Spatial Distribution of NO2 Concentration in Southeastern Region of Nigeria

The aim of this study is to examine the characteristics of the tropospheric Nitrogen Dioxide (NO2) concentrations over the five states of South Eastern Nigeria retrieved from Ozone Monitoring Instrument (OMI) data from 2010 – 2015. The mean concentration ranges from molecules/cm2 in Abakaliki (with the least commercial, industrial and vehicle activities) to in Aba, the industrial and commercial centre with coefficients of variation of 17.7% and 15.8% respectively. Results using non-parametric Mann-Kendall (MK) tests show a significant (p < 0.05) increasing levels of NO2 columns in the region. For each of the seven studied cities, there is a significant seasonal cycle of NO2 columns. NO2 maximum was observed in dry (harmattan) season (December – March) and minimum in wet (rainy) season (May, June, October). On the average, the annual change rate for the entire Southeast was 1.72% while the 5% uncertainty interval for the region was , which indicates a highly polluted region.