In a recent study published in the journal ‘Discover Geoscience’ (which translates to ‘Entdecke Geowissenschaften’ in German), researchers have shed light on the long-term trends and seasonal variations of fine particulate matter (PM2.5) and its components over sub-Saharan West Africa. The research, led by Olusegun G. Fawole from the School of the Environment and Life Sciences at the University of Portsmouth, offers valuable insights into how these atmospheric aerosols influence climatic conditions and meteorological variables in the region.
The study, which spans a 30-year period, reveals that the West African Monsoon (WAM) plays a significant role in the variability of PM2.5 concentrations. During the onset and peak of the WAM, particularly in the months of March to May (MAM) and June to August (JJA), sulfate (SO4) and sea salt levels have shown a marked increase around the coastal areas of the Gulf of Guinea and the Sahara Desert, respectively. This seasonal variation is crucial for understanding the impact of aerosols on climate and air quality.
One of the key findings of the study is the significant increase in the carbon content of atmospheric aerosols, specifically black carbon (BC) and organic carbon (OC), which has risen by 30–70% over the past three decades. This increase is particularly notable between February and October, coinciding with the intense biomass burning season in Central and Southern Africa. As Fawole explains, “These findings give some insight into changes in climatic conditions and the variability of atmospheric variables, both of which are of great importance to pollution modeling, climate modelers, and policy makers.”
For the maritime sector, understanding these trends and variations is essential for several reasons. Shipping routes and port operations can be significantly affected by changes in atmospheric conditions. Increased levels of PM2.5 and its components can lead to reduced visibility, which can impact navigation and safety at sea. Additionally, the deposition of these particles on ships and port infrastructure can lead to increased maintenance costs and potential health risks for crew members and port workers.
Moreover, the study’s findings can inform policy decisions aimed at reducing emissions and improving air quality in the region. Maritime industries can play a role in this by adopting cleaner fuels and technologies that minimize their contribution to atmospheric pollution. As Fawole notes, “An in-depth and adequate knowledge of the variability and evolution of atmospheric aerosol and its components would engender accurate and robust research on the contribution of these aerosols to climate conditions and variability of atmospheric variables.”
In summary, the research published in ‘Discover Geoscience’ highlights the importance of understanding the long-term trends and seasonal variations of PM2.5 and its components in sub-Saharan West Africa. For the maritime sector, this knowledge can help mitigate the impacts of atmospheric aerosols on operations and infrastructure, while also contributing to broader efforts to improve air quality and combat climate change.