Atmospheric radio refractivity and water vapour density at Oshodi and Kano, Nigeria

Abstract

Some statistical analyses have been carried out on radiosonde data on atmospheric humidity taken during the period 1990-1993 at two meteorological stations, Oshodi (6° 32'N, 3° 21E) and Kano (12° 5N, 8° 52E) in Nigeria. Monthly means and standard deviations of columnar radio refractivity N and columnar water vapour density ρ have been obtained for the atmospheric columns, 0-3km, 0-10km, and 3-10km. It is found that the correlation coefficient between the monthly means of N and ρ is higher than 0.9 in most of the cases. Consequently, equations of regression have been obtained by means of which measurements of columnar water vapour density ρ can be used to estimate N over Oshodi, and Kano. For instance, line of regression of N upon ρ for Oshodi at the 0-3km atmospheric column is N = (4.93 ± 0.75) ρ + 254.15 ± 11.26.

Keywords: atmospheric humidity, columnar radio refractivity

Nigeria Journal of Pure and Applied Physics Vol. 4(1) 2005: 11-15