Influence of Temperature and Relative Humidity on Air Pollution in Addis Ababa, Ethiopia

Abstract

In this paper we access the effects of two atmospheric variables (temperature and relative humidity) on two important pollutants in the atmosphere (Nitrogen oxides (NOx) and carbon monoxide (CO)) by using one year (2016) data of Addis Ababa. Temperature has impact on atmospheric mixing and cause for the reduction of NOx as temperature increases. There are positive correlation between temperature and CO concentration from January to April with (R² = 0.69), negative correlation from May to August with (R² = 0.92) and no correlation for the remaining months. NO_x and CO have moderate positive and negative correlation with relative humidity during the months January-April (R² = 0.294 for NO_x and R² = 0291 for CO) and in the months May-August are R² = 0.97 and R² = 0.15 for NOx and CO respectively. But there are no clear correlation between the NOx and CO with relative humidity from September-December. NOx concentrations during wet season was almost about twice that of the dry season, but no such difference was observed in the case of CO. The seasonal average air temperature in wet season is relatively lower than dry season. NOx exhibited positive and CO negative seasonal correlations with relative humidity.