Estimation of Atmospheric Pressure from Dew Point at A Tropical Location, Ilorin, Kwara State, Nigeria

Abstract: Atmospheric pressure is the force per unit area exerted by the weight of the atmosphere. Dew point is the temperature to which air must be cooled to become saturated with water vapor, assuming constant air pressure and water content. In this research, the estimation of atmospheric pressure from dew point was conducted at an experimental site near the Physics/Electronics Unit laboratory at Kwara State Polytechnic, Ilorin, Nigeria. For the field observations, an instrumented Meteorological Weather Smart System was set up at an experimental site near the Physics/Electronics Unit laboratory, Kwara State Polytechnic, Ilorin, for a period of two weeks (20th May - 3rd June, 2022). The atmospheric pressure and dew point measurements from the Weather Smart System were recorded every 10 seconds and averaged over 2 2-minute intervals. The sampled data was then stored in the datalogger storage module. After removing spurious measurement values, the data stored was further reduced to hourly averages using Microcal Origin (version 7.0) data analysis software. In this research, the acquisition of the data was achieved by using Weather Smart datalogger systems (measurement and control module). An RS232 connection to the computer for communication purposes was achieved by using a USB cable. The datalogger is wirelessly connected to all the sensing elements, thereby accepting their respective signals. The transducers' signals were then sampled, digitized, and stored in the internal/expanded memory. The data, which were collated in ASCII format, were then reduced using a data reduction program, MicroCal Origin 7.0 Version. The results showed that the predicted atmospheric pressure, was compared with the actual measurements, and remarkably good agreement have been obtained with the MBE = 0.68 hpa; RMSE = 6.67 hpa , and r = 0.55. The parametric equation obtained in this research was found to be: