Abstract:
The focus of this study is to evaluate the influence of Intertropical Discontinuity (ITD) on the variation of
Total column ozone (TCO). Relevant information is supplied on the temporal and spatial variability of TCO
along the ITD zone, which is an important factor influencing the earth's atmosphere. Several studies over
the years have established the relationship and influence several atmospheric processes have on TCO.
However, the relationship between Intertropical discontinuity and TCO over West Africa has a gap. This
study tends to examine the influence ITD has on TCO variation using the West Africa region as a case
study. The study used Wind, ozone and dewpoint temperature data for the period between 1980-2019.
To assess the variability and trend over the study region, several statistical methods were used, including
Pearson correlation, Mann-Kendall, and linear regression model. The Mann-Kendall test shows an
increasing trend throughout the months over the study region. Spatial analysis also revealed that regions
North of the ITD has a higher concentration of TCO that the southern region of the ITD. however, ITD influence was more visible during the wet month of June to August (JJA) as the highest concentration of
TCO was observed during this period across all latitude but more deviation was observed between latitude
100N to 180N, while the least occurrence is observed when ITD is at its minimum position in the month of
December to February (DJF). The ACRV shows that 140N exhibit the highest variation with a value of 4.84,
while the deviation is also at its highest with value of 13.65. The monthly position of ITD for Forty years
was also analysed to observe the monthly deviation along the ITD region forty years and the spatial
distribution of TCO was analysed from January to December. It’s of note that during the cause of this
study, ozone hole which is designated by concentration less than or equal to 220DU was not recorded.
The highest and the lowest value of TCO is 295DU and 227DU respectively with an average range of 68DU.
