Assessment of atmospheric moisture using hygroscopic salts in dry-and-wet climate of Nigeria

Abstract

Atmospheric moisture content plays an important role in climate changes studies. Atmospheric moisture content was determined using four different hygroscopic salts, viz Sodium chloride (NaCl), Potassium chloride (KCl), Zinc sulphate (ZnSO4) and Magnesium chloride (MgCl2) salts and hygrometer. Evaluation of different hygroscopic salts for the determination of humidity was based on the ability of the salts to absorb atmospheric moisture. The affinity of salts for atmospheric water from measured value was compared with the hygrometer measured value. Data were subjected to one-way ANOVA using the Genstat statistical package (Release 4.24 Discovery Edition) to determine the weekly average of the moisture content and bulb depression. Duncan Multiple Range Test (DMRT), T-test and a linear regression model equation was generated with the fitness within 95%. The model of the regression was tested to determine the accuracy of equation compared with wet and dry bulb thermometer depression value. Magnesium chloride (MgCl2) offers the best result with significant coefficient (P = 0.01 and 0.05) and depression value of wet and dry bulb thermometer. The relative reliability of the use of hygroscopic salts in terms of accuracy of both measured and extrapolated humidity data utilization showed that these salts could be used in place of the usual hygrometer. Key words: Hygroscopic salts, hygrometer, atmospheric moisture, humidity.