed in the Central European troposphere. Satellite observations revealed its origins in a dust storm in Southern Ukraine, where large amounts of soil were resuspended from dried-out farmlands at wind gusts up to 30 m s−1. Along the pathway of the plume, maximum particulate matter (PM10) mass concentrations between 200 and 1400 μg m−3 occurred in Slovakia, the Czech Republic, Poland, and Germany. Over Germany, the dust plume was characterised by a volume extinction coefficient up to 400 Mm−1 and a particle optical depth of 0.71 at wavelength 0.532 μm. In-situ size distribution measurements as well as the wavelength dependence of light extinction from lidar and Sun photometer measurements confirmed the presence of a coarse particle mode with diameters around 2–3 μm. Chemical particle analyses suggested a fraction of 75% crustal material in daily average PM10 and up to 85% in the coarser fraction PM10–2.5. Based on the particle characteristics as well as a lack of increased CO and CO2 levels, a significant impact of biomass burning was ruled out. The reasons for the high particle concentrations in the dust plume were twofold: First, dust was transported very rapidly into Central Europe in a boundary layer jet under dry conditions. Second, the dust plume was confined to a relatively stable boundary layer of 1.4–1.8 km height, and could therefore neither expand nor dilute efficiently. Our findings illustrate the capacity of combined in situ and remote sensing measurements to characterise large-scale dust plumes with a variety of aerosol parameters. Although such plumes from Southern Eurasia seem to occur rather infrequently in Central Europe, its unexpected features highlights the need to improve the description of dust emission, transport and transformation processes needs, particularly when facing the possible effects of further anthropogenic desertification and climate change.

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Vertical distribution of Saharan dust based on 2.5-year model predictions

Cited by 137 publications

References 31 publications

Aerosol's optical and physical characteristics and direct radiative forcing during a shamal dust storm, a case study

Aerosol's optical and physical characteristics and direct radiative forcing during a shamal dust storm, a case study

Identification of the Influence of African Dust on PM10 Concentrations at the Athens Air Quality Monitoring Network during the Period 2001-2010

A case of extreme particulate matter concentrations over Central Europe caused by dust emitted over the southern Ukraine

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