The Relationship Between Coastal West African Dust Level and Caribbean Island Dust

Abstract

Desert dust coming from North African sources is a major phenomenon of the atmosphere related to its impact on the earth climate and human health. A great part of this particle product is transferred in a westward flux, over the Atlantic Ocean in form of outbreaks. Depending on the season, transport conditions and meteorological configuration along the pathway, high dust concentrations can reach either the northeast coast of South America or the islands of the Caribbean region. Their arrival corresponds with bad local air quality and numerous admittances into hospital emergency rooms. The control of health risk requires a dust-level forecast using satellite, model and ground measurements data. In this study, we investigate a correlation between PM10 measurements performed in 2015 by air quality networks at two sites, one in Dakar located on the West African coast and the other in Guadeloupe, a French Caribbean Island. The PM10 dust concentrations for both sites have been obtained using the same certified instruments (TEOM). Only Guadeloupe dust events presenting a daily mean PM10 of up to 35 µg/m 3 with back trajectories crossing in the vicinity of Dakar and verifying trajectories coming from Dakar, crossing close to Guadeloupe, have been taken into account. An air masses transport delay deduced by the HYSPLIT trajectory model was applied and a non-correlation between the two sites PM10 (correlation coefficient R = 0.3) was observed. Using the same trajectories and back trajectories, proximity conditions and HYSPLIT delay, the two sites' Aeronet photometric measurements (AOT1020) have been compared. A good correlation confirmed by a correlation coefficient, R = 0.88, was obtained between the Dakar AOT 1020 and the Guadeloupe AOT 1020. On the twelve dusty days of 2015 within eligible conditions of the pathway, an 80% decrease of AOT1020 during the transfer over the Atlantic Ocean was found.

Impact of Saharan dust episodes on preterm births in Guadeloupe (French West Indies)

“…Guadeloupe can be considered a natural laboratory for disentangling the influence of desert dust natural pollution and anthropogenic pollution because according to Euphrasie-Clotilde et al ,14 on average, the concentration of anthropogenic pollution does not exceed 20 µg PM 10 /m 3 (despite some possible traffic-related pollution hot-spots). This study took advantage of the TIMOUN mother-child cohort, an archipelago-wide cohort, which collected information on potential maternal socioeconomic, behavioural and medical confounders at an early stage of pregnancy and therefore before outcomes occurred.…”

“…First, because of the absence of heavy industries and the year-round presence of trade winds (dispersing gaseous and chemical pollutants), anthropogenic particle pollution is low in this area (approximately 20 µg/m 3 ) 14. As a result, desert dust natural pollution is the main factor affecting PM 10 concentrations.…”

Multifractal characterisation of particulate matter (PM10) time series in the Caribbean basin using visibility graphs

“…In Caribbean region, air quality is highly deteriorated by the seasonal transport of African dust (Prospero et al, 2014). Contrary to urban areas highly industrialized in Europe, the United States or China, Caribbean islands exhibit low emission of particulate matter linked to anthropogenic pollution (Euphrasie-Clotilde et al, 2017;Plocoste et al, 2017Plocoste et al, , 2018. After the long-range transport from African coast to the Caribbean, i.e.…”

Spectral Observations of PM10 Fluctuations in the Hilbert Space

“…These strong oscillations observed in the middle of each year are attributed to PM10 related to dust outbreaks coming from the African coast from May to September [9]. For the rest of the year, PM10 is mainly generated by anthropogenic pollution [15].…”