Determination of Heat and Momentum Fluxes over Baghdad

Abstract

The heat and momentum fluxes have been determined at Al-Mustansiriyah University, Baghdad, Iraq, by using eddy correlation method. It is one of the methods which determines heat and momentum fluxes, it is considered direct and accurate. This method depends on high response instruments like Ultrasonic Anemometer (model: 1590- PK- 020). Observation period is about 53 days for 24 hours in months June, July and August (summer season) from 15/06/2016 to 06//08/2016 and the observations included wind speed and temperature every second. Huge data treated by MATLAB program to calculate heat and momentum fluxes (H and τ). The maximum value of H equals 127.6 Wm-2 in 10:30 at 26/07/2016 and minimum value equals -58.9 Wm-2 in 07:30 at 29/06/2016, as well, the maximum value of τ equals 0.134535 Nm-2 in 15:00 at 03/08/2016 and minimum value equals -0.4649 Nm-2 in 03:00 at 01/07/2016 (negative sign refer also to change in direction flow) . It is found that there is an inverse relationship between H and τ. Fractional drag by wind speed, also deal where Maximum frequency of friction velocity is at unstable conditions.