Abstract. Atmospheric stability has a significant effect on wind shear and turbulence intensity, and these variables, in turn, have a direct impact on wind power production and loads on wind turbines. It is therefore important to know how to characterize atmospheric stability in order to make better energy yield estimation in a wind farm. Based on research grade meteorological mast at Alaiz (CENER's Test Site in Navarre, Spain) named MP5, this work compares and evaluates different instrument set-ups and methodologies for stability characterization. The Obukhov parameter ζ = z/L, which can be measured locally with the use of a sonic anemometer, and bulk Richardson number have been studied. The methods are examined considering their theoretical background, implementation complexity, instrumentation requirements, and practical use in connection with wind energy applications. Bulk Richardson number, which is based on one height wind speed measurement and two temperature measurements, is sometimes calculated using values from any two temperature levels without taking into account that one of the measurements would be representative of surface conditions. With the data available in MP5, it will be shown how this approximation is not correct to obtain an adequate stability characterization.