Emissions from the Road Traffic of West African Cities: Assessment of Vehicle Fleet and Fuel Consumption

Doumbia, Madina; N’Datchoh, Evelyne Touré; Silué, Siélé; Yoboue, Véronique; Diedhiou, Arona; Hauhouot, Celestin A.

doi:10.3390/en11092300

Cited by 27 publications

(17 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Estimating fleet fuel economy of in-use vehicles is difficult as it varies with a number of other factors such as: the number of vehicles, fleet composition, vehicle characteristics, vehicle activities, fuel type and quality, congestion, driving style, road type, inspection and maintenance and degradation [16,17]. Prior studies have noted the importance of determining in-use fleet fuel economy especially with vehicles with accumulated mileage over 500,000 km [18,19]. USA and European environmental agencies factor in deterioration rates for vehicles under this mileage, but engines now last over 800,000 km before requiring the first rebuild of the engine [19].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Estimating On-Road Vehicle Fuel Economy in Africa: A Case Study Based on an Urban Transport Survey in Nairobi, Kenya

et al. 2019

View full text Add to dashboard Cite

In African cities like Nairobi, policies to improve vehicle fuel economy help to reduce greenhouse gas emissions and improve air quality, but lack of data is a major challenge. We present a methodology for estimating fuel economy in such cities. Vehicle characteristics and activity data, for both the formal fleet (private cars, motorcycles, light and heavy trucks) and informal fleet—minibuses (matatus), three-wheelers (tuktuks), goods vehicles (AskforTransport) and two-wheelers (bodabodas)—were collected and used to estimate fuel economy. Using two empirical models, general linear modelling (GLM) and artificial neural network (ANN), the relationships between vehicle characteristics for this fleet and fuel economy were analyzed for the first time. Fuel economy for bodabodas (4.6 ± 0.4 L/100 km), tuktuks (8.7 ± 4.6 L/100 km), passenger cars (22.8 ± 3.0 L/100 km), and matatus (33.1 ± 2.5 L/100 km) was found to be 2–3 times worse than in the countries these vehicles are imported from. The GLM provided the better estimate of predicted fuel economy based on vehicle characteristics. The analysis of survey data covering a large informal urban fleet helps meet the challenge of a lack of availability of vehicle data for emissions inventories. This may be useful to policy makers as emissions inventories underpin policy development to reduce emissions.

show abstract

Section: Introductionmentioning

confidence: 99%

“…18 variables identified from questionnaire survey data divided into two categories: numerical data and categorical data.…”

mentioning

confidence: 99%

Estimating On-Road Vehicle Fuel Economy in Africa: A Case Study Based on an Urban Transport Survey in Nairobi, Kenya

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Population growth, urbanization, and industrialization have led to increasing local emissions from various sources in addition to natural ones. For instance, coastal city development in SWA is leading to more traffic and fuel consumption (Doumbia et al, 2018). Anthropogenic emissions will continue increasing if no regulations are implemented (Liousse et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Cloud-venting induced downward mixing of the Central African biomass burning plume during the West Africa summer monsoon

Dajuma¹,

Ogunjobi²,

Vogel³

et al. 2019

Preprint

View full text Add to dashboard Cite

<p><strong>Abstract.</strong> Between June and September large amounts of biomass burning aerosol are released into the atmosphere from agricultural fires in Central and southern Africa. Recent studies have suggested that this plume is carried westward over the Atlantic Ocean at altitudes between 2 and 4&#8201;km and then northward with the monsoon flow at low levels to increase the atmospheric aerosol load over coastal cities in southern West Africa (SWA), thereby exacerbating air pollution problems. However, the processes by which these fire emissions are transported into the planetary boundary layer are still unclear. One potential factor is the large-scale subsidence related to the southern branch of the monsoon Hadley cell over the tropical Atlantic. Here we use convection-permitting model simulations with COSMO-ART to investigate for the first time to what extent mixing related to cloud venting contributes to the downward transport of the biomass burning plume. Based on a monthly climatology, model simulations compare satisfactory with wind fields from reanalysis data, cloud observations, and satellite retrieved CO mixing ratio. For a case study on 02 July 2016, modelled clouds and rainfall show overall good agreement with Spinning Enhanced Visible and InfraRed Imager (SEVIRI) cloud products and Global Precipitation Measurement Integrated Multi-satellite Retrievals (GPM-IMERG) rainfall estimates. However, there is a tendency for the model to produce too much clouds and rainfall over the Gulf of Guinea. Looking into the CO dispersion, used as an indicator for the biomass burning plume, we identified individual mixing events south of the coast of C&#244;te d&#8217;Ivoire due to midlevel convective clouds injecting parts of the biomass burning plume into the boundary layer. This cloud venting is modulated by the underlying sea surface temperatures. Idealized tracer experiments suggest that about 20&#8201;% of the CO mass from the 2&#8211;4&#8201;km layer are mixed below 1km within two days over the Gulf of Guinea. There is even stronger vertical mixing when the biomass burning plume reaches land due to daytime heating. In that case, the long-range transported biomass burning plume is mixed with local anthropogenic emissions. Future work should provide more robust statistics on the cloud venting effect over the Gulf of Guinea and include aspects of aerosol deposition.</p>

