Estimation of the surface energy balance in the Sahelian zone of Western Africa

Abstract

Søgaard, Henrik: Estimation of the surface energy balance in the Sahelian zone of Western Africa. Geografisk Tidsskrift 88: 108- 115. Copenhagen 1988.

In studies of desertification in the Sahelian zone of Western Africa an improved knowledge of the water and surface energy balance is recognized to be of major importance. Based on micro-climatological measurements collected during an ongoing field study in the northern part of Burkina Faso, a number of methods for deriving surface energy balance are examined. It is found that for the actual case, with profile measurements restricted to two levels above the surface, exact values of the sensible heat flux can accurately be obtained by applying non-dimensional gradients based on the Monin-Obukhov turbulence theory. Utilization of the results for deriving actual evapotranspiration from standard observations is demonstrated, and the paper finally discusses applicability of the results in satellite remote sensing.

Keywords:

• Climatology
• Energy balance
• Sahel
• Desertification
• Actual evapotranspiration
• Sensible heat flux