Role of Turbulent Fuxes in the Surface Energy Balance of Glaciers of the Central Spitsbergen: The Case of Aldegondabreen

The results of verification of the aerodynamic method for calculating turbulent heat fluxes between the glacier and the atmosphere using the eddy covariance method are presented. The experiment was conducted on Aldegondabreen, Svalbard, in August 2022. Comparison of the methods showed a high agreement between the fluxes estimated by the two methods (R2 = 0.7), but the aerodynamic method underestimated the flux (with a mean error of 14%). The eddy covariance method allowed us to estimate the aerodynamic roughness length parameter for Aldegondabreen z0m = 0.8 mm, and the thermal roughness length z0h = 0.08 mm. The uncertainty analysis of the aerodynamic method revealed systematic errors related to the wind flow direction. The coefficient of proportionality was 0.67–0.70 for the wind direction along the glacier slope and 0.98 for the wind direction perpendicular to the glacier slope. Mean values of heat fluxes during the ablation season for the period 1991–2020 were calculated for Aldegondabreen: the shortwave balance is 72.6–113.8 W m–2; the longwave balance is 14.5 W m–2; the turbulent fluxes of sensible and latent heat determined by the aerodynamic method are 20.5 and about 1 W m–2, respectively. Thus, even allowing for a systematic method error of 14% (~3 W m–2), the total turbulent heat exchange of 24.5 W m–2 was lower than the mean estimates for the shortwave balance.