Microtopographic and eddy correlation data sets were obtained to measure the aerodynamic roughness length, Zou, the latter also used to measure the thermal roughness length, Zot. Microtopographic data from 70 measurement samples yielded a mean Zou value of 2.78 mm. Attempts to acquire as many half-hourly measurement samples from five-minute block means of eddy correlation data were frustrated by quasi-stationary flow conditions. Nevertheless, 18 samples from one eddy correlation sensor and 8 more from another yielded respective mean Zou values of 3.83 and 3.42 mm, as well as Zot samples. Plots of half-hourly mean ln(Zot/Zou) against the natural logarithms of the roughness Reynolds number appear to straddle the line of the Andreas surface renewal model, an observation that is reinforced when the stationarity selection criterion is relaxed to increase the number of points plotted. Suitable measurement conditions rarely occurred in the presence of a low-level katabatic wind speed maximum, which suggests that aspects of the measurement procedure may be useful in assessing the prominence of katabatic as opposed to geostrophic forcing of the glacier boundary-layer wind.