Trends in Saharan dust and tropical Atlantic climate during 1980–2006

2008 ◽  
Vol 35 (20) ◽  
Author(s):  
Gregory R. Foltz ◽  
Michael J. McPhaden
Keyword(s):  
Saharan Dust ◽  
Tropical Atlantic

scholarly journals An additional low layer transport of Sahelian and Saharan dust over the north-eastern Tropical Atlantic

1995 ◽  
Vol 22 (23) ◽  
pp. 3191-3194 ◽  
Author(s):  
I. Chiapello ◽  
G. Bergametti ◽  
L. Gomes ◽  
B. Chatenet ◽  
F. Dulac ◽  
...  
Keyword(s):  
Saharan Dust ◽  
Tropical Atlantic ◽  
The North ◽  
North Eastern

scholarly journals Profiling of Saharan dust from the Caribbean to western Africa – Part 2: Shipborne lidar measurements versus forecasts

2017 ◽  
Vol 17 (24) ◽  
pp. 14987-15006 ◽  
Author(s):  
Albert Ansmann ◽  
Franziska Rittmeister ◽  
Ronny Engelmann ◽  
Sara Basart ◽  
Oriol Jorba ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Dust Emission ◽  
Saharan Dust ◽  
Light Extinction ◽  
Tropical Atlantic ◽  
Fine Dust ◽  
Anthropogenic Aerosol ◽  
Dust Transport ◽  
Western Africa ◽  
Dust Sources

Abstract. A unique 4-week ship cruise from Guadeloupe to Cabo Verde in April–May 2013 see part 1, Rittmeister et al. (2017) is used for an in-depth comparison of dust profiles observed with a polarization/Raman lidar aboard the German research vessel Meteor over the remote tropical Atlantic and respective dust forecasts of a regional (SKIRON) and two global atmospheric (dust) transport models (NMMB/BSC-Dust, MACC/CAMS). New options of model–observation comparisons are presented. We analyze how well the modeled fine dust (submicrometer particles) and coarse dust contributions to light extinction and mass concentration match respective lidar observations, and to what extent models, adjusted to aerosol optical thickness observations, are able to reproduce the observed layering and mixing of dust and non-dust (mostly marine) aerosol components over the remote tropical Atlantic. Based on the coherent set of dust profiles at well-defined distances from Africa (without any disturbance by anthropogenic aerosol sources over the ocean), we investigate how accurately the models handle dust removal at distances of 1500 km to more than 5000 km west of the Saharan dust source regions. It was found that (a) dust predictions are of acceptable quality for the first several days after dust emission up to 2000 km west of the African continent, (b) the removal of dust from the atmosphere is too strong for large transport paths in the global models, and (c) the simulated fine-to-coarse dust ratio (in terms of mass concentration and light extinction) is too high in the models compared to the observations. This deviation occurs initially close to the dust sources and then increases with distance from Africa and thus points to an overestimation of fine dust emission in the models.

scholarly journals Profiling of Saharan dust from the Caribbean to West Africa, Part 2: Shipborne lidar measurements versus forecasts

2017 ◽  
Author(s):  
Albert Ansmann ◽  
Franziska Rittmeister ◽  
Ronny Engelmann ◽  
Sara Basart ◽  
Angela Benedetti ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Dust Emission ◽  
Saharan Dust ◽  
Light Extinction ◽  
Tropical Atlantic ◽  
Anthropogenic Aerosol ◽  
Dust Transport ◽  
Source Regions ◽  
Dust Sources ◽  
Lidar Measurements

Abstract. A unique 4-week ship cruise from Guadeloupe to Cabo Verde in April–May 2013 (see part 1, Rittmeister et al., 2017) is used for an in-depth comparison of dust profiles observed with a polarization/Raman lidar aboard the German research vessel Meteor over the remote tropical Atlantic and respective dust forecasts of a regional (SKIRON) and two global atmospheric (dust) transport models (NMMB/BSC-Dust, MACC/CAMS). New options of model-observation comparisons are presented. We analyze how well the modeled fine dust (submicrometer particles) and coarse dust contributions to light extinction and mass concentration match respective lidar observations, and to what extent models, adjusted to aerosol optical thickness observations, are able to reproduce the observed layering and mixing of dust and non-dust (mostly marine) aerosol components over the remote tropical Atlantic. Based on the coherent set of dust profiles at well defined distances from Africa (without any disturbance by anthropogenic aerosol sources over the ocean) we investigate how accurately the models handle dust removal at distances of 1500 km to more than 5000 km west of the Saharan dust source regions. It was found that (a) dust predictions are of acceptable quality for the first several days after dust emission up to 2000 km west of the African continent, (b) the removal of dust from the atmosphere is too strong for large transport paths in the global models, and (c) the simulated fine-to-coarse dust ratio (in terms of mass concentration and light extinction) is too high in the models compared to the observations. This deviation is already given close to the dust sources and then increases with distance from Africa.

