INVESTIGATION OF THE TRANSPORT PROFILE AND DISPERSION OF ATMOSPHERIC AEROSOL OVER THE COASTAL REGION OF LAGOS

INVESTIGATION OF THE TRANSPORT PROFILE AND DISPERSION OF ATMOSPHERIC AEROSOL OVER THE COASTAL REGION OF LAGOS

ABSTRACT

This study investigates the transport profile and source-sink system for sea salt aerosol over the coastal region of Lagos. The study utilized the GPS information of the study locations to simulate meteorological variables over the area from the Air Resource Laboratory (ARL) website, The ARL/GFS model was used to determine the wind rose information between 8th and 14th of June, 2017. In addition, backward air mass trajectories were determined at various heights of 0m, 1000m and 2000m above ground level (AGL) for aerosol transport patterns as well as concentration dispersion using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. The result showed that aerosols are of sea salt origin which evolved from the sea of the Atlantic Ocean. The maximum wind speed for the period considered from 8th to 14th June 2017 was 4 to < 7 m/s range in SW direction and as such complete calmness was not observed during the period under consideration. The highest frequency of wind blown was 56% which implies that 56% of atmospheric sea salt aerosol were
transported during the study period. The backward concentration trajectory indicated that the maximum aerosol pollution reaching Lagos was 2.1 x 10-10 mg/m3 which were from the Atlantic Ocean and the minimum was about 5.0 x 10-16 mg/m3. Since these pollutants are most likely sea salts which are highly corrosive, adequate corrosion protection is recommended.