Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season

The terrain surrounding the Sahara desert is formed by some mountains ranges, as the Atlas mountain system in the northern edge of the desert and the Hoggar Mountains in Southern Algeria. Such orography, jointly with atmospheric circulation, plays an important role in the mobilization and transport of desert dust over medium and large distances. This study explores the interaction between complex terrain and atmospheric circulation in order to better understand an exceptional desert dust outbreak affecting Portugal in February 2017. The Meso-NH model is able to represent the atmospheric motions in different scales, and has been implemented with a rather complete parametrization package of physical processes in the atmosphere. The capability of the model to simulate dust emission is also explored. The on-line dust emission parametrization type is taken from the distribution of emitted dust of SURFEX with no need to use chemistry to activate dusts. A set of two simulations was performed for the period between 16 February at 0000 UTC to 24 February 1200 UTC, with the Meso-NH model configured in a single domain at 10 km horizontal resolution and 300x360 grid points. The experiments were defined as a) control experiment (CTRL), and b) dust experiment (DUST). From the large domain simulations, it was possible to assess the source of dust and its mobilization over Western Sahara desert, namely over the Northern part of Mauritania and Mali and Eastern part of Algeria. The formation of a cyclonic circulation at the surface favoured the dust uplifting. Such a surface low merged with a cut-off low that moved southward over the Iberian Peninsula and remained centred in the north of Morocco. Such pattern intensified the northward flow found at 700 hPa toward the Atlas Mountains range, inducing the dust transport above 3 km altitude. As expected, the simulations showed the ability to assess important details about the atmospheric circulation not resolved by low density of observations over the domain considered. Furthermore, the simulations were able to show the way that the atmospheric ingredients were brought together to produce the exceptional transport of desert dust toward Portugal. The orographic effects playing an important role in dust mobilization (convergence and cyclogenesis at the surface) and atmospheric circulation to the maintenance of the dust transport have been highlighted. Such event were responsible for the transport of high amount of dust toward the Iberian Peninsula.

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Analysis of Aeronet Extended Wavelength Retrievals of Aerosol Absorption Parameters Including 380 nm and 500 nm for Detection of Brown Carbon in Biomass Burning and Iron Oxides in Desert Dust

10.1109/igarss47720.2021.9553387 ◽

2021 ◽

Author(s):

Thomas F. Eck ◽

Brent N. Holben ◽

Alexander Sinyuk ◽

David M. Giles ◽

Antti Arola ◽

...

Keyword(s):

Iron Oxides ◽

Biomass Burning ◽

Brown Carbon ◽

Desert Dust ◽

Aerosol Absorption

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Characteristics of carbonaceous aerosols derived from long-term high-resolution measurements at a high-altitude site in the central Himalayas: radiative forcing estimates and role of meteorology and biomass burning

Environmental Science and Pollution Research ◽

10.1007/s11356-020-11579-1 ◽

2020 ◽

Author(s):

Priyanka Srivastava ◽

Manish Naja

Keyword(s):

High Resolution ◽

High Altitude ◽

Biomass Burning ◽

Radiative Forcing ◽

Carbonaceous Aerosols ◽

Central Himalayas

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Aerosol climatology over Nile Delta based on MODIS, MISR and OMI satellite data

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-10637-2011 ◽

2011 ◽

Vol 11 (20) ◽

pp. 10637-10648 ◽

Cited By ~ 37

Author(s):

H. S. Marey ◽

J. C. Gille ◽

H. M. El-Askary ◽

E. A. Shalaby ◽

M. E. El-Raey

Keyword(s):

Air Pollution ◽

Satellite Data ◽

Nile Delta ◽

Complex Mixture ◽

Spherical Particles ◽

Medium Size ◽

Delta Region ◽

Fall Season ◽

Mean Values ◽

Desert Dust

Abstract. Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the "black cloud" during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr period from 2000–2009. Significant monthly variability is observed in the AOD with maxima in April or May (~0.5) and October (~0.45), and a minimum in December and January (~0.2). Monthly mean values of UV Aerosol Index (UVAI) retrieved by the Ozone Monitoring Instrument (OMI) for 4 yr (2005–2008) exhibit the same AOD pattern. The carbonaceous aerosols during the black cloud periods are confined to the planetary boundary layer (PBL), while dust aerosols exist over a wider range of altitudes, as shown by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) aerosol profiles. The monthly climatology of Multi-angle Imaging SpectroRadiometer (MISR) data show that the aerosols during the black cloud periods are spherical with a higher percentage of small and medium size particles, whereas the spring aerosols are mostly large non-spherical particles. All of the results show that the air quality in Cairo and the Nile delta region is subject to a complex mixture of air pollution types, especially in the fall season, when biomass burning contributes to a background of urban pollution and desert dust.

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Aerosols in the CALIOPE air quality modelling system: evaluation and analysis of PM levels, optical depths and chemical composition over Europe

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-3363-2012 ◽

2012 ◽

Vol 12 (7) ◽

pp. 3363-3392 ◽

Cited By ~ 48

Author(s):

S. Basart ◽

M. T. Pay ◽

O. Jorba ◽

C. Pérez ◽

P. Jiménez-Guerrero ◽

...

Keyword(s):

Air Quality ◽

Fine Fraction ◽

Ground Level ◽

Air Quality Modelling ◽

Aerosol Composition ◽

Dust Transport ◽

Desert Dust ◽

Po Valley ◽

Limit Value ◽

Modelling System

Abstract. The CALIOPE air quality modelling system is developed and applied to Europe with high spatial resolution (12 km × 12 km). The modelled daily-to-seasonal aerosol variability over Europe in 2004 is evaluated and analysed. Aerosols are estimated from two models, CMAQv4.5 (AERO4) and BSC-DREAM8b. CMAQv4.5 calculates biogenic, anthropogenic and sea salt aerosol and BSC-DREAM8b provides the natural mineral dust contribution from North African deserts. For the evaluation, we use daily PM10, PM2.5 and aerosol components data from 55 stations of the EMEP/CREATE network and total, coarse and fine aerosol optical depth (AOD) data from 35 stations of the AERONET sun photometer network. Annual correlations between modelled and observed values for PM10 and PM2.5 are 0.55 and 0.47, respectively. Correlations for total, coarse and fine AOD are 0.51, 0.63, and 0.53, respectively. The higher correlations of the PM10 and the coarse mode AOD are largely due to the accurate representation of the African dust influence in the forecasting system. Overall PM and AOD levels are underestimated. The evaluation of the aerosol components highlights underestimations in the fine fraction of carbonaceous matter (EC and OC) and secondary inorganic aerosols (SIA; i.e. nitrate, sulphate and ammonium). The scores of the bulk parameters are significantly improved after applying a simple model bias correction based on the observed aerosol composition. The simulated PM10 and AOD present maximum values over the industrialized and populated Po Valley and Benelux regions. SIA are dominant in the fine fraction representing up to 80% of the aerosol budget in latitudes north of 40° N. In southern Europe, high PM10 and AOD are linked to the desert dust transport from the Sahara which contributes up to 40% of the aerosol budget. Maximum seasonal ground-level concentrations (PM10 > 30 μg m−3) are found between spring and early autumn. We estimate that desert dust causes daily exceedances of the PM10 European air quality limit value (50 μg m−3) in large areas south of 45° N with more than 75 exceedances per year in the southernmost regions.

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Impact of long-range desert dust transport on hydrometeor formation over coastal East Asia

Advances in Atmospheric Sciences ◽

10.1007/s00376-016-6157-0 ◽

2016 ◽

Vol 34 (1) ◽

pp. 101-115 ◽

Cited By ~ 1

Author(s):

Zhenxi Zhang ◽

Wen Zhou ◽

Mark Wenig ◽

Liangui Yang

Keyword(s):

East Asia ◽

Long Range ◽

Dust Transport ◽

Desert Dust

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Evaluation of Atmospheric PCDD/Fs at Two High-Altitude Stations in Vietnam and Taiwan during Southeast Asia Biomass Burning

Aerosol and Air Quality Research ◽

10.4209/aaqr.2015.11.0653 ◽

2016 ◽

Vol 16 (11) ◽

pp. 2706-2715 ◽

Cited By ~ 6

Author(s):

Kai Hsien Chi ◽

Ngo Tuan Hung ◽

Chuan-Yao Lin ◽

Sheng-Hsiang Wang ◽

Chang-Feng Ou-Yang ◽

...

Keyword(s):

Southeast Asia ◽

High Altitude ◽

Biomass Burning

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Temporal and spectral variation of desert dust and biomass burning aerosol scenes from 1995–2000 using GOME

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-1321-2006 ◽

2006 ◽

Vol 6 (1) ◽

pp. 1321-1353 ◽

Cited By ~ 1

Author(s):

M. de Graaf ◽

P. Stammes ◽

I. Aben

Keyword(s):

Biomass Burning ◽

Near Infrared ◽

Spectral Variation ◽

Desert Dust ◽

Dust Aerosols ◽

Near Ir ◽

Biomass Burning Aerosol ◽

Absorbing Aerosols ◽

Aerosol Index

Abstract. Global Ozone Monitoring Experiment (GOME) Absorbing Aerosol Index (AAI) and AAI-related residue data were used to investigate areas with UV-absorbing aerosols. Time series of regionally averaged residues show the seasonal variation and trends of aerosols and clouds in climatologically important parts of the globe. GOME spectra were used to study scenes containing specific types of aerosols. AAI data are specifically sensitive to biomass burning aerosols (BBA) and desert dust aerosols (DDA). Areas where these aerosols are regularly found were analysed to find spectral fingerprints in the ultraviolet (UV), visible and near-infrared (near-IR), to establish an aerosol type classification of BBA and DDA. Spectral residues are different for BBA and DDA, but over deserts the surface albedo is dominant beyond the UV and spectral residues cannot be used over land. Over oceans, about half of the BBA scenes show a very high reflectance that is never observed for DDA scenes. However, in the case of low reflectance scenes BBA and DDA cannot be distinguished. This is in part due to the microphysical and optical properties of biomass burning aerosols, which are highly variable in time, making it difficult to specify them spectrally as one type. Because of their high hygroscopicity BBA are often found in the presence of clouds, which disturb the spectrum of the scenes. Desert dust aerosols are much less hygroscopic and behave spectrally more uniformly.

