Low-level jets as monitored by a tri-axial acoustic sounder in Ile-Ife, Nigeria - Research Note

Abstract

A Sensitron tri-axial acoustic sounder has been used to monitor existence of low-level jets in the atmospheric boundary layer at Ile-Ife (7.5N, 4.5E), Nigeria. From about 400 sets of wind data processed for the period: June - September 1991, low-level jets of speeds ranging between 6.0ms^-1 and 12.50 ms^-1, were observed at the 220m, 330m, 650m and 700m heights. Also it was found that the jets were prominent only in the early hours, that is, 0400 – 0900 GMT, and in the late afternoons, 1400 – 1800 GMT.

The occurrences of the low-level jets are attributed to the influence of positive temperature gradient (i.e. the temperature inversion) on the wind speed as associated with the nocturnally varying phenomena.

Ife Journal of Science Vol.6(2) 2004: 203-206