Semidirect dynamical and radiative effect of North African dust transport on lower tropospheric clouds over the subtropical North Atlantic in CESM 1.0

Abstract. One of the most important factors that determine the transported dust effect on the atmosphere is its vertical distribution. In this study the vertical structure of North African dust and stratiform low clouds is analyzed over the Atlantic Ocean for the 2006–2007 boreal winter (December–February) and boreal summer of 2006 (June–August). By using the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) backscatter measurements over the dust routes, we describe the differences in dust transport between the seasons. We show a bi-modal distribution of the average dust plumes height in both seasons (it is less clear in the winter). The higher plume top height is 5.1±0.4 km, near the African coast line in the summer and 3.7±0.4 km in the winter. The lower plume merges with the marine boundary layer, in both seasons. Our study suggests that a significant part of the dust is transported near and within the marine boundary layer and interacts with low stratiform clouds.

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Characterizing the annual cycle of African dust transport to the Caribbean Basin and South America and its impact on the environment and air quality

Global Biogeochemical Cycles ◽

10.1002/2013gb004802 ◽

2014 ◽

Vol 28 (7) ◽

pp. 757-773 ◽

Cited By ~ 117

Author(s):

Joseph M. Prospero ◽

François-Xavier Collard ◽

Jack Molinié ◽

Alexis Jeannot

Keyword(s):

Air Quality ◽

South America ◽

Annual Cycle ◽

Caribbean Basin ◽

Dust Transport ◽

African Dust ◽

The Caribbean

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The Problem of Piracy in the Newfoundland Fishery in the Aftermath of the War of the Spanish Succession

War and Trade in Eighteenth-Century Newfoundland ◽

10.5949/liverpool/9781927869024.003.0004 ◽

2013 ◽

pp. 31-48

Author(s):

Olaf U. Janzen

Keyword(s):

Working Conditions ◽

North Atlantic ◽

Economic Recovery ◽

North African ◽

State Protection

This chapter explores the brief resurgence of piracy in Newfoundland between the years 1717 and 1725. It places the developments in Newfoundland within the context of North Atlantic piracy in the aftermath of the War of Spanish Succession, whilst linking the presence of pirates in Newfoundland to the working conditions of the Fishery. It details the fish trade’s vulnerability to piracy, particularly from North African ‘Sallee Rovers’; the increase in state protection; the differing approaches of Britain and France when dealing with piracy; and the difficult working conditions in the fishery and how that contributed to the recruitment of pirates. It concludes that once the Royal Navy’s presence in Newfoundland increased and the working conditions in the fishery eased during economic recovery, piracy was quick to disappear from the area.

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Saharan Dust Transport Over the North Atlantic Ocean and Mediterranean: An Overview

Environmental Science and Technology Library - The Impact of Desert Dust Across the Mediterranean ◽

10.1007/978-94-017-3354-0_13 ◽

1996 ◽

pp. 133-151 ◽

Cited By ~ 126

Author(s):

J. M. Prospero

Keyword(s):

Atlantic Ocean ◽

North Atlantic ◽

North Atlantic Ocean ◽

Saharan Dust ◽

Dust Transport ◽

The North ◽

The North Atlantic

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Three North African dust source areas and their geochemical fingerprint

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2020.116645 ◽

2021 ◽

Vol 554 ◽

pp. 116645

Author(s):

Amy M. Jewell ◽

Nick Drake ◽

Anya J. Crocker ◽

Natalie L. Bakker ◽

Tereza Kunkelova ◽

...

Keyword(s):

North African ◽

Dust Source ◽

Source Areas ◽

African Dust ◽

Geochemical Fingerprint

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North African dust transport toward the western Mediterranean basin: Atmospheric controls on dust source activation and transport pathways during June–July 2013

10.5194/acp-2016-497 ◽

2016 ◽

Author(s):

Kerstin Schepanski ◽

Marc Mallet ◽

Bernd Heinold ◽

Max Ulrich

Keyword(s):

Atmospheric Circulation ◽

Mediterranean Basin ◽

Dust Emission ◽

Western Mediterranean ◽

North African ◽

Atmospheric Dust ◽

Dust Source ◽

Dust Transport ◽

The Mediterranean ◽

Heat Low

Abstract. Dust transported from North African source region toward the Mediterranean basin and Europe is an ubiquitous phenomenon in the Mediterranean region. Winds formed by large-scale pressure gradients foster dust entrainment into the atmosphere over North African dust source regions and advection of dust downwind. The constellation of centers of high and low pressure determines wind speed and direction, and thus the chance for dust emission over Northern Africa and transport toward the Mediterranean. Here, we present characteristics of the atmospheric dust life-cycle determining dust transport toward the Mediterranean basin. Using the atmosphere-dust model COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdelling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model), a complementary analysis of dust source activation, emission fluxes, transport pathways, and deposition rates is provided with focus on the ChArMEx (Chemistry-Aerosol Mediterranean Experiment) special observation period in June and July 2013. Modes of atmospheric circulation, identified from empirical orthogonal function (EOF) analysis of the geopotential height at 850 hPa are used for investigating the characteristics of the atmospheric dust life-cycle regarding the atmospheric circulation over the Mediterranean. Two different phases are identified from the first EOF, which in total are explaining 45 % of the variance. They are characterized by the propagation of the subtropical ridge into the Mediterranean basin, the position of the Saharan heat low and the predominance Iberian heat low and discussed illustrating a dipole pattern for enhanced (reduced) dust emission fluxes, stronger (weaker) meridional dust transport, and consequent increased (decreased) atmospheric dust concentrations and deposition fluxes. In case of a predominant high pressure zone over the western and central Mediterranean (positive phase), a hot spot in dust emission flux is evident over the Grand Erg Occidental and reduced level of atmospheric dust loading occurs over the western Mediterranean basin. The meridional transport in northward direction is reduced due to prevailing northerly winds. In case of a predominant heat low trough linking the Iberian and the Sahara heat low (negative phase), meridional dust transport toward the western Mediterranean is increased due to prevailing southerly winds resulting into an enhanced atmospheric dust loading over the western Mediterranean. Altogether, results form this study illustrate the relevance of knowing dust source location in concert with atmospheric circulation. The study elaborates the question on the variability of dust transport toward the Mediterranean and Europe in dependence on the atmospheric circulation as a driver for dust emission and a determinant for dust transport routes, exemplarily for the two-month period June to July 2013. Ultimately, outcomes from this study contribute to the understanding of the variance in dust transport into a populated region.

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