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African biomass burning is a substantial source of phosphorus deposition to the Amazon, Tropical Atlantic Ocean, and Southern Ocean

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1906091116 ◽

2019 ◽

Vol 116 (33) ◽

pp. 16216-16221 ◽

Cited By ~ 27

Author(s):

Anne E. Barkley ◽

Joseph M. Prospero ◽

Natalie Mahowald ◽

Douglas S. Hamilton ◽

Kimberly J. Popendorf ◽

...

Keyword(s):

Atlantic Ocean ◽

Biomass Burning ◽

Amazon Basin ◽

Transport Model ◽

Boreal Summer ◽

Tropical Atlantic ◽

Dust Transport ◽

Tropical Atlantic Ocean ◽

African Dust ◽

Soluble P

The deposition of phosphorus (P) from African dust is believed to play an important role in bolstering primary productivity in the Amazon Basin and Tropical Atlantic Ocean (TAO), leading to sequestration of carbon dioxide. However, there are few measurements of African dust in South America that can robustly test this hypothesis and even fewer measurements of soluble P, which is readily available for stimulating primary production in the ocean. To test this hypothesis, we measured total and soluble P in long-range transported aerosols collected in Cayenne, French Guiana, a TAO coastal site located at the northeastern edge of the Amazon. Our measurements confirm that in boreal spring when African dust transport is greatest, dust supplies the majority of P, of which 5% is soluble. In boreal fall, when dust transport is at an annual minimum, we measured unexpectedly high concentrations of soluble P, which we show is associated with the transport of biomass burning (BB) from southern Africa. Integrating our results into a chemical transport model, we show that African BB supplies up to half of the P deposited annually to the Amazon from transported African aerosol. This observational study links P-rich BB aerosols from Africa to enhanced P deposition in the Amazon. Contrary to current thought, we also show that African BB is a more important source of soluble P than dust to the TAO and oceans in the Southern Hemisphere and may be more important for marine productivity, particularly in boreal summer and fall.

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Climatology of dust deposition in the Adriatic Sea and biological response of Rogoznica Lake (central Adriatic)

10.5194/egusphere-egu21-5793 ◽

2021 ◽

Author(s):

Boris Mifka ◽

Irena Ciglenečki ◽

Maja Telišman Prtenjak

Keyword(s):

North Africa ◽

Adriatic Sea ◽

Biological Response ◽

Direct Consequence ◽

Reanalysis Data ◽

Dust Deposition ◽

Dust Transport ◽

Desert Dust ◽

Dust Sources ◽

Marine System

Airborne desert dust is one of the most abundant aerosols and an important factor in climate change. After deposition in the sea, mineral dust acts as the nutrient. In this study, the climatology of desert dust deposition in the Adriatic Sea was investigated with special reference to the possible source and mineralogical characteristics of transported dust from North Africa. The effect is particularly examined in unique, isolated marine system, Rogoznica Lake (RL; 43&#176; 32 &#8217;N, 15&#176; 58&#8217; E) through its biological response. For that purpose, the MERRA-2 reanalysis data for dust deposition in the period 1989- 2019 were used. Annual dust deposition cycle in the Adriatic Sea has maximum in spring and fall with stronger deposition in central and south. Wet deposition accounts for 63-92% of total deposition and 75% of data contains less than 1.5% of the mass. Intensity classes are defined for the remaining 25% and each refers to about 30% of the mass. On average, over 73 days per year is of weak, 14.6 of moderate, and 3.65 of extreme intensity, which varies spatially. In order to detect the specific synoptic patterns for the dust transport in relation to the dust sources activity and deposition in the Adriatic Sea, the EOF analysis on 850 hPa was utilized. Positive or negative mode phases correspond to deposition anomalies in the Adriatic Sea and can be related to particular dust sources in North Africa. Given the seasonal strong physicochemical stratification, relatively small volume, and only source of freshwater and nutrients through precipitation during stratification, the Rogoznica Lake proved ideal for monitoring desert dust deposition events, by monitoring nutrient concentration in the surface layer (0&#8211;2 m). For the 2000-2012 period no correlation with MERRA-2 deposition time series were found, but biological activity as a direct consequence of nutrient increase was observed during deposition events. Since the Adriatic Sea was proved to be phosphate (P) and iron (Fe) limited, the mineralogical database was used to estimate the amount of deposited P and Fe during intense deposition events.

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