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 MannKendall 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 it 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, low value ozone 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.
