ANALYSIS OF TEMPORAL AND SPATIAL VARIABILITY OF GREENHOUSE GASES CONCENTRATION OVER NIGERIA

Abstract

This study examined the temporal and spatial variability of Greenhouse Gases concentration over Nigeria using downloaded data from the Macc-Reanalysis dataset which is a subset of the dataset of European Center for Medium-Range Weather Forecasts. The re-analysis datasets used in this research were Total Column Ozone, Total Column Methane, Total Column Carbon Monoxide, Total Column Nitrogen Oxide and Total Column Water vapor gridded at 0.50 x 0.05 in space and spanned from 2003 to 2012 over Nigerian domain. Time series analysis was used to determine the temporal variability of greenhouse gases concentration which was measured at successive equally-spaced time intervals such as daily, weekly, monthly, and interannual time scales. Time series component that were examined in the present study was the daily variation and was sought to identify trends in the given datasets. The monthly concentration for the period of study was plotted using Linux-based Ferret visual software in order to examine the spatial distribution of the greenhouse gases. In this study, significant observations emerged: a moderately positively skewed and less peaked platykurtic curve for ozone, higher positively skewed with more peaked leptokurtic curve for methane, moderately positively skewed with less peaked platykurtic curve for carbon monoxide, high positively skewed with less peaked platykurtic curve for nitrogen oxide and a moderately normal skewed and less peaked platicurtic curve with negative value for water vapor. General peaked distribution in all cases (positive coefficient of skewness) with most gases having a distribution with asymmetric tail extending towards more positive values as evidence in the positive coefficient of kurtosis except for water vapor which extends towards more negative value as indicated in the negative coefficient of kurtosis. Greenhouse Gases were observed to be significant at 95% and 99% confidence level in most parts of the country. The anomaly over the study area revealed that there was a composite nature in which some of dry seasons were mixed with wet seasons and vice versa and this occurred throughout the study periods all over the study area. This study provides valuable insight on the spatial and temporal patterns of greenhouse gases concentration over Nigeria, the results revealed that there is significant increase (positive trend) in greenhouse gases over the country at 95% confidence level hence, the Greenhouse gases have been on the increase within the year of consideration. The study concluded that greenhouse gases concentration over Nigeria is an issue that government should take critical look at with a view to reducing it.