Atmospheric controls on the annual cycle of North African dust

Engelstaedter, Sebastian; Washington, Richard

doi:10.1029/2006jd007195

Cited by 207 publications

(265 citation statements)

References 65 publications

(92 reference statements)

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“…Overall, studies estimate that the global dust emission varies by a factor of slightly more than two, although extreme values from 1,018 Tg year −1 (Miller et al 2004) to 3,000 Tg year −1 (Tegen and Fung 1994) have been established over the last two decades (Engelstaedter et al 2006). Estimates of the contribution of the different source areas also vary by study and are more difficult to make, especially as each source area follows a distinct seasonal cycle (Engelstaedter and Washington 2007). However, studies addressing these problems all agree that North Africa is the main source area (over 50 %) (see, e.g.…”

Section: Introductionmentioning

confidence: 99%

Desert dust impacts on human health: an alarming worldwide reality and a need for studies in West Africa

et al. 2012

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High desert dust concentrations raise concerns about adverse health effects on human populations. Based on a systematic literature review, this paper aims to learn more about the relationship between desert dust and human health in the world and to analyse the place of West Africa as a study area of interest. Papers focussing on the potential relationship between dust and health and showing quantitative analyses, published between January 1999 and September 2011, were identified using the ISI Web of Knowledge database (N050). A number of adverse health effects, including respiratory, cardiovascular and cardiopulmonary diseases, are associated with dust. This survey highlights obvious dust impacts on human health independently of the study area, health outcomes and method. Moreover, it reveals an imbalance between the areas most exposed to dust and the areas most studied in terms of health effects. None of these studies has been conducted in West Africa, despite the proximity of the Sahara, which produces about half of the yearly global mineral dust. In view of the alarming results in many parts of the world (Asia, Europe, America), this paper concludes by stressing the importance of carrying out impact studies of Saharan dust in West Africa, where dust events are more frequent and intense than anywhere else.

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Section: Introductionmentioning

confidence: 99%

Desert dust impacts on human health: an alarming worldwide reality and a need for studies in West Africa

et al. 2012

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“…North African dust emissions and transport have been shown to be highly variable in time and space (e.g. Prospero et al, 2002;Engelstaedter and Washington, 2007). Failure to represent variability in aerosol concentrations over the Sahara can account for significant errors in model representation of the Saharan heat low thermodynamics and pressures (Haywood et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Multi‐platform observations of a springtime case of Bodélé and Sudan dust emission, transport and scavenging over West Africa

Flamant¹,

Lavaysse²,

Todd³

et al. 2009

Quart J Royal Meteoro Soc

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ABSTRACT:The structure of the Saharan air layer over Niger and Benin during a major springtime dust event from the Bodélé region and Sudan is investigated using airborne lidar and dropsonde measurements. Aircraft operations were conducted on 13 and 14 June 2006, within the framework of the African Monsoon Multidisciplinary Analysis Special Observing Period. Complementary ground-based and satellite observations, as well as European Centre for Medium-range Weather Forecasts analyses are used to investigate the regional aspects of emission, transport and deposition in the period from 9 to 14 June 2006, to provide a framework for the interpretation of the airborne measurements. The study details the transport patterns of dust from eastern Saharan sources towards the southwest in the springtime, and highlights the role of the intertropical discontinuity and the Darfur mountains in injecting the aerosols from Bodélé and Sudan, respectively, over the monsoon flow, and in the African easterly jet (AEJ) region. It also illustrates the impact of the daily variability of the emissions in the source regions on the dust load advected westward by the AEJ and observed over Benin. The impact of a mesoscale convective system (MCS) on the dust load and vertical distribution observed over Benin and southern Niger was also investigated, nearly 12 hours after its passage over Benin. The only discernible impact on the dust distribution is observed to be associated with widespread subsidence in the wake of the MCS, over northern Benin and Niger. Wet scavenging related to convective or stratiform rain could not be observed, as processed air masses were replaced by fresh dust transported in the upper Saharan air layer by the AEJ. Over southern Benin, the dust distribution appeared to be mostly controlled by processes affecting the planetary boundary layer upstream, i.e. over Nigeria or Chad. Because springtime dust from remote eastern sources (such as observed in this case) is mainly transported into the AEJ, it could impact on the radiation budget in the AEJ region, thereby possibly modifying the West African weather at the synoptic scale. Copyright

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“…The West Saharan source is one of the world's largest sources of mineral dust, with an annual peak of emission during summer (Engelstaedter and Washington, 2007). Dust emitted from desert regions and transported in the atmosphere is recognized as an important component of the Earth's climate system, scattering incoming solar radiation and absorbing and emitting infrared radiation.…”

Section: Introductionmentioning

confidence: 99%

Dust impact on the West African heat low in summertime

Lavaysse

Chaboureau

Flamant

2011

Quart J Royal Meteoro Soc

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) is investigated, with convective rainfall and dust bursts being observed over the Sahel at the beginning and end of the episode. Three Meso-NH simulations were designed which differed in their dust representation. All the simulations capture the variation in the WAHL intensity well, including the simulation without any dust effects. This shows the primary role of largescale forcing on the WAHL pulsation. In spite of additional daytime heating and night-time cooling effects over the Sahara, the simulation with dust climatology resembles the simulation without any dust effects. In contrast, the simulation using a prognostic dust scheme enhances alternating northward advection of warm and dry air and southward advection of cold and wet air associated with the propagation of an African easterly wave, leading to a strengthening of the WAHL variabilities. This study highlights two effects of dust on the WAHL over the Sahara: a so-called direct effect associated with dust radiative heating, which increases the WAHL thickness, and a so-called indirect effect that intensifies both the African easterly jet and a related African easterly wave.

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Atmospheric controls on the annual cycle of North African dust

Cited by 207 publications

References 65 publications

Desert dust impacts on human health: an alarming worldwide reality and a need for studies in West Africa

Desert dust impacts on human health: an alarming worldwide reality and a need for studies in West Africa

Multi‐platform observations of a springtime case of Bodélé and Sudan dust emission, transport and scavenging over West Africa

Dust impact on the West African heat low in summertime

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