scholarly journals Influence of Saharan dust on Atlantic tropical cyclones

2020 ◽  
Author(s):  
Zhenxi Zhang ◽  
Wen Zhou
Keyword(s):  
Tropical Cyclones ◽  
North Atlantic ◽  
Radiative Forcing ◽  
Saharan Dust ◽  
Tropical Atlantic ◽  
Atmospheric Moisture ◽  
The North ◽  
The North Atlantic ◽  
Atlantic Itcz ◽  
Atlantic Tropical Cyclone

Abstract. The influence of Saharan dust outbreaks on summertime Atlantic tropical cyclone (TC) activity is explored using continuous atmospheric reanalysis products and TC track data from 1980 to 2019. Analyses reveal that the Saharan dust plume over the tropical Atlantic can affect TC activity by affecting the atmospheric hydrology and radiation absorbed by the earth's surface, which can be classified into three mechanisms. (1) A strong Saharan dust plume indirectly induces the reduction of atmospheric moisture, which further suppresses TC track, number of TC days, and intensity, with the influence covering the whole tropical Atlantic. (2) A strong Saharan dust plume enhances atmospheric moisture just along the North Atlantic ITCZ through the dust microphysical effect, which further promotes TC activity along 10º N latitude in June. (3) The climatological influence of dust on TC activity is caused by the strong radiative forcing of Saharan dust over the eastern tropical Atlantic in June, which produces an evident reduction in SST and lessens the duration and intensity of regional TC activity in June, according to the 40-yr average from 1980 to 2019.

scholarly journals Identifying Source Region Elemental Indicators in Aged Saharan Dust Plumes Over the Tropical Atlantic

2021 ◽  
Author(s):  
Daniel E. Yeager ◽  
Vernon R. Morris
Keyword(s):  
Atlantic Ocean ◽  
Source Region ◽  
Dust Aerosol ◽  
Saharan Dust ◽  
Back Trajectory ◽  
Tropical Atlantic ◽  
Aerosol Composition ◽  
Western Sahara ◽  
Ocean Science ◽  
Dust Events

Abstract. This work examines the spatial dependency of Saharan dust aerosol composition over the Tropical Atlantic Ocean using observations collected during the 2015 Aerosols and Ocean Science Expedition (AEROSE). Regionally specific elemental indicators remain detectable in the dust samples collected along the Saharan air layer trajectory far into the Tropical Atlantic marine boundary layer. Saharan dust transport characteristics and elemental composition were determined by Inductively Coupled Plasma Mass Spectrometric (ICP-MS) analysis of airborne dust samples, ship-based radiometry, satellite aerosol retrievals, and atmospheric back-trajectory analysis. Three strong dust events (SDEs) and two trace dust events (TDEs) were detected during the campaign. The associated mineral dust arrived from potentially 7 different north African countries within 5 to 15 days of emission, according to transport analysis. Peak Na / Al and Ca / Al ratios (>1 and >1.5, respectively) in dust samples were traced to northern Saharan source regions in Western Sahara and Libya. In contrast, peak Fe / Al ratios (0.4–0.8) were traced to surface sources in southern Saharan regions in central Mauritania. We observe the highest ratios of (3–10) at sampling latitudes north of 15N in the Atlantic. Additionally, the sub-micron fraction of dust particulate settling over the Atlantic showed significant temporal and spatial variability, with coarse-fine Al ratios (at 0.8 microns) of 1.05, 0.65, and 0.95 for SDE1 (11/21–23), SDE2 (11/25–26), and SDE3 (11/28), respectively. This was consistent with elemental concentrations of Ca, Na, K, Ti, and Sr, per Al, that exhibited coarser size tendencies per dust event. These observations could validate spatially-sensitive aerosol models by predicting dust aerosol abundance and composition within the tropical Atlantic. Such predictions are critical towards understanding Saharan dust effects on regional climate, Atlantic Ocean biogeochemistry, satellite observations, and air quality modeling.

scholarly journals Saharan dust as a causal factor of hemispheric asymmetry in aerosols and cloud cover over the tropical Atlantic Ocean

2015 ◽  
Vol 36 (13) ◽  
pp. 3423-3445 ◽  
Author(s):  
Pavel Kishcha ◽  
Arlindo da Silva ◽  
Boris Starobinets ◽  
Charles Long ◽  
Olga Kalashnikova ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Cloud Cover ◽  
Hemispheric Asymmetry ◽  
Causal Factor ◽  
Saharan Dust ◽  
Tropical Atlantic ◽  
Tropical Atlantic Ocean
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