Abstract

In this study, the monthly average mean temperature, relative humidity and surface pressure data obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) for a period of thirty-eight (1979 – 2016) years was employed to estimate the saturation mixing ratio and mixing ratio for Potiskum located in the Sahelian climatic zone of Nigeria. The monthly variation of saturation mixing ratio and mixing ratio with the meteorological parameters during the period under focused was investigated. The results revealed that the maximum and minimum values of saturation mixing ratio were found in the months of May and December with 31.7067 g kg-¹ and 17.5980 g kg-¹, respectively. The maximum and minimum values of saturation mixing ratio were found in the months of September and February with 20.6797 g kg-¹ and 4.1153 g kg-¹, respectively. The results showed that high values of mixing ratio were observed during the rainy season and low values during the dry season. The monthly variation of saturation mixing ratio with mean temperature and the monthly variation of mixing ratio with relative humidity depicts direct relationship. The monthly variation of saturation mixing ratio with atmospheric pressure and relative humidity and the monthly variation of mixing ratio with mean temperature and atmospheric pressure varies differently.

Key words: Saturation Mixing Ratio, Mixing Ratio, Meteorological Parameters, Potiskum, ECMWF.