show abstract

“…Another recommendation is to promote the use of renewable energy, such as solar, for use in industries to reduce the consumption of fossils fuels, which are also exacerbating air pollution. With regard to transportation, the traffic fleet in the SWA region is dominated by old cars (Doumbia et al 2018). Regulations should be implemented to ban the use of old cars and to improve the public transportation systems in SWA, as both are major sources of pollutants.…”

Section: Adaptation and Mitigation Strategiesmentioning

confidence: 99%

Biomass Burning Effects on the Climate over Southern West Africa During the Summer Monsoon

Dajuma

Silué

Ogunjobi

et al. 2021

African Handbook of Climate Change Adaptation

View full text Add to dashboard Cite

Biomass Burning (BB) aerosol has attracted considerable attention due to its detrimental effects on climate through its radiative properties. In Africa, fire patterns are anticorrelated with the southward-northward movement of the intertropical convergence zone (ITCZ). Each year between June and September, BB occurs in the southern hemisphere of Africa, and aerosols are carried westward by the African Easterly Jet (AEJ) and advected at an altitude of between 2 and 4 km. Observations made during a field campaign of Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) (Knippertz et al., Bull Am Meteorol Soc 96:1451–1460, 2015) during the West African Monsoon (WAM) of June–July 2016 have revealed large quantities of BB aerosols in the Planetary Boundary Layer (PBL) over southern West Africa (SWA).This chapter examines the effects of the long-range transport of BB aerosols on the climate over SWA by means of a modeling study, and proposes several adaptation and mitigation strategies for policy makers regarding this phenomenon. A high-resolution regional climate model, known as the Consortium for Small-scale Modelling – Aerosols and Reactive Traces (COSMO-ART) gases, was used to conduct two set of experiments, with and without BB emissions, to quantify their impacts on the SWA atmosphere. Results revealed a reduction in surface shortwave (SW) radiation of up to about 6.5 W m−2 and an 11% increase of Cloud Droplets Number Concentration (CDNC) over the SWA domain. Also, an increase of 12.45% in Particulate Matter (PM25) surface concentration was observed in Abidjan (9.75 μg m−3), Accra (10.7 μg m−3), Cotonou (10.7 μg m−3), and Lagos (8 μg m−3), while the carbon monoxide (CO) mixing ratio increased by 90 ppb in Abidjan and Accra due to BB. Moreover, BB aerosols were found to contribute to a 70% increase of organic carbon (OC) below 1 km in the PBL, followed by black carbon (BC) with 24.5%. This work highlights the contribution of the long-range transport of BB pollutants to pollution levels in SWA and their effects on the climate. It focuses on a case study of 3 days (5–7 July 2016). However, more research on a longer time period is necessary to inform decision making properly.This study emphasizes the need to implement a long-term air quality monitoring system in SWA as a method of climate change mitigation and adaptation.

show abstract

Emissions from the Road Traffic of West African Cities: Assessment of Vehicle Fleet and Fuel Consumption

Cited by 27 publications

References 42 publications

Estimating On-Road Vehicle Fuel Economy in Africa: A Case Study Based on an Urban Transport Survey in Nairobi, Kenya

Estimating On-Road Vehicle Fuel Economy in Africa: A Case Study Based on an Urban Transport Survey in Nairobi, Kenya

Cloud-venting induced downward mixing of the Central African biomass burning plume during the West Africa summer monsoon

Biomass Burning Effects on the Climate over Southern West Africa During the Summer Monsoon

Contact Info

Product

Resources

About